Design of a W-Band Transformer-Based Switchless Bidirectional PALNA in 65-nm CMOS Process

In this paper, a W-band transformer-based bidirectional PA-LNA using 65-nm CMOS process is presented. In this work, the paper presents switchless PA-LNA uses current-type transformer as a bidirectional matching network for PA and LNA inputs/outputs without using lossy T/R switches. As a side benefit, avoiding the use of the T/R switches not only saves the chip area, but also prevents performance degradation in PA and LNA modes. Due to these design features, the proposed switchless PALNA achieves a peak small-signal gain of 17.2 dB in PA and 18.5 dB in LNA mode and 3-dB bandwidth covers from 74 to 95 GHz, while LNA mode achieves minimum noise figure of 7 dB at 81 GHz. In the PA mode, it achieves the measured peak saturated output power of 10 dBm with 9.1% peak power-added efficiency and 8 dBm peak 1-dB output power at 75 GHz. The chip size is 0.46 mm².