Multilayer Dry Film Photoresist Fabrication of a Robust >100 GHz Gap Waveguide Slot Array Antenna

Abstract

This article presents the first use of a multilayer dry film photoresist to fabricate a slot array antenna by micromachining. The proposed fabrication process demonstrates a straightforward and fast method of realizing antenna structures and delicate features with very high accuracy above 100 GHz. The slot array antenna design is based on gap waveguide technology. The designed antenna consists of two layers: a slot layer and a feed layer with a transition to measuring waveguide. The antenna contains structures that require a multiple level dry film fabrication process with thicknesses ranging from 80 µm to 400 µm with ±10 µm tolerance. The fabricated antenna shows good accuracy. To make the fabricated antenna layers conductive, the fabricated polymer antenna was coated with Ti and Au. The input reflection coefficient was measured to be below -11 dB over a 10% bandwidth from 136-148 GHz, and the antenna gain was measured to be 11.4 dBi at 142 GHz, both of which are in fair agreement with simulations. A thermal cycling test has been conducted on the fabricated antenna and the results show insignificant degradation at least up to 300 cycles in the temperature range −50 • C to 135 • C which is the typical temperature gradient range for many practical outdoor wireless applications.INDEX TERMS Dry film photoresist, gap waveguide technology, microfabrication, micromachined millimeter wave antenna, slot array, thermal reliability.

A Novel SIGGW Dual Post Band-Pass Filter for 5G Millimeter-Wave Band Applications with a Transmission Zero

“…Also, the results are verified by simulation using CST. According to the results, the proposed filter is a good option for Ka-band applications and can be used as the building block for suppressing the LO leakage that is commonly used for up-converting the 5G signal to Ka band.Recently, manufacturing problems in mm-wave and THz designs motivated consideration of the gap waveguide technology [20][21][22] . Common types of gap waveguide technologies are groove gap waveguide (GGW) 23 , microstrip gap waveguide (MGW) 24 ridge gap waveguide (RGW) 25 and substrate integrated groove gap waveguide (SIGGW) 26,27 .…”

“…Recently, manufacturing problems in mm-wave and THz designs motivated consideration of the gap waveguide technology [20][21][22] . Common types of gap waveguide technologies are groove gap waveguide (GGW) 23 , microstrip gap waveguide (MGW) 24 ridge gap waveguide (RGW) 25 and substrate integrated groove gap waveguide (SIGGW) 26,27 .…”