Some standard content:
China State Shipbuilding Corporation Department Standard
CB 1338-98
Technical requirement of communication antenna for naval ship
Technical requirement of communication antenna for naval ship1998-03-20Issued
China State Shipbuilding Corporation
Implementation on 1998-08-01
1 Scope
1.1 Subject Content
China State Shipbuilding Corporation Department Standard
Technical requirement of communication antenna for naval ship
Technical requirement of communication antenna for naval shipThis standard specifies the general technical requirements for ship communication antennas. 1.2 Scope of Application
CB1338-98
Classification Number: U66
This standard applies to the research, design and production of ship communication antennas (hereinafter referred to as antennas), and can be used as the basis for formulating corresponding product specifications.
2 Reference documents
7 Terminology of radio and television Radio broadcasting
GB7400.2-87
GJB 367.187
GJB367.2-87
General technical conditions for military communication equipment
: Design and manufacturing requirements
General technical conditions for military communication equipment
Environmental test methods
Requirements for packaging, transportation and storage
GJB 367.5-87
General technical requirements for military communication equipment
GJB431-88 Product hierarchy, product interchangeability, prototypes and related terms and climate, biological, chemically active substances and mechanical agentsGJB440.1-88 Classification of environmental parameters for ship equipment and their severity levelsGJB440.2-88
Classification of environmental parameters for ship equipment and their severity levelsGJB450-88 General outline for the reliability of equipment development and productionG JB451-90 Reliability maintenance terminology
SJ2534.1-84 Antenna test method Test equipment for antenna test field SJ2534.3-84 Antenna test method Measuring antenna radiation pattern at antenna test field "Standardization work regulations for weapon equipment development" February 1990 National Defense Science, Technology and Industry Commission 3 Definitions
3.1 Terms
For any terms not defined in this standard, GB7400.2, GJB431 and GJB451 shall prevail. 3.1.1 Antenna
Components used to transmit or receive electromagnetic waves in the ship's sending or receiving system and their insulation, support and motion mechanisms. 3.1.2 Antenna input impedance
The impedance presented by the antenna input end. Its value is equal to the ratio of the input voltage to the current, usually a complex quantity. 3.1.3 Antenna polarization
The polarization of the wave radiated by the antenna in a given direction relative to itself. For receiving antennas, it refers to the polarization of a plane wave incident from a given direction and with a given power density, which results in the maximum available power at the antenna output terminal connection point. If the direction is not specified, it refers to the polarization in the direction of maximum gain.
Approved by China State Shipbuilding Corporation on March 20, 1998 and implemented on August 1, 1998
CB1338-98
The polarization of a wave refers to the characteristics of the direction and relative magnitude of the electric field vector of the radiated electromagnetic wave changing with time. 3.1.4 Suspicious band
The corresponding frequency band when the measured voltage standing wave ratio value is close to the maximum allowable voltage standing wave ratio Smax (Smax ± 0.08) 3.1.5 Antenna effective length
For a linearly polarized antenna receiving a plane wave from a given direction, it refers to the ratio of the amplitude of the open circuit voltage generated at the antenna output terminal to the amplitude of the electric field strength in the polarization direction of the antenna. When the antenna is an upright antenna, the effective length is also called the effective height. However, care should be taken not to confuse it with the height of the antenna radiation center from the ground (also called effective height) used at high frequencies. 3.1.6 Operating frequency range
The frequency range in which the relevant electrical properties of the antenna meet the specified requirements. 3.1.7 Antenna noise temperature
At a specific frequency, the temperature of a resistor with an effective thermal noise power per unit bandwidth equal to that at the output end of the closed line. The noise temperature of the antenna depends on the coupling of the antenna with all noise sources in the surrounding environment and the noise generated in the antenna. 3.1.8 Antenna Q value
The ratio of 2 times the energy stored in the antenna excitation field to the radiated and dissipated energy in one resonant cycle. For electrically small antennas, this value is equal to half of the amplitude of the ratio of the impedance increment to the corresponding resonant frequency increment divided by the ratio of the antenna resistance to the resonant frequency. 3.1.9 Antenna effective area (aperture)
The ratio of the output power at the output end of the receiving antenna to the power density per unit area of the vertically incident plane wave is the effective area of the antenna, also called the effective aperture.
3.1.10 Damage
Cracks or cracks in the antenna's external or internal structure, dielectric breakdown and insulation breakdown, as well as dielectric degeneration or structural deformation that may lead to irreversible electromechanical performance.
3.1.11 Performance degradation
Any degradation of mechanical or electrical performance that does not meet the specified values. 4 General requirements
4.1 Standardization requirements
In the entire process of antenna development and production, the "Standardization Work Regulations for Weapon Equipment Development" and relevant standards should be conscientiously implemented. 4.2' Design and manufacturing requirements
The design and manufacture of antennas should fully consider the antenna's tactical and technical requirements or the provisions of product specifications. Use standard parts, general parts and transfer parts to the maximum extent possible. Consider environmental impact to make it more adaptable. And carry out reliability, electromagnetic compatibility, maintainability, interchangeability, safety and usability design.
On the premise of meeting the antenna performance requirements, the processing methods of its parts, components and assemblies should be simple and safe, and the raw materials and energy consumption should be low. When adopting new processes and technologies, they should be proved through tests that they can guarantee the product quality requirements, and they can be put into use only after identification. 4.2.1 Material requirements
4.2.1.1 The materials should be based on domestic sources. The brand, specification and state of the materials should be optimized as much as possible. 4.2.1.2 The substitution of materials should ensure the performance of the antenna, and new trial-produced materials that have not been identified and qualified shall not be used. 4.2.2 Requirements for antenna components and parts
The selection of components, parts, spare parts and accessories should meet the requirements of the corresponding standards (national standards or national military standards, professional standards). Non-standard parts should have complete design documents and can only be used after inspection or identification. 4.2.3 Surface treatment requirements
The surfaces of all parts, components, assemblies and devices in the antenna that may be corroded should be surface plated or chemically treated. However, the coating or chemical treatment layer used should not affect the electromechanical performance of the antenna. 4.2.4 Electromagnetic compatibility requirements
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Unless otherwise specified, the antenna should comply with the overall electromagnetic compatibility requirements of the ship. 4.2.5 Reliability requirements
4.2.5.1 The reliability index of the antenna is specified by the product tactical and technical requirements or product specifications. 4.2.5.2 Reliability design should be carried out simultaneously with the design to achieve the electromechanical requirements specified in this standard. 4.2.5.3 Antenna development should prepare a reliability assurance outline in accordance with the requirements of GJB450 so that the antenna can meet the corresponding reliability requirements. 4.2.6 Assembly and installation requirements
4.2.6.1 Assembly should ensure that the actual object is consistent with the assembly drawing and process documents. All changes and replacements of materials and electromechanical parts, components and processes must go through the approval procedures in accordance with the prescribed procedures. 4.2.6.2 All electromechanical parts, components and purchased parts submitted for assembly shall comply with the requirements of current standards and design documents and may only be used after passing the inspection.
4.2.6.3 According to the precision of the antenna and the characteristics of the assembled parts and components, corresponding requirements shall be put forward for the environmental conditions and operation methods of the assembly site. Any damage to the assembled parts and performance degradation during the assembly process shall not be allowed. 4.2.6.4 When the antenna is installed overhead, the strength and rigidity of the support shall be considered. 4.2.6.5 The antenna shall be easy to disassemble and install on the premise of meeting the product tactical and technical requirements or product specifications. 4.2.7 Maintainability requirements
The maintainability index (mean time to repair MTTR) of the antenna shall be specified in the product tactical and technical requirements or product specifications. The configuration of each part of the antenna shall be comprehensively arranged according to its failure rate, difficulty of maintenance, size and weight, and installation characteristics. All parts and components that need to be inspected, maintained, disassembled or repaired shall have good accessibility. Emergency switches and access openings should be installed for parts with high failure rates and frequent maintenance, and should provide optimal accessibility. 4.2.7.1 The general and specific maintainability requirements of antennas shall comply with the following maintenance principles: a. To minimize the complexity of maintenance work, simple design shall be used to the maximum extent, including the best interchangeability and use of standard parts; b. The technical level required for maintenance shall be minimized during design; c. The types and quantities of tools and test equipment (specific or standard) required to complete maintenance tasks shall be minimized during design;
d. The most accessible design scheme shall be adopted for all components that need to be repaired, inspected, disassembled and replaced; e. The safest design scheme for personnel and equipment involved in maintenance shall be adopted; f. The average time required to complete scheduled and unscheduled maintenance and component replacement shall be short enough to ensure that the antenna has the required working efficiency.
4.2.7.2 Any antenna or component that is not specified as a repairable product shall be considered as non-repairable and shall be replaced once damaged. High reliability or low-cost components shall be designed to be non-repairable. 4.3 Marking, packaging, transportation, storage
Unless otherwise specified, it shall generally comply with the relevant requirements of GJB367.5. 4.4 Economic requirements
Comprehensive demonstration should be conducted on the performance, life, manufacturing cost, maintenance and use cost of the antenna. Under the premise of ensuring that the specified antenna performance and quality reliability requirements are met, a reasonable structure and production type should be adopted to reduce costs and improve the performance-price ratio. 5 Detailed requirements
The following requirements can be tailored as needed. 5.1 Environmental requirements
Unless otherwise specified, the environmental requirements of the antenna shall comply with the following provisions. 5.1.1 Ambient temperature
5.1.1.1 Operating temperature range: -30~60℃. 3
5.1.1.2 Storage temperature range: -50~65℃5.1.2 Temperature change (air/water)
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The antenna shall comply with the relevant provisions in Table 3 of GJB440.1. 5.1.3 Mixed
Antennas shall comply with the provisions of Article 1.2.1.2 of GJB367.1. 5.1.4 Wind speed
Antennas shall be designed or manufactured according to the following wind speeds: when the relative wind speed is 40m/s, the antenna shall work normally; when the relative wind speed is 54m/s, the antenna shall not be damaged.
5.1.5 Rain
Antennas shall comply with the provisions of Item 410 of GJB367.2. 5.1.6 Ice and snow
Antennas shall comply with the provisions of Article 1.2.1.4 of GJB367.1. 5.1.7 Impact, shock and vibration
Antennas shall comply with the provisions of Items 408 and 409 of GJB367.2 on the severity level of shipborne communication equipment tests. 5.1.8 Tilt and swing
Antennas shall generally comply with the relevant provisions of Table 4 of GJB440.2. 5.1.9 Salt spray
The antenna shall comply with the relevant provisions of item 413 of GJB367.2. 5.1.10 Solar radiation
The antenna shall comply with the relevant provisions of item 404 of GJB367.2. 5.1.11 Fungi and other organisms
The influence of fungi should be considered when designing or manufacturing antennas. Antennas installed outside submarines should also consider the influence of marine organisms and the invasion of other animals to prevent damage to the antenna or degradation of performance. 5.2 Electrical performance requirements
Unless otherwise specified, the following performance index requirements are the values at the antenna measurement site. 5.2.1 Antenna input impedance
When designing and manufacturing antennas, it should be possible to make it easy to match with the feeder within the specified operating frequency range. 5.2.2 Voltage standing wave ratio
Unless otherwise specified, the voltage standing wave ratio of the antenna should be based on the input end of the antenna. When the octave is greater than 2, the voltage standing wave ratio of the antenna is generally not greater than 3 within the specified operating frequency range; when the octave is not greater than 2, the voltage standing wave ratio is generally not greater than 2. The voltage standing wave ratio of the receiving antenna is generally not specified.
5.2.3 Directivity diagram
The directivity diagram of the antenna shall meet the requirements of the product tactical and technical requirements or product specifications. 5.2.4'Gain
The antenna gain shall be specified by the product tactical and technical requirements or product specifications. Unless otherwise specified, the antenna gain generally refers to the power gain in the direction of the maximum radiation (reception) of the antenna.
5.2.5 Power capacity
The transmitting antenna shall be able to operate normally under the maximum RF power specified by the product tactical and technical requirements or product specifications. Generally, the specific power capacity value shall be specified, and it shall be indicated whether it is instantaneous power or average power. If necessary, different power capacity requirements may also be proposed for different operating frequency ranges.
5.2.6 Polarization of antenna
The polarization of antenna must be consistent with the polarization specified in the product tactical and technical requirements or product specifications. 5.2.7 Insulation resistance
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The insulation resistance of antenna shall meet the value specified in the product tactical and technical requirements or product specifications. Unless otherwise specified, the insulation resistance of the transmitting antenna shall not be less than 10Mα on a sunny day and shall not be less than 1Ma on a rainy day. The insulation resistance of the receiving antenna shall generally be not less than 0.5MQ on a rainy day. When the submarine antenna is working in the periscope state, its insulation resistance generally refers to the value after the antenna is out of water for 20s.
5.2.8 Effective length of antenna
The effective length of antenna is specified by the product tactical and technical requirements or product specifications. 5.2.9 Q value of receiving antenna
When designing the antenna, the factors affecting the Q value should be fully considered and the Q value of the antenna should be increased as much as possible. When used on the surface, the Q value of the ferrite antenna is at least 60, and at least 20 in the periscope state. 5.2.10 Receiving antenna noise temperature
When designing the antenna, the noise source should be analyzed according to the specific conditions such as the antenna's directivity, gain, and operating frequency, and corresponding measures should be taken to minimize the antenna noise temperature.
5.3 Mechanical performance requirements
5.3.1 Load
The design, manufacture and installation of the antenna should be able to withstand the loading load of wind, ice and snow, and the inertial force of the ship's swaying caused by wind and waves, and can withstand the maximum comprehensive stress imposed by the working environment such as explosion impact. Submarine antennas must be able to withstand the seawater pressure during deep diving and the dynamic loads during submarine diving, underwater navigation and vibration, and can withstand the periodic changes in pressure caused by changes in the submarine's working depth. 5.3.2 Mechanical movement
5.3.2.1 The transmission mechanism should be able to operate flexibly, accurately and smoothly, with good meshing, and no jamming, stringing, jumping, etc. The working noise shall comply with relevant regulations.
5.3.2.2 Frequently moving parts shall ensure flexible and stable operation. Frequently installed and disassembled parts shall be easy to install and disassemble. The movement mechanism is required to move normally.
The time of various movements of the moving parts of the antenna shall meet the product tactical and technical requirements or the provisions of the product specifications. 5.3.2.3
5.3.3 Mechanical connection
5.3.3.1 Mechanical connection shall comply with the provisions of Articles 2.3 and 2.4 of GJB367.1. 5.3.3.2 All parts of the antenna assembly that require transmission of RF current or have high current density on the surface during operation must have smooth, clean and good contact on all connection surfaces.
5.3.4 Corrosion protection
5.3.4.1 Surface treatment
The surface treatment shall comply with the provisions of Articles 2.5 and 2.7 of GJB367.1. 5.3.4.2 Coating
5.3.4.2.1 Coating can be implemented in accordance with the relevant provisions of Article 2.6 of GJB367.1. 5.3.4.2.2 No unacceptable electrochemical couples shall be formed between the coating metal and the base metal, or between the parts in contact. If it cannot be avoided, necessary protective measures shall be taken between the two connectors. 5.3.4.3 Color
In the same antenna, all parts, components and assemblies of the same color shall be consistent in color, but color difference within the range specified in the standard sample is allowed.
5.3.5 Sealing and pressure resistance
5.3.5.1 All exposed moving surfaces and antenna feed connectors shall be properly sealed according to the use requirements to prevent dust, moisture, water, corrosive salt-containing gas and other pollutants from entering.
5.3.5.2 When airtightness is required, its leakage rate shall comply with the product tactical and technical requirements or product specifications. 5.3.5.3 The hydraulic system should take good sealing measures to ensure that the antenna has no external leakage under the rated working pressure required by the design and within the specified time.
5.3.6 Anti-natural resonance
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Antenna design should consider preventing the natural resonance between the antenna and the hull. 5.4 Special requirements for active antennas and planar antennas Special requirements for active antennas and planar antennas are specified by product tactical technical requirements or product specifications. 5.5 Electrical performance measurement requirements
5.5.1 Requirements for the measurement site
a. The measurement site should be as open as possible, and there should be no power lines, tall buildings, or other objects that reflect electromagnetic waves nearby; b. When designing the measurement site for measuring ship communication antennas, a metalized ideal conductive plane is generally used to simulate the sea surface. The grounding resistance of this ideal conductive plane should generally not be greater than 1Ω; c. The measurement distance between the auxiliary measurement antenna and the antenna to be measured should meet the requirements of formulas (1) and (2) at the same time; R≥10
R≥2L.+L)
In formulas (1) and (2): R-the distance between the auxiliary measurement antenna and the antenna to be measured, m; L-the maximum size of the antenna to be measured, m;
L. —the maximum size of the auxiliary measurement antenna, m; λ-the wavelength corresponding to the measurement frequency, m.
In the actual application of measuring small antennas, if only general measurement accuracy is required, R greater than or equal to 5λ is sufficient. (1)
d. When measuring the antenna input impedance and voltage standing wave ratio, the distance between the antenna to be tested and the reflecting object in all directions should satisfy the conditions of formulas (3) and (4) at the same time.
R≥C,Ga·f(.@)·入
R≥C,L
In formulas (3) and (4):
R is the distance between the antenna to be tested and the reflecting object, m; Ga
f(9,@)
is the gain coefficient of the antenna to be tested relative to the lossless half-wave dipole in free space, expressed in multiples; (3)
is the normalized directivity function of the antenna to be tested, and Φ is the elevation angle and azimuth angle of the reflecting object calculated from the maximum radiation direction of the antenna to be tested, (°); the accuracy factor, the value of which is shown in Appendix A (Supplement); the maximum size of the antenna to be tested, m;
is the wavelength corresponding to the measurement frequency, m.
5.5.2 Requirements for measuring equipment
According to the specific measurement requirements, select the corresponding measuring equipment according to the provisions of SJ2534.1. 5.5.3 Measurement of model antenna
5.5.3.1 The model antenna must meet the following conditions to simulate the performance of the prototype antenna. When the proportionality factor is n, the simulation conditions that need to be followed are as follows: a. The size of the model antenna should be 1/n times the size of the prototype antenna; b. The operating frequency of the model antenna and the conductivity of the material used should be n times that of the prototype antenna; c. The dielectric constant and magnetic permeability of the material used for the model antenna are the same at the proportional frequency and the original frequency. In practice, condition b. may not be fully met. When the antenna radiation resistance is much larger than the loss resistance, the model antenna can be made of copper, aluminum or silver-plated materials with high conductivity, and the error is usually small. 5.5.3.2 The value of the proportionality factor n should be selected based on factors such as the size of the measurement site, the available measurement equipment and the required measurement accuracy.
5.5.3.3 As required, sometimes the model antenna needs to be installed on a ship (or relevant part of a ship) model of corresponding proportion to measure the antenna performance.
The ship (or relevant part of a ship) model should contain those components that obviously affect the measurement results. 5.5.4 On-site measurement of antenna electrical performance
The measurement of antenna electrical performance is generally completed at the measurement site. Sometimes, as required, some performance can also be measured at the installation site. If on-site measurement is required, it should be specified in the product tactical technical requirements or product specifications. The measurement conditions and specific requirements of on-site measurement are specified by a special test outline. 5.5.5 Measurement of input impedance and voltage standing wave ratio The input impedance of the antenna can be directly measured using various impedance measuring instruments used in radio and microwave measurements. Generally, Q meters, slotted lines, impedance bridges and automatic network analyzers are used. In addition to being measured by slotted lines and automatic network analyzers, voltage standing wave ratio can also be measured by standing wave ratio meters and power meters. The choice of measuring instruments mainly depends on the applicable frequency of the intended instrument. However, no matter what instrument is used, the measurement site should meet the requirements of Article 5.5.1. Sometimes, in order to obtain antenna input impedance or voltage standing wave ratio that is closer to the actual value, measurements should also be carried out on a real ship or in accordance with the provisions of Article 5.5.3.1. Unless otherwise specified, in the frequency range of 3 to 30 MHz, the measurement frequency increment should generally not exceed 1 MHz; in the frequency range of 30 to 500 MHz, the frequency increment should not exceed 10 MHz; in the frequency range of 500 to 1000 MHz, the frequency increment should not exceed 25 MHz; when the frequency is lower than 3 MHz, the frequency increment should be small enough to determine a smooth (standing wave ratio-frequency) curve. If the measured voltage standing wave ratio value falls into the suspicious band, the standing wave situation in the 10% frequency band around the frequency point should be studied in detail. 5.5.6 Measurement of Directivity Pattern
Unless otherwise specified, the measurement of antenna directivity pattern is generally completed at the measurement site. 5.5.6.1 Measurement of Horizontal Plane Directivity Pattern
Measurement of antenna horizontal plane directivity pattern at the antenna measurement site shall be carried out in accordance with the provisions of SJ2534.3. 5.5.6.2 Measurement of Vertical Plane Directivity Pattern
Measurement of antenna vertical plane directivity pattern at the antenna measurement site shall be carried out in accordance with the provisions of SJ2534.3. 5.5.7 Measurement of Gain
Antenna gain is generally measured by comparison method. The measurement can be carried out in free space measurement field or ground reflection measurement field. A pair of standard gain antennas must be available during measurement, and the antenna to be measured can be used as a transmitting antenna or a receiving antenna. 5.5.7.1 Measurement Conditions
5.5.7.1.1 In addition to meeting the requirements of Article 5.5.1, the measurement site shall also meet the specific requirements of free space site and ground reflection site.
5.5.7.1.2 The standard gain antenna should have the following characteristics: a. The gain should be accurately known;
b. The antenna has a high degree of dimensional stability; c. The antenna should be linearly polarized, and in some applications it can also be circularly polarized. If it is circularly polarized, two antennas are required, one is left-hand circularly polarized and the other is right-hand circularly polarized. Whether linearly polarized or circularly polarized, the antenna should have high polarization purity. 5.5.7.1.3 The auxiliary antenna and standard gain antenna used in the measurement should be polarization matched with the antenna to be measured, and the standard gain antenna and the antenna to be measured should have the same feeding conditions. 5.5.7.1.4 The output power and frequency of the measurement signal source should have sufficient stability, and the measurement receiver should have sufficient sensitivity and dynamic range.
5.5.7.2 Measurement steps
The measurement should be carried out in a matched state.
5.5.7.2.1 The antenna to be tested and the standard gain antenna are used as transmitting antennas for measurement: a. The measurement block diagram is shown in Figure 1;
Attenuator
Precision variable
Attenuator
Signal source
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Standard gain antenna
Auxiliary receiving antenna
Antenna to be tested
Detector
R-the distance between the antenna to be tested and the auxiliary receiving antenna Rmin-the minimum distance that satisfies formulas (1) and (2) Figure 1 Block diagram when the antenna to be tested is used as a transmitter
Amplifier
Indicating ammeter
b. Connect the measuring instruments and equipment as required in Figure 1 and align the antenna to be tested, the standard gain antenna and the auxiliary receiving antenna respectively. Connect the antenna to be tested and the standard gain antenna to the signal source in turn, and adjust the variable attenuator to make the receiving indicating device (electric meter, frequency selective amplifier or measuring receiver) have appropriate indication. Under the condition of maintaining the same indication level in the two states, use a power meter to measure the input powers Px and Ps of the antenna to be tested and the standard gain antenna respectively, or directly record the readings Ax and As of the precision variable attenuator in the two states. If the gain of the standard gain antenna is known to be Gs, the gain Gx of the antenna to be tested is obtained by formula (5) or formula (6): Gx = Gs + 10 × lg·p
Gx = Gs + Ax - As
In formulas (5) and (6): Gx
gain of the antenna to be tested, dB;
Gs gain of the standard gain antenna, dB;
Ps - input power of the standard gain antenna, mW; - input power of the antenna to be tested, mW;
Ax - reading of the variable attenuator when receiving the antenna to be tested, dB; As - reading of the variable attenuator when connected to the standard gain antenna, dB. 5.5.7.2.2 The antenna under test and the standard gain antenna are used as receiving antennas for measurement: a.The measurement block diagram is shown in Figure 2;
Condenser
Signal source
Auxiliary transmitting antenna
Standard gain antenna
Precision variable
Antenna to be tested
Power meter
R-the distance between the antenna to be tested and the auxiliary transmitting antenna Rmin-the minimum distance that satisfies formulas (1) and (2) Figure 2 Block diagram of the antenna to be tested when used for receiving
Indicating ammeter
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b. The specific steps are basically the same as when the antenna to be tested is used for transmitting, except that when the signal source maintains the same power, the receiving powers Px and Ps of the antenna to be tested and the standard gain antenna are measured respectively. The gain of the antenna to be tested is obtained by formula (7): Gx = Gs + 10 × lg
Wherein: Gx is the gain of the antenna to be tested, dB;
Gs is the gain of the standard gain antenna, dB;
Px is the received power of the antenna to be tested, mW;
..· (7)
Ps is the received power of the standard gain antenna, mW. In addition, the readings Ax and As of the precision variable attenuator when the antenna to be tested and the standard gain antenna are connected can be recorded respectively when the signal source maintains the same power and the two states have the same indication level, and then the gain of the antenna to be tested can be calculated by formula (6). 5.5.7.2.3 Measurement of circularly polarized and elliptically polarized antenna gain. For shipboard non-linearly polarized communication antennas, a linearly polarized standard gain antenna and a linearly polarized auxiliary antenna with relatively high polarization purity can be used to measure the gain of the elliptically polarized antenna. The configuration block diagram during measurement is the same as Figure 2. Use the precision variable attenuator reading. If the standard gain antenna is aligned with the auxiliary antenna, the precision variable attenuator reading is As. Connect the elliptically polarized antenna and keep the same indication level as the standard gain antenna, and the precision variable attenuator reading is Ax1. Rotate the polarization of the linear polarized auxiliary antenna by 90°, and the precision variable attenuator reading is Ax2 at the same indication level as above. Then the gain of the elliptically polarized antenna to be tested is obtained by formula (8):
Gx = Gs + Ax - As +10 X Ig(1 + 10% If the antenna to be tested is a circularly polarized antenna, formula (8) can be simplified to Gx = Gs + Axi - As + 3
In formulas (8) and (9): Gx
Gain of the antenna to be measured, dB;
GsGain of the standard gain antenna, dB;
AsThe reading of the variable attenuator when connected to the standard gain antenna, dB; Ax1—The reading of the variable attenuator when connected to the elliptically polarized antenna, dB; Ax2
5.5.7.3 Measurement error
The reading of the variable attenuator after the auxiliary antenna is rotated 90°, dB. (8)
5.5.7.3.1 Main error factors||t t||In addition to the main errors in gain measurement caused by the instrument itself, feeder loss and limited measurement distance, impedance mismatch and polarization mismatch will also introduce measurement errors, which should be corrected when necessary. 5.5.7.3.2 Impedance mismatch error
When measuring antenna gain by comparison method, the impedance mismatch between the signal source and the connected antenna, and between the receiver and the connected antenna can be corrected by adding correction items.
When the antenna to be measured is used as a receiving antenna, the actual measured gain is calculated according to formula (10): +10×lgM
Gx=Gs+ 10 ×lg
（10)
Wherein: Gx
gain of the antenna to be tested, dB;
gain of the antenna with standard gain, dB;
-received power of the antenna to be tested, mW;
Ps-received power of the antenna with standard gain, mW; Mrx-impedance mismatch correction factor of the antenna to be tested; Mrs-impedance mismatch correction factor of the antenna with standard gain. Mrx and Mrs are obtained from formulas (11) and (12): Mrx
(1-x)(1 -(1)
（11)
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(1-(1 -)
In formulas (11) and (12): rx—reflection coefficient of the antenna to be measured; Ts—reflection coefficient of the standard gain antenna;
T—reflection coefficient of the receiver.
5.5.7.3.3
3 Polarization mismatch error
When measuring, the polarization mismatch of the transmitting and receiving antennas makes the measured gain greater or less than the actual value. It is necessary to introduce polarization efficiency to correct the measured gain.
When measuring antenna gain using the comparison method, if polarization mismatch needs to be considered, use the antenna to be measured as the receiver. Taking the receiving antenna as an example, the gain of the antenna to be tested can be corrected to formula (13):
+10×lg
Gx=Gs+10×lg
Wherein: Gx is the gain of the antenna to be tested, dB; Gs is the gain of the standard gain antenna, dB;
is the received power of the antenna to be tested, mW;
is the received power of the standard gain antenna, mW;
is the polarization efficiency of the incident wave of the standard gain antenna; s
7x is the polarization efficiency of the incident wave of the antenna to be tested. 5.5.8 Measurement of power capacity
(13)
In view of the wide variety of antenna structures and working environment conditions, this standard does not specify the specific measurement steps of power capacity, but only proposes the following measurement requirements.
5.5.8.1 Working environment simulation
The environmental conditions during the power capacity measurement should be the same as those during the actual operation of the antenna. If some environmental conditions such as temperature and humidity do not meet the requirements, they must be simulated. The measurement should be carried out in an appropriate simulation environment. 5.5.8.2 Power source for measurement
The performance parameters of the power source for measurement, such as modulation, pulse width, pulse waveform, pulse repetition frequency, etc., should be the same as the parameters of the transmitter used for the actual operation of the antenna, and these parameters should not change during the measurement due to different applied power levels. 5.5.8.3 Preparation before measurement
Before measurement, the antenna to be measured and its accessories should be inspected to remove possible burrs, dirt, metal debris, water film, rust, etc. 5.5.8.4 Monitoring and Observation
During measurement, instruments or personnel should be used to directly observe whether the temperature rise of the relevant dielectric or metal key parts of the antenna is within the allowable range within the specified time after the rated power is applied, and whether there is arcing, corona discharge or breakdown in various parts of the antenna. During measurement, necessary safety measures should be taken to prevent test personnel from being injured. 5.5.8.5 Alternative method
When the above conditions are not met, the power capacity performance can be evaluated by measuring the RF voltage and RF current in combination with system coordination.
5.5.9 Polarization measurement
5.5.9.1 Polarization pattern measurement
Measurements related to polarization are generally completed in free space. 5.5.9.1.1 The antenna to be tested is in the transmitting state. The linear polarization detection antenna is rotated in a plane perpendicular to the incident direction. The polarization pattern can be obtained by recording the relationship between the relative voltage /U| of the detection antenna receiving signal and the rotation angle of the detection antenna. An example of the polarization pattern is shown in Figure 3. The major axis and minor axis of the polarization ellipse can be obtained from the polarization pattern, and the axial ratio and inclination angle t of the incident wave can be determined from it.3 Measurement of circular polarization and elliptically polarized antenna gain. For shipboard non-linear polarization communication antennas, a linear polarization standard gain antenna and a linear polarization auxiliary antenna with relatively high polarization purity can be used to measure the elliptically polarized antenna gain. The configuration block diagram for measurement is the same as Figure 2. Use the precision variable attenuator reading. If the standard gain antenna is aligned with the auxiliary antenna, the reading of the precision variable attenuator is As; connect the elliptically polarized antenna and maintain the same indication level as the standard gain antenna, and the reading of the precision variable attenuator is Ax1; rotate the polarization of the linear polarization auxiliary antenna by 90°, and the reading of the precision variable attenuator is Ax2 at the same indication level as the above. The gain of the elliptically polarized antenna to be measured is obtained by formula (8):
Gx = Gs + Ax - As +10 X Ig(1 + 10% If the antenna to be measured is a circularly polarized antenna, formula (8) can be simplified to Gx = Gs + Axi - As + 3
In formulas (8) and (9): Gx
Gain of the antenna to be measured, dB;
GsGain of the standard gain antenna, dB;
AsThe reading of the variable attenuator when connected to the standard gain antenna, dB; Ax1—The reading of the variable attenuator when connected to the elliptically polarized antenna, dB; Ax2
5.5.7.3 Measurement error
The reading of the variable attenuator after the auxiliary antenna is rotated 90°, dB. (8)
5.5.7.3.1 Main error factors||t t||In addition to the main errors in gain measurement caused by the instrument itself, feeder loss and limited measurement distance, impedance mismatch and polarization mismatch will also introduce measurement errors, which should be corrected when necessary. 5.5.7.3.2 Impedance mismatch error
When measuring antenna gain by comparison method, the impedance mismatch between the signal source and the connected antenna, and between the receiver and the connected antenna can be corrected by adding correction items.
When the antenna to be measured is used as a receiving antenna, the actual measured gain is calculated according to formula (10): +10×lgM
Gx=Gs+ 10 ×lg
（10)
Wherein: Gx
gain of the antenna to be tested, dB;
gain of the antenna with standard gain, dB;
-received power of the antenna to be tested, mW;
Ps-received power of the antenna with standard gain, mW; Mrx-impedance mismatch correction factor of the antenna to be tested; Mrs-impedance mismatch correction factor of the antenna with standard gain. Mrx and Mrs are obtained from formulas (11) and (12): Mrx
(1-x)(1 -(1)
（11)
CB133898
(1-(1 -)wwW.bzxz.Net
In formulas (11) and (12): rx—reflection coefficient of the antenna to be measured; Ts—reflection coefficient of the standard gain antenna;
T—reflection coefficient of the receiver.
5.5.7.3.3
3 Polarization mismatch error
When measuring, the polarization mismatch of the transmitting and receiving antennas makes the measured gain greater or less than the actual value. It is necessary to introduce polarization efficiency to correct the measured gain.
When measuring antenna gain using the comparison method, if polarization mismatch needs to be considered, use the antenna to be measured as the receiver. Taking the receiving antenna as an example, the gain of the antenna to be tested can be corrected to formula (13):
+10×lg
Gx=Gs+10×lg
Wherein: Gx is the gain of the antenna to be tested, dB; Gs is the gain of the standard gain antenna, dB;
is the received power of the antenna to be tested, mW;
is the received power of the standard gain antenna, mW;
is the polarization efficiency of the incident wave of the standard gain antenna; s
7x is the polarization efficiency of the incident wave of the antenna to be tested. 5.5.8 Measurement of power capacity
(13)
In view of the wide variety of antenna structures and working environment conditions, this standard does not specify the specific measurement steps of power capacity, but only proposes the following measurement requirements.
5.5.8.1 Working environment simulation
The environmental conditions during the power capacity measurement should be the same as those during the actual operation of the antenna. If some environmental conditions such as temperature and humidity do not meet the requirements, they must be simulated. The measurement should be carried out in an appropriate simulation environment. 5.5.8.2 Power source for measurement
The performance parameters of the power source for measurement, such as modulation, pulse width, pulse waveform, pulse repetition frequency, etc., should be the same as the parameters of the transmitter used for the actual operation of the antenna, and these parameters should not change during the measurement due to different applied power levels. 5.5.8.3 Preparation before measurement
Before measurement, the antenna to be measured and its accessories should be inspected to remove possible burrs, dirt, metal debris, water film, rust, etc. 5.5.8.4 Monitoring and Observation
During measurement, instruments or personnel should be used to directly observe whether the temperature rise of the relevant dielectric or metal key parts of the antenna is within the allowable range within the specified time after the rated power is applied, and whether there is arcing, corona discharge or breakdown in various parts of the antenna. During measurement, necessary safety measures should be taken to prevent test personnel from being injured. 5.5.8.5 Alternative method
When the above conditions are not met, the power capacity performance can be evaluated by measuring the RF voltage and RF current in combination with system coordination.
5.5.9 Polarization measurement
5.5.9.1 Polarization pattern measurement
Measurements related to polarization are generally completed in free space. 5.5.9.1.1 The antenna to be tested is in the transmitting state. The linear polarization detection antenna is rotated in a plane perpendicular to the incident direction. The polarization pattern can be obtained by recording the relationship between the relative voltage /U| of the detection antenna receiving signal and the rotation angle of the detection antenna. An example of the polarization pattern is shown in Figure 3. The major axis and minor axis of the polarization ellipse can be obtained from the polarization pattern, and the axial ratio and inclination angle t of the incident wave can be determined from it.3 Measurement of circular polarization and elliptically polarized antenna gain. For shipboard non-linear polarization communication antennas, a linear polarization standard gain antenna and a linear polarization auxiliary antenna with relatively high polarization purity can be used to measure the elliptically polarized antenna gain. The configuration block diagram for measurement is the same as Figure 2. Use the precision variable attenuator reading. If the standard gain antenna is aligned with the auxiliary antenna, the reading of the precision variable attenuator is As; connect the elliptically polarized antenna and maintain the same indication level as the standard gain antenna, and the reading of the precision variable attenuator is Ax1; rotate the polarization of the linear polarization auxiliary antenna by 90°, and the reading of the precision variable attenuator is Ax2 at the same indication level as the above. The gain of the elliptically polarized antenna to be measured is obtained by formula (8):
Gx = Gs + Ax - As +10 X Ig(1 + 10% If the antenna to be measured is a circularly polarized antenna, formula (8) can be simplified to Gx = Gs + Axi - As + 3
In formulas (8) and (9): Gx
Gain of the antenna to be measured, dB;
GsGain of the standard gain antenna, dB;
AsThe reading of the variable attenuator when connected to the standard gain antenna, dB; Ax1—The reading of the variable attenuator when connected to the elliptically polarized antenna, dB; Ax2
5.5.7.3 Measurement error
The reading of the variable attenuator after the auxiliary antenna is rotated 90°, dB. (8)
5.5.7.3.1 Main error factors||t t||In addition to the main errors in gain measurement caused by the instrument itself, feeder loss and limited measurement distance, impedance mismatch and polarization mismatch will also introduce measurement errors, which should be corrected when necessary. 5.5.7.3.2 Impedance mismatch error
When measuring antenna gain by comparison method, the impedance mismatch between the signal source and the connected antenna, and between the receiver and the connected antenna can be corrected by adding correction items.
When the antenna to be measured is used as a receiving antenna, the actual measured gain is calculated according to formula (10): +10×lgM
Gx=Gs+ 10 ×lg
（10)
Wherein: Gx
gain of the antenna to be tested, dB;
gain of the antenna with standard gain, dB;
-received power of the antenna to be tested, mW;
Ps-received power of the antenna with standard gain, mW; Mrx-impedance mismatch correction factor of the antenna to be tested; Mrs-impedance mismatch correction factor of the antenna with standard gain. Mrx and Mrs are obtained from formulas (11) and (12): Mrx
(1-x)(1 -(1)
（11)
CB133898
(1-(1 -)
In formulas (11) and (12): rx—reflection coefficient of the antenna to be measured; Ts—reflection coefficient of the standard gain antenna;
T—reflection coefficient of the receiver.
5.5.7.3.3
3 Polarization mismatch error
When measuring, the polarization mismatch of the transmitting and receiving antennas makes the measured gain greater or less than the actual value. It is necessary to introduce polarization efficiency to correct the measured gain.
When measuring antenna gain using the comparison method, if polarization mismatch needs to be considered, use the antenna to be measured as the receiver. Taking the receiving antenna as an example, the gain of the antenna to be tested can be corrected to formula (13):
+10×lg
Gx=Gs+10×lg
Wherein: Gx is the gain of the antenna to be tested, dB; Gs is the gain of the standard gain antenna, dB;
is the received power of the antenna to be tested, mW;
is the received power of the standard gain antenna, mW;
is the polarization efficiency of the incident wave of the standard gain antenna; s
7x is the polarization efficiency of the incident wave of the antenna to be tested. 5.5.8 Measurement of power capacity
(13)
In view of the wide variety of antenna structures and working environment conditions, this standard does not specify the specific measurement steps of power capacity, but only proposes the following measurement requirements.
5.5.8.1 Working environment simulation
The environmental conditions during the power capacity measurement should be the same as those during the actual operation of the antenna. If some environmental conditions such as temperature and humidity do not meet the requirements, they must be simulated. The measurement should be carried out in an appropriate simulation environment. 5.5.8.2 Power source for measurement
The performance parameters of the power source for measurement, such as modulation, pulse width, pulse waveform, pulse repetition frequency, etc., should be the same as the parameters of the transmitter used for the actual operation of the antenna, and these parameters should not change during the measurement due to different applied power levels. 5.5.8.3 Preparation before measurement
Before measurement, the antenna to be measured and its accessories should be inspected to remove possible burrs, dirt, metal debris, water film, rust, etc. 5.5.8.4 Monitoring and Observation
During measurement, instruments or personnel should be used to directly observe whether the temperature rise of the relevant dielectric or metal key parts of the antenna is within the allowable range within the specified time after the rated power is applied, and whether there is arcing, corona discharge or breakdown in various parts of the antenna. During measurement, necessary safety measures should be taken to prevent test personnel from being injured. 5.5.8.5 Alternative method
When the above conditions are not met, the power capacity performance can be evaluated by measuring the RF voltage and RF current in combination with system coordination.
5.5.9 Polarization measurement
5.5.9.1 Polarization pattern measurement
Measurements related to polarization are generally completed in free space. 5.5.9.1.1 The antenna to be tested is in the transmitting state. The linear polarization detection antenna is rotated in a plane perpendicular to the incident direction. The polarization pattern can be obtained by recording the relationship between the relative voltage /U| of the detection antenna receiving signal and the rotation angle of the detection antenna. An example of the polarization pattern is shown in Figure 3. The major axis and minor axis of the polarization ellipse can be obtained from the polarization pattern, and the axial ratio and inclination angle t of the incident wave can be determined from it.8 Measurement of power capacity
(13)
In view of the wide variety of antenna structures and working environment conditions, this standard does not specify the specific measurement steps of power capacity, but only proposes the following measurement requirements.
5.5.8.1 Working environment simulation
The environmental conditions during power capacity measurement should be the same as those during the actual operation of the antenna. If some environmental conditions such as temperature and humidity do not meet the requirements, they must be simulated. The measurement should be carried out in an appropriate simulation environment. 5.5.8.2 Power source for measurement
The performance parameters of the power source for measurement, such as modulation, pulse width, pulse waveform, pulse repetition frequency, etc., should be the same as those of the transmitter used for the actual operation of the antenna, and these parameters should not change during the measurement due to different applied power levels. 5.5.8.3 Preparation before measurement
Before measurement, the antenna to be measured and its accessories should be inspected to remove any burrs, dirt, metal debris, water film, rust, etc. 5.5.8.4 Monitoring and Observation
During measurement, instruments or personnel should be used to directly observe whether the temperature rise of the relevant dielectric or metal key parts of the antenna is within the allowable range within the specified time after the rated power is applied, and whether there is arcing, corona discharge or breakdown in various parts of the antenna. During measurement, necessary safety measures should be taken to prevent test personnel from being injured. 5.5.8.5 Alternative method
When the above conditions are not met, the power capacity performance can be evaluated by measuring the RF voltage and RF current in combination with system coordination.
5.5.9 Polarization measurement
5.5.9.1 Polarization pattern measurement
Measurements related to polarization are generally completed in free space. 5.5.9.1.1 The antenna to be tested is in the transmitting state. The linear polarization detection antenna is rotated in a plane perpendicular to the incident direction. The polarization pattern can be obtained by recording the relationship between the relative voltage /U| of the detection antenna receiving signal and the rotation angle of the detection antenna. An example of the polarization pattern is shown in Figure 3. The major axis and minor axis of the polarization ellipse can be obtained from the polarization pattern, and the axial ratio and inclination angle t of the incident wave can be determined from it.8 Measurement of power capacity
(13)
In view of the wide variety of antenna structures and working environment conditions, this standard does not specify the specific measurement steps of power capacity, but only proposes the following measurement requirements.
5.5.8.1 Working environment simulation
The environmental conditions during power capacity measurement should be the same as those during the actual operation of the antenna. If some environmental conditions such as temperature and humidity do not meet the requirements, they must be simulated. The measurement should be carried out in an appropriate simulation environment. 5.5.8.2 Power source for measurement
The performance parameters of the power source for measurement, such as modulation, pulse width, pulse waveform, pulse repetition frequency, etc., should be the same as those of the transmitter used for the actual operation of the antenna, and these parameters should not change during the measurement due to different applied power levels. 5.5.8.3 Preparation before measurement
Before measurement, the antenna to be measured and its accessories should be inspected to remove any burrs, dirt, metal debris, water film, rust, etc. 5.5.8.4 Monitoring and Observation
During measurement, instruments or personnel should be used to directly observe whether the temperature rise of the relevant dielectric or metal key parts of the antenna is within the allowable range within the specified time after the rated power is applied, and whether there is arcing, corona discharge or breakdown in various parts of the antenna. During measurement, necessary safety measures should be taken to prevent test personnel from being injured. 5.5.8.5 Alternative method
When the above conditions are not met, the power capacity performance can be evaluated by measuring the RF voltage and RF current in combination with system coordination.
5.5.9 Polarization measurement
5.5.9.1 Polarization pattern measurement
Measurements related to polarization are generally completed in free space. 5.5.9.1.1 The antenna to be tested is in the transmitting state. The linear polarization detection antenna is rotated in a plane perpendicular to the incident direction. The polarization pattern can be obtained by recording the relationship between the relative voltage /U| of the detection antenna receiving signal and the rotation angle of the detection antenna. An example of the polarization pattern is shown in Figure 3. The major axis and minor axis of the polarization ellipse can be obtained from the polarization pattern, and the axial ratio and inclination angle t of the incident wave can be determined from it.
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