An 8-Channel 3–28 GHz High-Linearity Phased-Array Receive Beamformer With Gain Compensation for 6G FR3 Systems

This article presents a high-linearity eight-channel phased-array receiver operating at 3–28 GHz, designed for multiband base station applications using a 90-nm SiGe BiCMOS process. The chip employs RF beamforming and integrates eight channels with dual 4:1 combiner networks for dual-polarized, dual-beam operation. Each channel includes a switchable low-noise amplifier (LNA), an active phase shifter (PS) with a vector modulator (VM), and a variable gain amplifier (VGA), all optimized for high-linearity performance to mitigate interference. The input features a differential port to support ultrawideband antenna designs, while the output is converted to a single-ended port to simplify printed circuit board (PCB) routing. Measurements show an electronic gain of 25–34 dB, a noise figure (NF) of 2–4.5 dB, an input 1 dB compression point (${IP} _{1{dB}}$) of −35 to −28 dBm, and a power consumption of 150 mW across the operating bandwidth. The design targets 6G base station applications, with gain peaking at higher frequencies to compensate for PCB routing loss. For demonstration, a 16-element linear array with Vivaldi antennas is developed to showcase system-level performance. Over-the-air (OTA) testing shows ±50° beam scanning capability while maintaining high linearity with 64-QAM-modulated signals. These results highlight the potential of the proposed receiver for future multiband 6G FR3 systems.