(Invited) A High-Power Handling Tunable Low-Pass Filter Using Switched Capacitor in 0.5 μm GaN-on-Silicon HEMT

Abstract

A tunable low-pass filter (LPF) is developed and fabricated in 0.5 μm GaN-on-Si HEMT process. By using HEMT device to be a switch, the shunt-type switched capacitors can be presented. The performances of switching low/high capacitance ratio and power handling can be also determined with a proper arrangement of capacitors and HEMT device size. The on-chip spiral inductors are used for designing a compact 3-order LC low-pass filter. The 3-dB bandwidth of the filter is ranging from 3 GHz to 7 GHz by varying the gate bias from 0 V to -6 V. The low frequency insertion loss is 0.4 dB. The measured power handling performance is up to 36 dBm at 2 GHz under on-wafer testing.