Circular Microstrip Antenna with Off-Centered Y-Slot
A novel dual-frequency broadband design of a single-layer single-feed circular microstrip antenna with an off-centered Y-slot is demonstrated in this communication. By selecting a suitable location of the Y-slot in the circle, the proposed antenna on glass epoxy FR-4 substrate not only resonates efficiently at two closely spaced frequencies (2.736 and 2.868 GHz) but also offers improved bandwidth (210 MHz or 7.5%) in comparison with a conventional circular microstrip patch antenna (similar to 2%). From the measured results, almost identical broadside radiation patterns are obtained at two resonant frequencies, and the variation of less than 1 dBi in gain values is achieved in the frequency range where broadband behavior is observed. (C) 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE 21:407-412, 2011.
broadband microstrip patch antenna gain dual frequency