A Monolithically Polyjet 3-D Printed Millimeter-Wave Quasi-Planar Air-Filled Cavity-Backed Patch Antenna With Enhanced Gain

In this paper, a new class of monolithically integrated millimeter-wave quasi-planar cavity-backed patch antenna is proposed. The antenna is shaped in the cross-sectional profile of the backed cavity and an air-filled trapezoidal backed cavity is developed with flexible design in the height and inclination. The shaped air-filled trapezoidal backed cavity allows the antenna gain to be improved significantly and it is tailored for being additively manufactured. A $Ka$-band antenna prototype is devised, manufactured, and tested. The antenna prototype is manufactured monolithically by employing high-precision Polyjet 3-D printing process. The RF-measured result of the antenna shows reasonable directional radiation performance with a reflection coefficient of less than -10 dB from 26.9 to 31.7 GHz (a relative bandwidth of about 16.4%) and an in-band peak realized gain of 7.8 dBi.