Frequency-Reconfigurable Archimedean Spiral Antenna

In this letter, a frequency-reconfigurable Archimedean spiral antenna is presented. The proposed antenna consists of a two-arm spiral fed by a coplanar waveguide (CPW) feeding line. A pair of meandered slotlines is implemented at both sides of the CPW-fed slot on the spiral antenna to introduce frequency reconfiguration. This antenna is able to configure operating frequencies from wideband mode (2-8-GHz band) to narrowband mode, which is at 5.8 GHz WLAN band, by switching the p-i-n diode integrated within the radiating antenna surface. Two p-i-n diode switches are located in the meandered slot to achieve frequency reconfigurability. Simulated and measured data are presented to verify the proposed antenna design.