Frequency Reconfigurable Bow-Tie Antenna with Artificial Magnetic Conductor Loading

This letter presents a unidirectional frequency reconfigurable bow-tie antenna (FRBA) with three switchable operating bands covering Bluetooth, WiMAX, and WLAN bands. The reconfigurability is realized by changing the effective electrical length of the radiator, which is accomplished by attaching six PIN diodes on the bow-tie arms. To produce a unidirectional radiation pattern with low back radiation level and increased gain, while still maintaining low-profile structure, a tri-band artificial magnetic conductor (AMC) is designed and placed underneath the antenna as a back reflector. The distance between the upper surface of the AMC reflector to the bow-tie radiator is only 0.032 lambda(0) at the lowest operating frequency of 2.4 GHz. Experimental results show that the frequency switchable function can be easily achieved with end fire radiation patterns.