Abstract
A 1.8 GHz broadband high power amplifier (PA) with 144% fractional bandwidth is presented in this article. The proposed PA achieves a power added efficiency of 40%-56% for the entire band. To ensure flat gain response, a novel idea of integrating a microstrip high pass filter (HPF) in the input matching network is proposed. The incorporation of HPF reduces the unusual high gain at low frequency and thus results in a flat gain of 14.4 +/- 1 dB for the entire band. The matching circuits are realized on Taconic RF35 with dielectric constant of 3.5 and thickness of 0.76 mm. The high fractional bandwidth of the proposed PA makes it suitable to be used for the recent and future wireless communication systems.