A 130nm CMOS power amplifier driver for a 40 GHz radio-over-fiber system

A 40 GHz power amplifier (PA) driver for the remote antenna unit (RAU) transceiver of a radio-over-fiber (RoF) system is presented in this paper. RoF is proposed as a complementary solution to fiber-to-the-home (FTTH) in order to minimize costs as well as ease accessibility. CMOS is proposed as a low cost technology for implementing the RF portion of the RAU. The PA driver is designed using a 0.13um CMOS process and the architecture used is common-gate and utilizes 50 Ohm transmission lines and metal-finger capacitors. Measurements show that the PA driver has input and output reflection coefficients that are lower than -10 dB for frequencies between 40 and 42.5 GHz. Gain is 2.1 dB and output P1dB is 10.9 dBm. The PA driver is unconditionally stable for frequencies over 4.66 GHz up to 50 GHz.