A frequency re-configurable triangular shaped slot antenna for cognitive radio

An Antenna having a triangular shaped slot is proposed that has the ability to switch the frequency to thirteen different bands, one at a time, between the frequency 2.11GHz to 3.9GHz. To achieve frequency re-configurability, the length of inclined arms of the triangular slot is varied by use of six PIN diodes which are placed along the perimeter of the triangular slot. Frequency tuning ratio of about 1.85:1 can be achieved using this design. Results such as return losses, gain, bandwidth and radiation patterns are presented in this paper.