Wideband high-impedance surface reflector for low-profile high-gain UHF antenna

A novel low-profile high-gain UHF antenna for Digital Television (DTV) is presented using an appropriately designed wideband High-Impedance Surface (HIS) reflector. The proposed design is an improvement of the structure presented in previous work. The effect of an air gap between the HIS substrate and its back ground plane is investigated in an effort to produce a high-gain, low-profile and lightweight structure. Low-cost substrates are employed in the design, rigid PVC for the antenna and foamed PVC for the artificial ground plane. PVC substrate is ecologic, recyclable, long lasting and cheap. A microstrip-fed monopole mounted on the proposed HIS reflects effectively in-phase field over a bandwidth of about 56%. Hence, significant enhancement in antenna gain has been achieved, around 7 dBi peak gain with respect to the simple monopole. The overall structure is very compact (total height is 0.098λ). Details of the proposed antenna design and simulation results are described.