电光开关驱动用吉赫兹微波信号源的研制

In this paper, a portable GHz signal source is designed and developed based on advanced RSIC machine (ARM7) processor and lock-in amplifying technique, which includes a signal generator and a signal amplifier. Simulation on microstrip line electrode is performed using high frequency structure simulator (HFSS) software, and both PCB thickness and electrode width are optimized to get an characteristic impedance of 50 Ω. After the integration of the overall system, measurements are carried out to derive the performances of the signal source. Experimental results indicate that, as the frequency increases from 0.2 to 1.5 GHz, the peak-to-peak amplitude range of the unamplified signal is 16.3~333 mV, that of the amplified signal is 0.152~4.02 V, and the gain of the developed amplifier is 17.7~22.8 dB; the output power decreases from -17.41 to -4.788 dBm, and the cutoff frequency is estimated to be about 4.6 GHz under the noise level of -55 dBm. The signal source can be utilized to supply GHz driving signals for electro-optic switches instead of the commercially avilable expensive ones due to its compact size and acceptable performances.