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Standard SJ3218-89 of the Ministry of Machinery and Electronics Industry of the People's Republic of China
Ground radar receiving system
General technical conditions
Published on February 10, 1989
Implemented on March 1, 1989
Approved by the Ministry of Machinery and Electronics Industry of the People's Republic of China Standard of the Ministry of Machinery and Electronics Industry of the People's Republic of China Ground radar receiving system
General technical conditions
1 Subject content and scope of application
SJ3218-89
This standard specifies the technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of ground radar receiving systems (hereinafter referred to as receiving systems). This standard applies to ground radar superheterodyne receiving systems; other types of receiving systems should also be implemented as a reference. 2 Reference standards ||tt ||GB3784 Radar Terminology
GJB74.2 General Technical Conditions for Military Ground Radars Common Terminology GJB74.5 General Technical Conditions for Military Ground Radars Design and Manufacturing Requirements General Technical Conditions for Military Ground Radars Environmental Conditions Requirements and Test Methods GJB74.6
General Technical Conditions for Military Ground Radars Acceptance Rules GJB74.14 General Technical Conditions for Military Ground Radars: Marking, Packaging, Transportation, Storage GJB151
GJB152
3 Terminology
Requirements for electromagnetic emission and sensitivity of military equipment and subsystems Measurement of electromagnetic emission and sensitivity of military equipment and subsystems Any other related terms not defined in this standard shall be subject to GB3784 and GJB74.2. 3.1 Ground radar
Refers to fixed, semi-fixed , mobile, portable and other methods of use and working on the ground. Ground radars include: air intelligence radars, gun aiming radars, ground artillery radars, battlefield reconnaissance radars, weather radars, measurement radars, early warning radars, etc.
3.2 Ground radar receiving system
refers to all equipment that amplifies, converts, processes and monitors radar signals from high-frequency input to detection (or coherent detection) and video output (analog signal or digital signal). The ground radar receiving system is generally composed of a high-frequency amplifier, a mixer, a local oscillator, an intermediate frequency amplifier, a detector (or coherent detector), a video amplifier, and anti-interference circuits, auxiliary circuits, monitoring circuits, etc. 3.3 Noise coefficient
refers to the ratio of the power signal-to-noise ratio at the input end of the receiving system to the power signal-to-noise ratio at the output end. Ministry of Machinery and Electronics Industry of the People's Republic of China 1989 -02-10 approved for implementation on March 1, 1989
3.4 Sensitivity
SJ3218-89
refers to the minimum signal power (Ps) at the input end of the receiving system when the signal-to-noise ratio at the detection output end of the receiving system is equal to 1. The conversion formula of power sensitivity and noise coefficient is: P.-K.ToB.F..D
where: D is the identification coefficient, generally D=1;
Ps is the power sensitivity of the receiving system, W;
F. The noise coefficient of the receiving system (should be converted to a constant) standard room temperature, 290K;
K--Bohr-Mann constant, 1.38×10-29J/K; B. The passband of the receiving system, Hz.
3.5 Image frequency interference suppression
refers to the ratio of the signal frequency response to the image frequency response. 3.6 Combined interference
The combination of the fundamental wave and harmonics of each oscillation source inside the radar forms interference to the receiving system. 3.7 Instantaneous frequency stability
refers to the relative change of the frequency source frequency within a specified time (generally less than 10ms). 3.8 The noise level and level drift of the detector output refer to the DC level (noise level) and level drift of the detector output when there is no signal input. 3.9 Dynamic range
refers to the ratio of the input signal power (or voltage value) to the minimum detectable input signal power (or voltage value) at the 1dB compression point of the receiving system gain.
4 Technical requirements
4.1 General requirements
4.1.1 Appearance and structure
The surface should not have obvious dents, scratches, cracks, deformation and other phenomena: the surface coating should not bubble, crack and fall off; the metal parts should not have rust and other mechanical damage, the operation of switches, knobs, buttons, etc. should be flexible and convenient; the parts should be tightened without looseness, and the text symbols and signs indicating the functions should be clear and correct. 4.1.2 Reduction
Components or units that are easily affected by lightning in structure or electrical performance should have necessary shock absorption measures. 4.1.3 Safety
The safety design should comply with the provisions of Article 1.9 of GJB74.5, and the operating procedures should be simple and reasonable to ensure the safety of people and equipment; dangerous parts should have warning signs or safety protection devices installed in obvious places.
4.1.4 Performance monitoring
The receiving system should have monitoring devices for the main performance parameters. Such as: "Local oscillator working status", "noise level", "noise coefficient", "working voltage", "working current" and other monitoring devices. 4.1.5 Fault monitoring
The receiving system should have fault diagnosis, "isolation and positioning fault monitoring devices. 4.1.6 Interface
The input and output impedance of the receiving system is generally 502 or 750. The input and output signal form, amplitude, connectors and cables used should comply with the provisions of the whole machine. The form and amplitude of various input control signals should comply with the provisions of the whole machine. For receiving systems with computer monitoring, corresponding interface circuits should be provided. 4.1.7 Auxiliary circuit
If necessary, frequency fine-tuning circuits, various gain control circuits and various expansion circuits can be installed in the receiving system. Interference circuit, etc.
4.1.8 Power adaptability
When the frequency tolerance of the AC power supply is within 6% and the voltage changes by 10%, the receiving system should be able to work normally 4.1.9 Insulation
The receiving system must have good electrical insulation to ensure the safety and reliability of the product. The insulation resistance between the circuit and the casing shall comply with the provisions of Table 1.
Table 1 Insulation resistance
Test conditions
Pure insulation type
Normal insulation
High insulation
4.2 Main technical performance
4.2.1 Noise coefficient or sensitivity
Specified by product standards
4.2.2 Gain
Specified by product standards,
4.2.3 Intermediate frequency and bandwidth||tt ||Specified by product standards,
4.2.4 Image frequency interference suppression
Specified by product standards.
4.2.5 Combined interference suppression capability
Specified by product standards.
4.2.6 Local oscillator frequency range
Specified by product standards,
4.2.7 Local oscillator output power
Specified by product standards,
Normal test atmospheric conditions
50~1000
Not less than 1000
After constant humidity and heat test
Not less than 100
4.2.8 Local oscillator instantaneous frequency stability
Specified by product standards.
SJ3218-89
4.2.9 IF detector output noise The level and level drift are specified by the product standard,
4.2.10 Video amplifier gain and bandwidth
are specified by the product standard,
4.2.11 Dynamic range
are specified by the product standard,
4.2.12 Input end power withstand requirements
are specified by the product standard,
4.3 Environmental condition requirements
4.3.1 High temperature
4.3.1.1 The high temperature environmental condition requirements for the receiving system should be selected from Table 2 based on the specific conditions of each type of radar during transportation, storage and use:
Table 2 High temperature environmental condition requirements
Place of use
Working temperature
4.3.1.2 High temperature working time and high temperature storage time are specified by the product standard. 4.3.2 Low temperature
Storage temperature
4.3.2.1 The requirements for low temperature environment conditions of the receiving system should be selected from Table 3 according to the specific conditions of each type during transportation, storage and use:
Place of use
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Table 3 Requirements for low temperature environment conditions
Working temperature
0,-10,-20
-35，-40,-45
Low temperature working time and low temperature storage time are specified by the product standard. 4.3.3 Constant damp heat
Storage temperature
--40，-45，-50
4.3.3.1 The requirements for constant humid heat environmental conditions of the receiving system shall be selected from Table 4 according to the specific conditions of each type of radar during transportation, storage and use:
Table 4 Requirements for constant condensing heat environmental conditions
Place of use
Relative humidity
4.3.3.2 Test duration and recovery time shall be specified by the product standard 3.3.4 Shock
Ambient temperature
30, 35
The requirements for shock environmental conditions of the receiving system shall be selected from the provisions of 8.1.1 to 8.1.3 of GJB74.6 according to the different loading methods of each type of radar and the specific conditions of artillery shock, mechanical shock, magnetic collision, etc. during transportation, marching and use
4.3.5 Vibration
The requirements for vibration environmental conditions of the receiving system shall be selected from Table 10 and Figure 7 of GJB74.6 according to the different loading methods of each type of radar.
4.4 Reliability and maintainability requirements
4.4.1 Reliability
The mean time between failures (MTBF) of the receiving system shall be specified by the product standard. 4.4.2 Maintainability
The mean time to repair (MTTR) of the receiving system shall be specified by the product standard. 4.5 Electromagnetic compatibility requirements
Electromagnetic compatibility requirements shall comply with the relevant provisions of GJB151. 5 Test methods
5.1 General requirements test
5.1.1 For the requirements of 4.1.1 to 4.1.8 of this standard, the specific inspection or measurement methods shall be specified by the product standard. 5.1.2 Insulation test
. Test conditions: normal test atmosphere and fixed mixed heat test: b. Measuring instrument: 500+100V, 1.0-level megohmmeter; c. Insulation resistance inspection location: between power input terminal and housing; between circuit with insulation requirements and housing; between external live ports with insulation requirements (such as wiring board, plug socket, etc.) and housing. d. Test results should meet the requirements of Article 4.1.9. 5.2 Main technical performance tests
5.2.1 Noise coefficient or sensitivity
The test method for noise coefficient shall be carried out in accordance with A in Appendix A (Supplement); the test method for sensitivity shall be specified by the product standard; the test results shall comply with the provisions of Article 4.2.1.5.2.2 Gain
The test method shall be carried out in accordance with A2 in Appendix A (Supplement); the test results shall comply with the provisions of Article 4.2.2.5.2.3 Intermediate frequency and bandwidth
The test method shall be carried out in accordance with A3 in Appendix A (Supplement); the test results shall comply with the provisions of Article 4.2.3. 5.2.4 Image frequency interference suppression
The test method shall be specified by the product standard;
The test results shall comply with the provisions of Article 4.2.4. 5.2.5 Combined interference suppression capability
Test method shall be specified by the product standard;
Test results shall comply with the provisions of Article 4.2.5. 5.2.6 Local oscillator frequency range
Test method shall be carried out in accordance with A4 in Appendix A (Supplement); Test results shall comply with the provisions of Article 4.2.6. 5.2.7 Local oscillator output power
Test method shall be carried out in accordance with A5 in Appendix A (Supplement); Test results shall comply with the provisions of Article 4.2.7. 5.2.8 Local oscillator instantaneous frequency stability
Test results shall be carried out in accordance with A6 in Appendix A (Supplement); Test results shall comply with the provisions of Article 4.2.8. 5.2.9: The test method for the noise level and level drift of the intermediate-frequency detection output shall be carried out in accordance with Appendix A (A2 in the supplementary material): The test results shall comply with the provisions of Article 4.2.9. 5.2.10 The test method for video amplifier gain and bandwidth shall be specified by the product standard; the test results shall comply with the provisions of Article 4.2.10. 5.2.11 The test method for dynamic range shall be specified by the product standard; the test results shall comply with the provisions of Article 4.2.11. 5.2.12 The power withstand requirements at the input end shall be specified by the product standard; the test results shall comply with the provisions of Article 4.2.12. 5.3 Test method for environmental conditions |General requirements for environmental condition tests shall be carried out in accordance with the relevant provisions of Articles 3.1 to 3.7 of GJB74.6. 5.3.1 High temperature test
5.3.1.1 High temperature working test and high temperature storage test can be carried out separately or in combination; their temperature change curves shall be selected from Figures 1 to 3 of GJB74.6. 5.3.1.2 High temperature test equipment and methods shall be carried out in accordance with the provisions of Articles 4.2.3 to 4.2.7 of GJB74.6. 5.3.1.3 The initial, intermediate and final test items during the high temperature test shall be specified by the product standards. 5.3.1.4 The test results shall comply with the provisions of Article 4.3.1. 5.3.2 Low temperature test
5.3.2.1 Low temperature working test and low temperature storage test can be carried out separately or in combination. Conducted jointly; its temperature change curve is selected from Figures 4 to 6 in GJB74.6. 5.3.2.2 Low temperature test equipment and methods shall be in accordance with the provisions of Articles 7.2.3 to 7.2.7 of GJB74.6. The initial, intermediate and final test items during the low temperature test shall be specified by the product standard. 5.3.2.3
5.3.2.4 The test results shall comply with the provisions of Article 4.3.2. 5.3.3 Constant humidity and heat test
The constant humidity and heat test equipment and methods shall be in accordance with the provisions of Articles 6.2.3 to 6.2.5 of GJB74.6. 5.3.3.2
The initial, intermediate and final test items and recovery time during the constant heat test shall be specified by the product standard.
The test results shall comply with Article 4.3.3 5.3.4 Impact test
5.3.4.1 Impact test shall be carried out in accordance with the relevant provisions of Article 8.2 of GJB74.6. The initial and final test items during the impact test shall be specified by the product standard. 5.3.4.2
5.3.4.3 The test results shall comply with the provisions of Article 4.3.4. 5.3.5 Vibration test
5.3.5.1 Vibration test shall be carried out in accordance with the relevant provisions of Article 9.2 of GJB74.6. 5.3.5.2 The initial and final test items during the vibration test shall be specified by the product standard. 5.3.5.3 The test results shall comply with the provisions of Article 4.3.5. 5.4 Reliability and maintainability test methods
5.4.1 Reliability test
Specified by the product standard.
5.4.2 Maintainability test
Specified by product standards,
5.5 Electromagnetic compatibility test
SJ3218-89
Electromagnetic compatibility test shall be carried out in accordance with the relevant methods specified in GJB152. 6 Inspection rules
6.1 Inspection classification
The receiving system inspection is divided into: a. Finalization inspection; b. Acceptance inspection; c. Routine inspection.
6.2 Inspection items
All kinds of inspections are generally carried out according to the items and requirements listed in Table 5. 6.3 Implementation of inspection
6.3.1 Finalization inspection
6.3.1.1 Timing
When the product is finalized in design or production, it shall pass the finalization inspection. 6.3.1.2 Sampling
Not less than one unit.
Inspection items
Inspection items
General requirements
Main technical performance
Constant damp heat
Reliability, maintainability
Electromagnetic compatibility
Type inspection
Note: (1)\\ indicates a required item;
(2)*O\ indicates an optional item
6.3.1.3 Determination of pass and fail
Delivery inspection
Routine inspection
Technical requirements
4.1.1~4.1. 9 Articles
4.2.1~4.2.12 Articles
Test methods
5.1.1~5.1.2 Articles
5.2.1~5.2.12 Articles
After inspection, if all the final inspection items meet the specified requirements, they will be judged as qualified; if any one of them does not meet the specified requirements, it will be judged as unqualified. 6.3.1.4 Re-inspection
Unqualified products should be returned to the production department, the defects should be eliminated, and after necessary adjustment, they can be resubmitted for inspection until they are qualified.
6.3.2 Delivery inspection
6.3.2.1 Timing
SJ3218—89
In batch production, in principle, it should be carried out once for each order batch. 6.3.2.2 Sampling
100% inspection is implemented.
6.3.2.3 Determination of qualified and unqualified
Same as Article 6.3.1.3,
6.3.2.4 Re-inspection
Unqualified products should be returned to the production department, and the defects should be eliminated. After necessary adjustment, they can be resubmitted for inspection.
6.3.3 Routine inspection
6.3.3.1 Timing
Routine inspection is carried out once for each order batch in principle; when the order batch is less than 5 units, the two parties can agree on it separately.
6.3.3.2 Sampling
For routine inspection, random sampling shall be conducted among the qualified products (not less than 5 units) after delivery inspection. When the batch is less than or equal to 5 units, the sampling number shall be 1 unit; when the batch is greater than 5 units, the sampling number shall be 2 to 3 units. 6.3.3.3 Determination of qualified and unqualified
After inspection, if all items meet the specified requirements, it shall be judged as qualified; if one item is found to be unqualified, it shall be judged as unqualified.
6.3.3.4 Re-inspection
Products that fail routine inspection shall be returned to the production department to find out the reasons for the failure, and take effective measures for all products. After eliminating the defects, re-sampling according to Article 6.3.3.2 can be carried out for the second inspection. When re-inspecting the routine test, the test items not related to the unqualified items may not be inspected again. 6.3.3.5 Sample processing
The samples of routine inspection can be delivered as a whole frame or shipped out of the factory as qualified products after inspection, repair, debugging and re-submission for acceptance inspection.
When there are special requirements for the handling of samples that have undergone routine inspection, they should be clearly stipulated in the product order contract. 7 Marking, packaging, transportation, storage
7.1 Delivery of whole frame
The receiving system extensions that have passed the inspection and are hung with a certificate of conformity should be protected from shock, rain, moisture, dust, magnetism and be handled with care during the transportation process of being sent to the whole frame debugging site for whole machine joint testing. 7.2 Individual ordering
The marking, packaging, transportation and storage of the receiving system extensions ordered separately shall be carried out in accordance with the provisions of GJ74.14.
SJ3218--89
Appendix A
Test methods for main technical performance of ground radar receiving system (supplement)
A1 Noise coefficient test method
A1.1 Description
The test of receiver noise coefficient usually adopts the Y coefficient method. The common formula is: F=ENR-101g(Y-1)..
Y Po +Pno.
Noise coefficient of receiving system expressed in decibels: Where F
ENR-excess noise ratio given by the noise generator, dB; PN. ———The power at the output end of the receiving system when the noise generator has no output; Pso—The power at the output end of the receiving system when the noise generator has output. (An)
·(A2)
YThe multiple of the output power of the receiving system when the noise generator has output power compared with no output power.
A1.2 Block Diagram
The test block diagram is shown in Figure A1 and A2.
Generator
Note: The receiving system under test is in the dotted box in the figure. —10-
Front intermediate amplifier
Intermediate amplifier subtractor
Intermediate amplifier, detector
and electric phlegm
Cold-hot load
Standard sound source
Note: The receiving system under test is in the dotted box. A1.3 Test instrument
2. Saturated diode noise generator:
b. Gas discharge tube noise generator;
e. Solid-state noise generator:
d. Standard noise generator for cold and hot loads;Www.bzxZ.net
SJ3218-89
Front center amplifier
Precision intermediate frequency step attenuator (step interval is 0.1dB)e.
A1.4 Test method
A1.4.1 Power doubling method (when coefficient Y=2)Precision intermediate frequency step attenuator
Intermediate frequency amplifier, detector
and electric meter
This method is suitable for the receiving system in meter wave and decimeter wave bands. At this time, a saturated diode beam sound generator is generally used, and its output super-noise ratio can be adjusted.
a. Connect as shown in Figure A1;
b. Do not start the noise generator, the output of the receiving system indicates P (power value); c. Start the noise generator and adjust its output size so that the output of the receiving system indicates P (power value) and P,/P,=2;
d. Or turn on the switch to position 2 and connect the intermediate frequency attenuator to make the attenuation amount 3dB; start the noise generator and adjust its output size so that the output of the receiving system still indicates Wei, value e. In both cases of "c\\d\", the noise coefficient of the receiving system is: F (dB) = ENR (dB) A1.4.2 Intermediate frequency attenuation method (- generally refers to the case of Y丰2) In the microwave band, this method is suitable. At this time, a gas discharge tube noise generator or a solid-state noise generator is used. The output super-noise ratio is fixed. Generally, a precision intermediate frequency attenuator is inserted between the front intermediate amplifier and the main intermediate amplifier of the receiving system for testing.
2. Connect according to Figure A1, and connect the switch to position 2; -11-Solid-state noise generator:
d. Cold and hot load standard noise generator;
SJ3218-89
Front center amplifier
Precision intermediate frequency step attenuator (step interval is 0.1dB) e.
A1.4 Test method
A1.4.1 Power doubling method (coefficient Y=2) Precision intermediate frequency step attenuator
Intermediate amplifier, detector
and electric meter
This method is suitable for the receiving system of meter wave and decimeter wave band. At this time, a saturated diode beam sound generator is generally used, and its output super noise ratio can be adjusted.
a. Connect according to Figure A1;
b. Do not start the noise generator, the output of the receiving system indicates P (power value); c. Start the noise generator and adjust its output size so that the output of the receiving system indicates P (power value) and P,/P,=2;
d. Or turn on the switch to position 2 and connect the intermediate frequency attenuator to make the attenuation amount 3dB; start the noise generator and adjust its output size so that the output of the receiving system still indicates Wei, value e. In both cases of "c\\d\", the noise coefficient of the receiving system is: F (dB) = ENR (dB) A1.4.2 Intermediate frequency attenuation method (- generally refers to the case of Y丰2) In the microwave band, this method is suitable. At this time, a gas discharge tube noise generator or a solid-state noise generator is used. The output super-noise ratio is fixed. Generally, a precision intermediate frequency attenuator is inserted between the front intermediate amplifier and the main intermediate amplifier of the receiving system for testing.
2. Connect according to Figure A1, and connect the switch to position 2; -11-Solid-state noise generator:
d. Cold and hot load standard noise generator;
SJ3218-89
Front center amplifier
Precision intermediate frequency step attenuator (step interval is 0.1dB) e.
A1.4 Test method
A1.4.1 Power doubling method (coefficient Y=2) Precision intermediate frequency step attenuator
Intermediate amplifier, detector
and electric meter
This method is suitable for the receiving system of meter wave and decimeter wave band. At this time, a saturated diode beam sound generator is generally used, and its output super noise ratio can be adjusted.
a. Connect according to Figure A1;
b. Do not start the noise generator, the output of the receiving system indicates P (power value); c. Start the noise generator and adjust its output size so that the output of the receiving system indicates P (power value) and P,/P,=2;
d. Or turn on the switch to position 2 and connect the intermediate frequency attenuator to make the attenuation amount 3dB; start the noise generator and adjust its output size so that the output of the receiving system still indicates Wei, value e. In both cases of "c\\d\", the noise coefficient of the receiving system is: F (dB) = ENR (dB) A1.4.2 Intermediate frequency attenuation method (- generally refers to the case of Y丰2) In the microwave band, this method is suitable. At this time, a gas discharge tube noise generator or a solid-state noise generator is used. The output super-noise ratio is fixed. Generally, a precision intermediate frequency attenuator is inserted between the front intermediate amplifier and the main intermediate amplifier of the receiving system for testing.
2. Connect according to Figure A1, and connect the switch to position 2; -11-
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