Frequency Reconfigurable Microstrip Circular Patch Antenna for Wireless Devices

In this paper, a frequency reconfigurable circular antenna design and development is proposed for wireless devices. In the proposed design, a circular patch antenna with circular slot using two PIN diodes at the centre frequency 10 GHz was designed and simulated frequency reconfiguration is achieved in the frequency range of 9.69-10.2 GHz and the measured results shows the same effect in the frequency range of 10.33-11.01 GHz. The frequency reconfiguration is carried out by switching the diodes on/off states. In the fabricated structure of proposed geometry the diodes are replaced by microstrip line for on-state as an ideal case. The antenna is designed on FR4 substrate (εr= 4.54) of thickness (H) 1.6 mm. The proposed structure was simulated by using the electromagnetic (EM) simulation software. The optimized structure was fabricated using microwave integrated circuit (MIC) techniques on same substrate. The return loss was measured using the Vector Network Analyzer. The simulated and measured return loss shows the close agreement.