Suspended microstrip patch antenna with ground-shield tapered suspended stripline feed

In this paper, we present a single suspended microstrip patch antenna with a suspended stripline feed operating at 18 GHz. It consists of a single-layer, suspended antenna element, a low-loss suspended stripline feed and a novel ground-shield-impedance transformer. An efficient way to fabricate the proposed structure is demonstrated. An improved version of the antenna is fabricated and the -10dB bandwidth for the suspended antenna is 4%, the 3 dB beamwidth is approximately 55/spl deg/ and a highest value of measured gain is around 9.5 dB.