MIL-STD-469 Radar Engineering Interface Requirements, Electromagnetic Compatibility See Notice 1 For Replacement InformationThis standard establishes the engineering interface requirements to control the electromagnetic emission and susceptibility characteristics of all new military radar equipment and systems operating between 100 megahertz MHz, and 100 gigahertz GHz, to ensure EMC in all intended operational environments, and to conserve the frequency spectrum available to military radar systems.

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MIL-STD-469B APPENDIX A

Transmitter frequency (F  ): 5000 MHz

Signal generator substitution level (P      ):    11.0 dBm

Attenuation inserted (A  ): 40.0 dB

Signal sampler coupler factor (A  ): 50.0 dB

Transmission line attenuation, signal sampler to antenna (A   ): 1.0 dB

The peak power output at the radar antenna is calculated as follows:

Pp  = PGEN  + AS  + A1      A2

=    11.0 dBm + 50.0 dB + 40.0 dB     1.0 dB

= 78.0 dBm.

40.2.5.3  Sample data forms for recording peak or average power output data are shown on figures 2 and

3.

40.3  Pulse width and rise time.

40.3.1  Objective.  The objective of this test is to determine the amplitude versus time characteristics of the RF pulse at the transmitter output.

40.3.2  Requirements.  This procedure should be used to determine pulse width and rise time whenever those values must be experimentally determined for use in other tests required by this standard.

40.3.3  Application notes.  The results from this test have a number of essential applications, as follows: (1) verifying that the pulse width is within specified equipment tolerances, (2) converting measured transmitter average power output levels to peak power output levels and (3) calculations which determine the radar emission bandwidth and emission level.

40.3.3.1  The pulse width test procedure should include any measurements that are needed for determining the radar pulse envelope, in the time domain, at the radar output. The response of the test setup and any

factors needed for relating the test point level to the antenna input level must be known.

40.3.3.2  The 3 dB bandwidth of the instrumentation used for recovering the time waveform of the pulse width and rise time should be greater than 3/t r  where tr  is the pulse rise time in microseconds. A measurement objective should be 10/t r.

40.3.3.3  The points used for determining the pulse width should be as shown on figure 4.   Rise time should be determined from the 10 to 90 percent points, relative to the nominal flat top level.

40.3.3.4  The test oscilloscope is the basic instrument for measuring the amplitude versus time characteristics of the transmitter's pulsed emission. The test procedure consists of detecting the RF pulse with a crystal detector and measuring the resultant pulse envelope with the test oscilloscope. One advantage of this method is that the oscilloscope frequency response must accommodate only the video frequencies comprising the pulse envelope rather than frequency components near the transmitter fundamental. The disadvantages are that the detector input level should approach the upper end of the detector linear dynamic range and the

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