2.2 GHz Transmission Zero Embedded, Harmonically Tuned 10 W Power Amplifier

In this paper, a highly efficient harmonically tuned (HT) power amplifier (PA) with embedded Transmission zero (TZ) is presented. The proposed matching network can simultaneously match to the optimum impedance at fundamental using just a single TLIN and suppress second and third harmonic signals. Additional shunt stubs are added, generating transmission zero at desired frequency to block unwanted signal or interference and enhancing band selectivity. For demonstration, a PA using CREE CGH40010F GaN HEMT was designed to operate at 2.2 GHz. A power added efficiency (PAE) of 74.6 % and Drain efficiency (DE) of 79.1 % was achieved, with a corresponding output power of 40.9 dBm and a highly selective small signal gain of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$13.77-17.02 ~\text{dB}$</tex> in the operating bandwidth of 200 MHz by creating a transmission zero (TZ) point out of the bandwidth. In addition, third and fifth order intermodulation distortions were also considered in analyzing the design performance. A significant improvement was observed in minimizing the distortions after the introduction of transmission zero. The design's linearity was assessed by measuring output power (38.142 dBm), PAE <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(52.96 \%)$</tex>, and DE (54.30 %) at the P1dB compression point. Furthermore, the layout of the design was also developed. The layout co-simulation results show that the PA can reach 70.6 % PAE, 75.18 % DE, and 40.88 dBm output power.