Reconfigurable slot antenna using switched stub technique

A technique of designing a slot antenna with multi-band operation is described in this paper first. The design is based on introducing a short circuit point on the slot antenna for each additional required frequency band of operation. This will create different effective electrical slot lengths from a single-feed resonant slot. Examples of dual-band and tri-band slot antennas are provided. A feature of the proposed approach is that similar broadside radiation patterns are produced for each frequency band. Additionally the ratios between the frequency bands are flexible and easily designed. Then, by making the short circuit points in open or short states with switches, the proposed slot antenna is able to change the frequency response from single-band to multi-band operation.