A 6-18 GHz push-pull power amplifier with wideband even-order distortion cancellation in LCP module

We present the development of a microwave push-pull power amplifier (PA) module that achieves both high output power and wide bandwidth 2(nd)-order harmonic cancellation from 6 GHz to 18 GHz. Measured P-1dB output power for the push-pull PA is 31 dBm, while its 2(nd)-order harmonic distortion is reduced by a minimum 20 dB throughout the 6-18 GHz passband compared to a single PA. The 2(nd)-harmonic output of the pushpull PA was also measured to be lower than -40 dBc all the way up to 36 GHz. The PA module was integrated into a liquid crystal polymer (LCP) substrate that enables the design of wide bandwidth baluns with less than 0.5 dB and 6 degrees amplitude and phase imbalances, respectively.