B5. Ultra wideband patch antenna and power amplifier transmitter front end

An ultra wideband (UWB) transmitter front end (RFE) consisting of UWB circular patch antenna and an UWB GaAs common source (CS) power amplifier (PA) for the frequency range 3 to 10 GHz is presented. The patch antenna covers most of the UWB range and has an area of 30×30 squared mm. The UWB patch antenna has a return loss below 10 dB from 3 to 9 GHz, simulated with a port of 50 Ohm impedance. Since the PA and antenna both have variable impedance, the matching is performed simultaneously. The antenna impedance is directly matched to the PA using optimization algorithms. The transmitted power from the antenna is simulated with a variation around 2 dB over the entire frequency range. The PA has a gain varying from 15 to 30 dB to compensate for the antenna impedance variation.