A New Dual-band Microstrip Antenna with U-shaped Slot

Microstrip antennas are widely used in many applications due to their low profile, low cost and ease of fabrication. In some applications it is desired to have a dual band or multiband characteristics. These characteristics can be obtained by coupling multiple radiating elements or by using tuning devices such as varactor diodes [1, 2]. However, these methods make antenna more complicated. A simple method to achieve the dual band characteristic in a microstrip antenna is embedding a slot in the patch as the structure proposed in [3] in which the radiating patch includes a pair of step-slots. In microstrip antennas, embedded slots can also be used to enhance the impedance bandwidth of a single band antenna. A circular arc slot [4] and a U-shaped slot [5] have