A Novel Switchable Single- and Multifrequency Triple-Slot Antenna for 2.4-GHz Bluetooth, 3.5-GHz WiMax, and 5.8-GHz WLAN

A novel reconfigurable slot antenna with three switchable frequencies is presented. The uniqueness of this design is that it allows various groups of its frequency resonances to be selected electronically using three switches. Therefore, seven different states are achieved, and so three, two, or one resonances are possible at the same time. By using three sickle-shaped slots in the ground plane and three pairs of p-i-n diodes that are soldered between three metal strips inside the slots and the ground plane, the antenna can support 2.4-GHz Bluetooth and/or 3.5-GHz WiMAX and/or 5.8-GHz WLAN systems. The advantage of this design is that it overcomes the problem of conventional reconfigurable antennas of serving one frequency band at a time. The antenna design, simulation, and measurement results are presented. The antenna shows similar radiation patterns with low cross-polarization levels at all its operating frequencies. The simulated and measured results are in good agreement.