A dual-frequency, frequency tunable patch antenna based on printed superstrate layer

A patch antenna with printed superstrate layer for dual-frequency operation is presented. A metallic parasitic split-loop in meander shape is printed on the superstrate in order to produce a second resonance in terms of electromagnetic coupling resonance effect. In the design, the tunable frequency response is achieved by changing the length of the strips incorporated in the loop. Simulation results show that the double operation bands are centered at resonance frequencies 2.34 GHz and 2.45 GHz with the −10 dB bandwidths 1.2% and 0.8%. At the two resonance frequency centers, the gains 7.48 dBi and 6.25 dBi, and the radiation efficiencies 85% and 72%, are obtained, respectively. A tunable frequency range from 2.28 to 2.35 GHz for the lower frequency band is verified.