Frequency-Reconfigurable Bow-Tie Antenna With a Wide Tuning Range

A frequency-reconfigurable bow-tie antenna with a continuous wide tuning range is proposed. The antenna can be electronically tuned over the lower ultrawideband (UWB) frequency band (3-6 GHz) using a pair of p-i-n diodes and a pair of varactor diodes. By switching the p-i-n diodes, the antenna can operate at two distinct states. Further adjustment of the varactor diodes enables continuous tuning within these two states. When properly designed, these two tuning bands can overlap each other and realize a wide tuning range. Measured results show that the proposed antenna achieves continuous tuning from 3.04 to 5.89 GHz (51%) with stable radiation patterns and flat gains.