Design and study of a broadband patch antenna with a vertical plate pair as a differential feeding scheme

Abstract

Conventional patch antennas in general have a conducting patch on a grounded patch, and have the attractive features of low profile, easy fabrication, and conformability to mounting hosts. Patch antennas however have a narrow bandwidth, and bandwidth enhancement is usually demanded for practical applications. In addition to being broadband, they should be capable of operating in multiple frequency bands too. The finial year report presents a wideband patch antenna with vertical plate pairs for improving impedance bandwidth and higher gain. In addition, the information acquired from these techniques is appropriately used to explain the design and operation of the patch antenna. The differential-fed patch antenna with a floated plate pair combines the use of a slot, parasitic patches and capacitive loads to achieve wideband operation. A broadband differential-fed patch antenna with good radiation pattern is proposed. Unlike conventional differential-fed patch antennas, the proposed antenna employs a vertical plate pair as the differential feeding scheme. To demonstrate the devised feeding approach, impedance bandwidth of up to 75% (SWR<2) has been achieved. More importantly, symmetric radiation pattern, low-cross polarization level and stable radiation pattern are realized within the band. In addition, the impedance bandwidth of proposed antenna can be improved to 90% by parasitic patches which are stacked on the top of driven patch or are directly coupled on the radiating edges.