Meandered Slot and Slit Loaded Compact Microstrip Antenna with Integrated Impedance Tuning Network

In this paper, novel compact broadband dual frequency microstrip antennas are presented and broad-band impedance matching is proposed as a method for improve the matching level of antennas. The first 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 surface. The second proposed design consists of a rectangular microstrip antenna with a meandering slits. With the first proposed design a size reduction of 34% and 45% for the two resonant frequencies is obtained respectively. The two frequencies have an operation frequency ratio of 1.30 and 1.25. The theoretical design implementation of compensated compact rectangular microstrip antennas with new configuration Pi-matching networks was presented. A new compensation network consisting of RC Mutator circuit and discrete capacitors are employed at the input of the microstrip antenna operating at 1.5 GHz and 2.5 GHz. The performance parameters of the designed microstrip antenna with and without compensation network were compared. The results show that compensation network can improve the return loss level and the resonant frequency can be controlled in a wide RF band.