A Wide-Angle E-Plane Scanning Linear Array Antenna With Wide Beam Elements

In order to improve the wide-angle scanning performance of the phased array antennas, a wide-beam microstrip antenna with metal walls is proposed in this letter. The beamwidth of the antenna is broadened by the horizontal current on the radiating patch and the vertical current on the metal walls. The half-power beamwidth of the E- and H-planes is 221° and 168° at 4.0 GHz. Furthermore, the wide-beam antenna element is employed in a nine-element E-plane linear array antenna. The main beam of the E-plane scanning linear array antenna can scan from -70° to +70° in the frequency band from 3.7 to 4.3 GHz with a gain fluctuation less than 2.7 dB and variation in maximum sidelobe level less than -5.8 dB. The E-plane scanning linear array antenna with nine elements is fabricated and tested. The measured results achieve a good agreement with the simulated results.