A broadband CPW-fed loop slot antenna with harmonic control

Photonic bandgap (PBG) structures with cross-shaped or square-shaped lattices have been incorporated into the antenna feed network for harmonic suppression. Experimental results show that PBG structures not only exhibit well-behaved bandstop characteristics, but also enhance the bandwidth of the proposed antennas. For the proposed antenna with square-shaped lattices, the 10 dB return loss bandwidth could reach 1541 MHz (1525-3066 MHz), which is about 70% with respect to the center frequency of 2200 MHz; for the antenna with cross-shaped lattices, the bandwidth could reach 1320 MHz (1560-2880 MHz), which is about 60% with respect to the center frequency of 2200 MHz.