Abstract: The Radio Frequency Identification (RFID) was introduced as a new technology of Barcodes. RFID is automatic identification technology which uses radio frequency electromagnetic field to identify object carrying tags when they come close to the reader. Antenna are utilized respectively at the reader and the tag namely, reader antenna and the tag antenna. The purpose of the reader antenna is to process a transmitting / receiving so the reader can identify the presence of one or several RFID tags. RFID tags features and electronic chip with an antenna in order to pass onto the interrogator. Since the tag antenna on normally linearly polarized, circularly polarized radiation of reader antenna is preferred in order to make the identification reliable and more efficient, regardless of the physical orientation of the tag antenna. One of the important things in RFID tag is reduce size with conserving a good read range. This is can be achieved through developing a small antenna with high gain. Antenna design has played a critical role in the increasing development of RFID technology. Microstrip antenna is the best form of the printed antenna was designed by ADS simulation tool a modification to prevailing design is tried out and comparable results are obtained. This paper present the Design of the patch antenna with the hybrid coupler where the Return loss, Gain, Directivity is discussed for same patch antenna with an increase in its slots. The size of the element is determined by the operating frequency, dielectric constant and height of the substrate. Later the antenna was measured by using VNA (Vector Network Analyzer) to perform the antenna measurements.

Keywords: ADS, Microstrip antenna, Hybrid Coupler, RFID.