This article presents a $C$ -band multibeam phased-array receiver for high-throughput wireless communications. The proposed four-element beamformer supports 1–8 co-aperture simultaneously reconfigurable beams and demonstrates a 23-dB gain and a 6.5-dB noise figure (NF) at 5 GHz. In addition, it leverages a large-signal nonlinearity cancellation scheme and achieves a −10.8-dBm input 1-dB gain compression point (IP1dB) and a −4.7-dBm input third-order intermodulation intercept point (IIP3) at 5.5 GHz. By using the proposed merged gain-programmable phase shifter (GPS) technique, the beamformer achieves 32-path amplitude and phase control with high accuracy and a compact chip area. The entire chip occupies $6.4\times3.1$ mm2 area and consumes 1265 mW. To tackle the design challenge of the onboard multibeam-forming network, the proposed receive phased array adopts a scalable slat-type array configuration, enabling a low-cost design with high isolation. To the authors’ knowledge, this work demonstrates the largest number of concurrent co-aperture beams among integrated radio frequency (RF)-beamforming phased arrays.