A Wideband Antenna for mm-Wave Antenna-in-Package Application

Abstract

Antenna-in-Package has been widely applied for millimeter-wave systems that integrate the MMIC chip and antenna into one package. For organic substrate Antenna-in-Package solutions, probe feeding and aperture-coupled feeding patches are generally used as radiation units. In this work, a patch antenna is proposed using coupled resonation; a wideband, high-gain and compact 3-D antenna package integration is realized. Equivalent circuit model is analysed for the coupled structure. coupled line is adopted for impedance matching, the whole antenna is designed on the same thick radiation patch substrate, with less organic substrate lamination layers. For millimeter-wave Antenna-in-Package structures, vias are generally used for vertical interconnections, which function well in the lower millimeter-wave frequency range. For operation frequency higher than 100 GHz, design difficulties may be encountered for via interconnection, with performance degeneration on impedance matching and transmission loss. In our work a H-shaped slot is integrated instead of vias on an organic substrate, realizing a high frequency and wideband mm-wave transition. An interconnection structure is also adopted to convert a microstrip line to differential microstrip line in the feeding network. Antenna prototype with 2× 4 radiation array is designed for verification purpose at 20 GHz frequency range with simulated bandwidth of 23%. The prototype is fabricated with separate PCB boards assembled with screws; measured antenna gain is 12.7 dBi - 13.5 dBi. The proposed structure provides a wideband and low-loss solution for potential higher frequency mm-wave Antenna-in-Package applications.