Monolithically Integrated Corporate-Fed Cavity-Backed Antennas

A Ka-band monolithically integrated 4$\,\times\,$ 1 corporate-fed cavity-backed patch antenna array is demonstrated in this paper. A single antenna element has four slits introduced to extend the bandwidth to about 8%. Its gain and radiation efficiency are 6.3 dBi and 97%, respectively. A rectangular $\mu$ -coaxial line based combining network is monolithically integrated with radiating elements in a slightly modified tile configuration. Specifically, to reduce the array footprint power dividers are aligned along the array axis. Combining network has height 1/2 that of the array and feed lines do not route through the antenna elements. Overall loss of the combining network is 0.5 dB at 30 GHz. Measured reflection coefficient bandwidth and maximum gain of the fabricated 4$\,\times\,$ 1 corporate-fed array are 13.7% and 12.73 dBi, respectively. The array is designed and fabricated in a recently developed surface micromachining process known as PolyStrata.