A Crooked U-Slot Dual-Band Antenna With Radial Stub Feeding

We propose a dual-band antenna using a crooked U-slot with radial stub feeding. This antenna has a simpler topology than other antennas designed for realizing dual-band characteristics. In addition, the proposed antenna adjusts to desired frequencies easily. The crooked U-slot made on the bottom layer provides the advantage of making impedance matching possible over a wide band at the low frequency, while the radial stub is used for feeding and also for providing additional resonance at the high frequency. The operating frequencies of the proposed antenna are chosen as 2.4 and 5.2 GHz, obtained by optimizing the physical dimensions of the crooked U-slot and radial stub. Measured results of return loss show -26.2 and -12.2 dB at 2.4 and 5.2 GHz, respectively. Measured gain is 0.47 and -1.97 dBi at 2.4 and 5.2 GHz, respectively.