Study on a way to broaden the beamwidth of microstrip antenna by vertical current

Abstract

In this letter, a method to broaden the beam-width of a microstrip antenna is investigated. Two metal walls are put at the bilateral sides of a microstrip antenna in the E-plane. Vertical current on the metal walls is induced by E-field from horizontal current on the radiating patch of the microstrip antenna. The beam-width of the antenna is broadened by the both the horizontal current and vertical current. A novel wide beam-width microstrip antenna is designed according to the proposed method. Some parameters which effect on the performances of the antenna are studied. The simulated and measured results of the return losses (≤ −10 dB) and radiation patterns are presented. The half-power beam-width (HPBW) of the proposed antenna is obviously improved comparing with the general microstrip antenna, which is 221° in the E-plane and 168° in the H-plane at 4.0 GHz.