A Low-Loss T/R Module With Balanced Power Amplifier for High Antenna Impedance Tolerance

The balanced power amplifier (BPA) topology is commonly used in applications requiring high antenna impedance tolerance. This paper presents a low-loss transmit-receive (T/R) front-end module (FEM) with BPA using four shunt switches. These switches are embedded into the output network of the BPA and the input matching network of the common source low noise amplifier (LNA). A prototype T/R FEM is implemented in bulk CMOS 65 nm technology for the 5G FR2 n260 band. As per simulations, the extra loss due to the T/R interface in transmit mode is 0.75 dB, and the noise figure (NF) degradation in receive mode is 1.5 dB. The prototype chip is characterized by die-probing. The BPA delivers a saturated power output of + 18 dBm with a power-added efficiency (PAE) of 14.5 % at 40 GHz in measurements. The LNA has a gain of 21.3 dB and a noise figure of 5.8 dB in the n260 band.