Impact of Dielectric Substrate, Feed Connector, and Fabrication Tolerances on the Performance of Planar Millimeter-Wave Antenna Arrays

In this paper, the impact of dielectric substrate, feed connectors, and fabrication tolerances on the performance of planar microstrip mmWave antenna arrays is elucidated. Three similar prototypes of an 8-element wideband series-fed microstrip array, covering the entire 57-71 GHz ISM band, are designed by using three dielectric substrates (RO3003, RO5880, and RO4003C). The influence of the dielectric substrate on -10 dB impedance bandwidth, radiation efficiency, total efficiency, realized gain, sidelobe level, and radiation patterns is thoroughly analyzed through extensive numerical simulations. Moreover, a realistic 3D model of a microstrip edge-fed solderless 1.85mm V-connector is co-simulated with the array design, and its impact on mmWave antenna radiation characteristics is investigated. Furthermore, antenna fabrication tolerances and practical measurement effects at high frequencies are highlighted. These findings offer valuable insights when choosing dielectric substrates and taking into account connector effects while designing mmWave array antennas for a diverse range of futuristic mmWave applications.