Design and development of high-gain wideband circularly polarized patch antenna

New design of obtaining circular polarization (CP) radiation of a single-feed microstrip antenna is presented. The antenna substrate has an air-layer with thickness about 2.5% of the wavelength at a resonant operating frequency. By using a short probe pin the antenna can be excited easily. The two truncated opposite corners technique is used to obtain the circular polarized operation by selecting an optimal size of truncating. A flat ground plane with an optimal position for the probe pin is used to generate an impedance matching with a wide bandwidth. The CP patch antenna built for IEEE 802.11b/g (2.4 GHz ~ 2.4835 GHz) frequency bands. Measured -10 dB bandwidth is 14.3% and the measured S11, maximum gains and half-power beamwidth are, -41 dB, 8.3 dBi, 75deg respectively. The details of design and experimental results for the proposed design are presented and discussed.