High-Gain 100 GHz Antenna Array Based on Mixed PCB and Machining Technique

Abstract

A W-band 8 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> 8 slot-enhanced antenna array with high gain and high aperture efficiency is proposed based on the mixed printed circuit board (PCB) and machining technique. The antenna array consists of 16 2 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> 2 antenna subarrays. The substrate-integrated waveguide (SIW) cavity is used to feed the antenna subarray, where electromagnetic fields distribute in the TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">220</sub> mode. The SIW cavity is fabricated by the PCB technology for low cost, low profile, and lightweight. To reduce the loss of the feeding network, a constant-amplitude in- phase power divider based on ridge gap waveguide (RGW) is adopted to feed the SIW subarray using the machining technique. Besides, the standard WR-10 waveguide to the RGW transition structure is designed for measurement. The entire antenna array is integrated and packaged in a metal box. The measured results show that the impedance bandwidth of the antenna array is 97.8–107 GHz with a reflection coefficient lower than −10 dB. Within the impedance bandwidth, the antenna array gain is higher than 24.0 dBi, and the peak gain is 26.5 dBi. Moreover, an aperture efficiency of the antenna is larger than 75%.