Study On Key Technology Of Measurement System For Microwave Module’s Amplitude-Frequency Characteristic

The key technology of measurement system for microwave module’s amplitude-frequency characteristic is studied in this thesis. The system, which includes an S-band frequency synthesizer and a Ka-band power detector, serves for the earth station of satellite communication system. The main jobs are listed as follows:1. An S-band frequency synthesizer is designed and measured. Through theoretical analysis and other means, the scheme that uses a DDS for driving a highly integrated PLL with VCOs inside is selected from various solutions. The DDS, PLL, VGA, coupler and detector are designed and validated separately. The phase noise of the S-band frequency synthesizer is better than-92.78dBc/Hz@1kHz and spurious signal is smaller than -60dBc. The output power ranges from -30dBm to -10dBm. At the same time, the contribution of each part for the PLL’s phase noise is discussed in detail according to the application.2. A Ka-band power detector is designed. Two kinds of Schottky diodes are used to design the detector separately. DMK2790 is a Flip-flop GaAs diode. Its three-dimensional electromagnetic simulation model of the passive part is established with consideration of the physical hierarchy and installation method.3. The design of the control board with a Freescale Cortex-M4 chip is finished and it is programmed on the IAR for ARM platform. The PC interface software is designed with MFC using C++ language. It consists of signal-control module, communication module and display module. The PC communicates with the control board by USB. It can control the S-band output frequency and power, and can also display the Ka-band power.