Research and impact on the target injection power smoothing algorithm in aircraft system-level HIRF testing

The avionics system and brake system of an aircraft are critical, and their system-level HIRF test plays a key role in aircraft airworthiness certification, During the system-level Reverberation Chamber (RS) HIRF test process, the injected power value required at each frequency point during testing varies greatly, which leads to unstable output of the power amplifier and makes the actual received field strength in the reverberation chamber too high or too low, thus adversely affecting the test results. After studying and discussing the DO-160 standard and its supplementary guidance standard DO-357, it is found that the injected power smoothing algorithm can be introduced during the test to reduce the error between the actual received field strength in the reverberation chamber and the required field strength for testing. The test results show that after introducing the smoothing algorithm, the forward power curve is smoother, and the field strength obtained in the reverberation chamber is more stable, greatly reducing the situation of over-testing or under-testing, and improving the test stability.