Socket Design for 1x4 mmWave Antenna in Package with Beamforming Testing

In this study, we present a 1x4 broadband dual-polarized antenna array built on a 10 (4+2+4) multilayer organic substrate and assessed with a test socket. The design comprises stacked patch antennas featuring parasitic elements to improve operating bandwidth, and the optimal substrate configuration was selected to ensure cost-effectiveness. Through the implementation of an effective grounding strategy for the parasitic elements, a short-circuit mirror-image current effect is achieved, which in turn results in a notable reduction in component area. Following optimization, the dimensions were reduced from 6.5 x 25 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>to 4.5 x 25 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>, representing a 31% decrease. The test socket, comprising a load board and socket for the assessment of the antenna array's characteristics, enables the measurement of the antenna array's realised gain in both vertical and horizontal polarisation within the 26.5 to 29.5 GHz range, with values ranging from 7 to 9 dBi.