A 3-stage 40 GHz CMOS power amplifier driver for radio-over-fiber technology

A 40 GHz power amplifier (PA) driver for the remote antenna unit (RAU) transceiver of a mm-wave radio-over-fiber (RoF) system is presented in this paper. Mm-wave RAU is proposed as a complementary technology to fiber-to-the-home to minimize costs and to increase bandwidth. In order for RoF to be feasible, the cost of the RAU must be minimized through low-cost technology such as CMOS. The PA driver is designed using a 0.13μm RF CMOS process. The architecture used is a 3-stage, double-cascode amplifier. It has input and output reflection coefficients that are better than -10 dB over a bandwidth of 7 GHz. Maximum gain is 33.6 dB and output P1dB is 7.6 dBm. This is the first reported use of a three-stage, double-cascode, 130nm CMOS amplifier for the implementation of a 40 GHz radio-over-fiber system.