A Compact Ka-Band GaAs pHEMT MMIC Notch Filtering Power Amplifier

In this paper, a compact Ka-band power amplifier (PA) with good bandstop responses from the matching network is designed for satellite communications. Compared with the conventional PA, it can suppress the undesired signal and meanwhile ensure the low loss and good performance. For demonstration, a 0.15 mu m GaAs pseudomorphic high electron mobility (pHEMT) two-stage PA based on the matching filtering technique is implemented, which exhibits the small-signal gain of 15.5 dB in the Ka-band and the suppression greater than 55 dB in the K-band, the output saturation power (P-sat) of 21 dBm and the power-added efficiency of 35% at P-sat.