Design and simulation of variable active filter without inductor by using BICMOS Technology

A monolithically microwave integrated circuit (MMIC) variable active filter is presented for obtaining a small size variable bandpass filter with high selectivity at microwave frequencies. Variable active filter have been designed in BICMOS technology and used Advanced Design system (ADS) software for Design and simulation circuits. It is controllable for both quality factor Q, varying from 55 to 85, and a center frequency wider than 700MHz at the 2GHz band. Achieved Gain above 20dB from 1.65–2.35GHz. We used active input and output impedance matching. This will be a key device in the future development of frequency variable equipment.