Analysis Of Correlative Technology On Power Measurement Of High Power Microwave

Power measurement is an important part of high-power microwave measuring technology. The far field method is the main method for the power measurement. Several key factors of the far field method have been studied using theoretical analysis, numerical simulation and experimental investigation. The main aspects include the power handling capacity of BJ100 waveguide to coaxial adapter, the reflection of two kinds of wave-absorbing material in the condition of a small incidence angle and the attenuation of the BJ320 waveguide. The results have some significance for the referrence of the far field method.The detailed contents of this thesis are listed below:1. The power handling capacity of BJ100 waveguide-to-coaxial adapter in X-band is calculated by numerical simulation, to be about 87kW. In the condition of normal temperature and standard atmosphere, the microwave breakdown threshold power of the adapter is tested with different microwave pulse widths, repetition rates and duration time. The result shows that the breakdown threshold power for the adapter is about 40kW in X-band with 100ns pulse width, and the power handling capacity decreases significantly while the pulse width increases from 80ns to 230ns. While the repetition rate below 50Hz, the repetition rate and the duration time have little influence on the power handling capacity of the adapter.At last, the difference between theoretical and experimental investigation is preliminarily analyzed, and a method to increase the power handling capacity of BJ100 waveguide-to-coaxial adapter is given.2. In S-band and X-band, the transmission of the wave-absorbing artificial-grass at a vertical incident angle and the reflectation at a small incident angle are tested and analyzed.The experimental results show that the transmission of the wave-absorbing artificial-grass is about -20dB in S-band and between -20 dB and-12dB in X-band. When the incident angle increases, the reflection of the wave-absorbing artificial-grass increases in S-band and has no obvious change in X-band. In S-band, the reflection at a small incident angle of the AXB absorbing material is between -40dB and -35dB.3. The attenuation of the BJ320 waveguide in millimeter wave range is analyzed theoretically and measured experimentally. When the wave frequency varies from 30GHz to 36GHz, under the condition of normal temperature and standard atmosphere, the theoretical attenuation of BJ320 waveguide ranges from -0.52dB/m to -0.6dB/m and the experimental attenuation ranges from -1.18dB/m to -1.36dB/m. The difference between theoretical and experimental investigation is analyzed to be mismachining tolerance.