Compact Dual-Strip Coupled Dual-Patch Antenna for Millimeter-Wave AiP Applications

A millimeter-wave (mm-wave) dual-strip coupled dual-patch antenna is proposed, which is achieved by high density interconnect antenna-in-package process. The dual patches and dual strips are closely placed on the same layer and produce two resonances with broadside radiation and x-direction polarization. Compared with the state-of-the-art single-layer patch antennas, the proposed antenna can achieve both compact radiator size and wide bandwidth, which is useful to form mm-wave array. Furthermore, the antenna radiator and the feedline are separated by the antenna ground to decrease the interaction from radio frequency components in the active system. Characteristic mode analysis method is utilized to analyze the antenna element to reveal the modal behavior of the proposed antenna. For demonstration, a prototype of 2 × 4 array is fabricated, which has the antenna element size of 0.36 × 0.37 × 0.05 λ
₀
³
(λ
₀
is the operating wavelength at 26 GHz in free space), the 10 dB impedance matching bandwidth of 20.6% (22.7-27.9 GHz), and the peak gain of 14.2 dBi.