On a Broadband Elevated Suspended-Plate Antenna with Consistent Gain

A design concept for elevating suspended-plate radiators is presented in this paper. The proposed antenna comprises two radiators connected by a folded feeding structure. The folded structure suppresses the occurrence of higher-order modes when the height of the antenna is elevated beyond 10% of the free-space wavelength, lambda₀ . The broadband radiating mechanism is explained. Both the simulation and measurement results show that a consistent gain of 7.2 dBi to 8.5 dBi is achieved over a frequency range of 2.3 GHz to 3.6 GHz, namely within a 44% impedance bandwidth for |S₁₁|< -10 dB. The concept is used to design two cost-effective broadband antennas covering both WLAN and WiMAX operations.