30 GHz Front-End with Adaptively Biased PA and Current Steering LNA for Phased Array Systems

This work presents a wideband switchless Front-End (FE) which contains a two-stage power amplifier (PA) and a two-stage low noise amplifier (LNA). The linearity of the PA is the focus of the work in the transmitter side (TX) and is improved by adopting a stacked configuration with an adaptive bias technique. The adaptive bias improves the output compression point (O1dB) by nearly 5 dBm. A driver is placed before the output stage of the PA to ensure wideband operation and higher gain. The LNA consists of two-stage single ended configurations and uses the current steering architecture to provide extended reconfigurable operation. Both LNA and PA are connected to the antenna through a passive structure called duplexer which provides optimum noise and power matching at each side with low losses and minimum area occupation. The process used for the design is TSMC’s 40nm bulk CMOS and all the simulations are post layout extracted. The design covers a 3-dB bandwidth of 11 GHz from 22.7 to 33.8 GHz and presents linearity of 18 dBm for the TX and a noise figure (NF) of 4.5 dB for the RX part with 20.7 dB gain.