An electrically small impedance-matched microstrip antenna design

In traditional antenna design, a rule of thumb is that an impedance-matched antenna has to be wavelength compatible in size. It is not possible to design an electrically small antenna with matched impedance. In our previous studies, it was found that the operating frequency of a patch antenna could be reduced to 1/3 or even 1/4 of the original operating frequency using a loaded capacitor. By making use of dual capacitor loading, the operating frequency of the patch antenna could be reduced further. With proper choice of the loaded capacitors and the feed location, an electrically small microstrip antenna with matched impedance is found. This electrically small microstrip antenna design is presented. Like the previous capacitor loaded patch antenna, the operating frequency of this electrically small microstrip antenna could be tuned according to customer requirement. Simulated as well as measured result of the electrically small antenna are shown.