Transformerless CMOS Series Doherty Power Amplifier Design for 5G V2X Wireless Communications

This paper presents and compares two transformerless Series Doherty Power Amplifier (SDPA) architectures that are designed with a Wilkinson and Active balun power driver for 5G Vehicle-to-everything (V2X) communication.The proposed SDPAs utilize LC balun to set gate-source voltage of main Power Amplifier (PA). The innovative use of a balun as a replacement for the transformer in both proposed SDPA architectures has demonstrated improved reliability while also designs with reduced area and cost of the system. Additionally, lumped elements are used instead of the bulky λ/4 transmission line which used for the load modulation. Compared to the conventional parallel Doherty power amplifiers, the proposed SDPAs achieve reduced area designs. The SDPAs were designed and simulated using the 65 nm CMOS process at a frequency of 5.9 GHz. The power gain of the SDPA, which uses the Wilkinson power divider, is 12.65 dB. The SDPA also exhibits a power-added efficiency (PAE) of 23.8% and a drain efficiency (DE) of 29.45%. The compression point (P-1dB) of the SDPA is 10.3 dBm. The SDPA using the Active balun delivers a power gain of 21.66 dB, a PAE of 16.77%, a remarkable DE of 41% indicating a high degree of efficiency. The compression point (P-1dB) of this SDPA is 15.6 dBm.