InGaP/GaAs HBT power amplifier based on flexible printed circuit board

This paper presents InGaP/GaAs hetero-junction bipolar transistor (HBT) power amplifier based on flexible printed circuit board (FPCB) for 5.2 GHz band. FPCB is suitable to fabricate light weigh and small size modules with the help of its thin thickness. Moreover a module based on FPCB can be attached on the arbitrary curved surface by its flexible enough to be rolled up like paper. But, the conventional FPCB such as kapton based FPCB shows very high loss characteristic and it is not profitably employed for the frequency band over several tens or hundreds MHz. In this paper, we proposed the power amplifier integrated on FPCB for a short-distance sensor network which is based on orthogonal frequency division multiplexing (OFDM) communication system. The proposed power amplifier is fabricated on InGaP/GaAs HBT process which has been used for power amplifier design to take advantages of high linear and high efficient characteristics. The measured result of the proposed amplifiers shows gain of 25 dB and output power of 17 dBm.