mmWave Flat Panel Phased Array Antenna Module With Enhanced Scanning Coverage

A compact mmWave phased array antenna module (PAAM) with wide beamwidth radiators to ensure seamless mmWave communication is proposed in this article. Unlike the typical PAAM consisting of patch-type elements with limited half power beamwidth (HPBW) around 90°, the proposed PAAM is configured by balanced multipole elements with extended HPBW in both E- and H-planes. Due to the extended HPBW of the proposed antenna element, the proposed PAMM can steer main beams for wider angles with lower side lobe levels. First, a single mmWave wide HPBW antenna element was fabricated and verified at 28 GHz, showing the measured HPBW of 148.3° and 141.3° in E- and H- planes, respectively. The measured HPBW of the proposed antenna showed more than 96% inrease in both planes, comparing with the conventional patch at 28 GHz. Moreover, $1\times 4$ PAAM was fabricated by integrating the antenna array directly with a 4-channel beamforming IC to further verify the mmWave communications at 28 GHz with minimized blind spots. With 64-QAM over-the-air (OTA) test, the proposed PAAM showed the measured error vector magnitude (EVM) less than 7.1% at ±75° ranges while the conventional patch-based PAAM showed the measured EVM of 27.8% at ±75°.