Very Linear X-band Mic Bipolar VCO With 100mhz FM Rate

This paper describes a microstrip, doubling mode bipolar transistor oscillator (osciplier), varactor tunable over 8- 10GHz with an output power of 12dBm/spl plusmn/1dB. It has an FM rate of 100MHz with a set-on accuracy of /spl plusmn/8MHz from perfect linearity (i.e. /spl plusmn/0.1%)and frequency pulling /spl plusmn/1MHz into a 2:1 mismatched load. Power flatness and frequency pulling immunity is achieved using a two stage GaAS FET buffer/limiter. It maintains these specifications over a temperature range of -54/spl degree/C to 100/spl degree/C.