Size reduction and tuning of integrated folded patch antennas using slots

We report on the use of slots for sue reduction and tuning of folded patch antennas operating in the 5-6 GHz ISM band, with intended application in short-range wireless communications. Varying the slot length modifies the antenna electrical length, thus providing a new degree of freedom to control the antenna operating properties, and is the main novelty of our work. This technique was used for antenna tuning, input impedance control, and, very important, for antenna sue reduction. Keeping the operating frequency at 5.7 GHz, application of slots allows an antenna sue reduction close to 30%. Keeping the antenna dimensions constant, application of slots allows its tuning from 5.7 GHz down to 4.8 GHz and is potentially suitable for dynamic antenna reconfiguration.