Dual-resonance spiral-like shorted patch antenna

A simple dual-resonance printed antenna based on a spiral-like shorted patch configuration with an additional shorting pin to generate the second resonance is presented. The antenna allows for relatively independent control of the two resonant frequencies. The antenna resonance is at 1.55 and 2.5 GHz. The 10 dB return loss bandwidth is greater than 1.4% across each of the resonant frequencies.