A Wideband Bidirectional Amplifier Using Neutralized Technique for 5G Communication

In this paper, we propose a wideband bidirectional amplifier (BDA) to support 28/38 GHz. The bidirectional mechanism is implemented by the two cross-couple neutralized common source (CS) amplifiers and also uses the magnetically coupled resonator (MCR) structure to achieve the wideband design. To improve output power, the output stage uses the series combine technique by two transformers. The measured $\mathrm{P}_{\mathrm{s}\mathrm{a}\mathrm{t}}$ are 11.21/10.7 dBm at 28/38 GHz in Tx mode, and the measured noise figure are 7.05/6.4 dB at 28/38 GHz in Rx mode. The measured 3-dB bandwidths (BWs) are 14/22 GHz at Tx/Rx mode, respectively. The dc power are 179/52 mW with 1.0 V supplied voltage in Tx/Rx mode. Compared with other BDAs, this BDA has the widest 3-dB BW.