Effects of dielectric superstrates on a two-layer electromagnetically coupled patch antenna

Experimental results on the radiation and impedance characteristics of a two-layer EMCP (electromagnetically coupled patch) antenna covered with dielectric superstrate are presented. It was found that, for a two-layer EMCP antenna operating in the high-gain region, the resonant input impedance increases and the 3 dB beamwidth decreases with the superstrate thickness. When the antenna is operating in the broadband region, both the resonant frequency and the bandwidth decrease with the superstrate thickness. In general, the impedance matching becomes poor with increases in superstrate thickness.<>