IMPLEMENTATION OF CROSS-SHAPED SLOT IN COMPACT MICROSTRIP ANTENNA

Abstract

A compact cross-shaped slotted microstrip patch antenna is proposed for circularly polarized (CP) radiation. A symmetric, cross-shaped slot is embedded along one of the diagonal axes of the circular patch for CP radiation and antenna size reduction. The structure is asymmetric (unbalanced) along the diagonal axes. The overall size of the antenna with CP radiation can be reduced by cross shaped slot. The symmetric cross-shaped slot cut within the first quadrant of the circular patch. There are huge demands for the miniaturization of the mobile communications equipment. Microstrip circularly polarized antennas are attractive in satellite communication systems owing to their good features such as low profile, light weight and easy to fabricate. A number of single-fed circularly polarized microstrip antennas are described. The major advantage of single-feed circularly polarized microstrip is their simple structure. There are a number of approaches to reduce the size of patch antennas . embedding cross slots of unequal length or equal lengths . In this thesis the performance of the cross-shaped microstrip antenna is studied with various types of substrate which have different types of electrical permittivity with same thickness is about 1.6mm. Now a days the Selection of the most suitable substrate for a Microstrip antenna is a prime important. There is because of many limitations of the microstrip antenna such as high return loss, low gain and low efficiency can be overcome by selecting an appropriate substrate for fabrication of the antenna. The substate properties such as its dielectric constant, loss tangent have a pronounced effect on the antenna characteristics. The radius of circular patch is 24.8mm. The antenna is operated at 2.091 GHz, and built by using a Benzo-cyclo-buten material which gives good antenna parameters. The Electrical permittivity of this substrate is 2.6. with a coaxial probe single feed. All analytical results have been simulated by IE3D software.