Impedance-matched planar-antenna-integrated high-efficiency push-pull power amplifier with center-tapped transformer for 5 GHz wireless communication

We present a highly efficient power amplifier (PA) with an impedance-matched planar antenna. An impedance-matching network including inductors and capacitors is a common and essential practice for wireless communication systems; however, efficiency degradation at a matching network is a serious issue. We implement a matching block into a planar antenna and integrate a PA with the impedance-matched planar antenna. The impedance-matched antenna and PA are applied to a wireless transmitter for the 5 GHz band in a 0.18 mm CMOS. The proposed integrated PA has a power-added efficiency (PAE) of 15.7% in linear operation and a maximum PAE of 30.7%.