A 925-960 MHZ I Q MODULATOR IN A 8 GHZ 1.2 MU-M BICMOS PROCESS/

An integrated I/Q modulator has been implemented in a commercially ava ilable 8 GHz 1.2 mu m double metal double poly BiCMOS process. The cir cuit converts baseband signals from 60 kHz to 500 kHz directly to a ca rrier frequency which can be selected between 925 MHz and 960 MHz. It has an internal 90 degrees phase shifter for the LO signal, the phase shift of which can be adjusted automatically using a control signal ge nerated inside the circuit, The size of the circuit is 2.9 mm x 2.9 mm and it consumes about 50 mA. Measurements suggest that the specified LO suppression and image rejection of 35 dBc can be achieved under opt imal operating conditions.