2 GHz electromagnetic crystal reflector antenna

The radiation pattern of a monopole antenna with a small electromagnetic crystal (EMXT) reflector was investigated. High frequency structure simulations predict a considerable amount of near-field shielding with undisturbed antenna impedance matching when a perfect magnetic conductor reflector is positioned near the monopole. The pattern distortion created by the reflector gradually decreases, reaching a minimum in the far field. Experimental results show the monopole with an EMXT reflector, /spl lambda//sub 0//4/spl times//spl lambda//sub 0//2 in size, produces a radiation pattern with a front-to-back ratio of 10.8 and 5.7 dB in the near and far fields, respectively.