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영어

The device efficiency of a silicon SDR (p+nn+) IMPATT diode at Ka-band has been studied by using small signal simulation and field swing upto 50 % of the maximum dc electric field. It is found that the d.c. to r.f. conversion efficiency of the SDR IMPATT diode decreases with the increase in field swing upto 50 %, from 8.98% to 7.84%. An integrated heat sink cum resonant cap cavity has been used for Ka-band oscillator in the present simulation. RF measurements have been performed on a silicon Ka-band SDR (p+nn+) IMPATT diode embedded in the cavity. Simultaneous electronic and mechanical tuning of the oscillator has been carried out to optimize the frequency and generated r.f. power output over the operating range of input d.c. bias current. An optimized r.f. power output of 180 mW has been obtained from the oscillator with an input d.c. bias current 190 mA. The measured output power has been co-related with theoretical estimated r.f. power obtained from simulation from which the efficiency of the resonant cap oscillator has been obtained.