Slot-loaded Rectangular Microstrip Antenna with Meandering Slots in the Ground Plane for Compact Broadband Dual-frequency Operation

In this paper, a novel compact broadband dual frequency microstrip antenna is presented. The proposed design consists of a rectangular microstrip antenna with a pair of parallel slots loaded close to the radiating edge of the patch and three meandering narrow slots embedded in the antenna´s groundplane. Experimental study was carried out by varying the length of the meandering slot. Using three meandering slots in the groundplane a significant lowering of the both resonant frequencies is obtained with an enhanced operational bandwidth in comparison to standard rectangular microstrip antenna without slots. An increase in the bandwidth is more significant for lower resonant frequency. With the proposed design a size reduction of 50.6% and 30% for the two resonant frequencies is obtained with the measured bandwidths of 12.2% and 4.5% respectively. The two frequencies have an operation frequency ratio of 1.40.