Circular Microstrip Antenna Backed by Rectangular Slots Cut Ground Plane for Enhanced Antenna Characteristics

A novel design of circular microstrip antenna by employing rectangular slots cut modified ground plane profile is proposed, on thinner FR4 substrate. With the modifications in the resonant mode current paths and the fringing fields in the antenna cavity, as compared with a conventional ground plane design, proposed configuration yields 5.6% reduction in the resonance frequency, three times increase in the bandwidth, gain improvement by 0.5 dBi, and more than 40 dB reduction in the cross-polar level. As against the reported configurations in the literature, results obtained in the proposed design are better considering a single patch design, while employing a thinner and lossy substrate. The equivalent configurations of the proposed design can find applications in GSM 900 or Bluetooth and WLAN applications.