BROAD PHASE RESPONSE UNIT CELL AND HIGH GAIN REFLECARRAY ANTENNA DESIGN WITH CIRCLE-MINKOWSKI STRUCTURES

In this study, it is aimed to increase the phase responses of the obtained unit cells by using the fractal structures nested together. Then, the effect of these obtained broad phase-response unit cells on the antenna gain is examined by using them as reflective elements on the reflect array antenna. For this purpose, 3 different structures are designed: the circle, the Minkowski used in the circle, and the unit cells obtained by rotating the Minkowski structure in the circle. The phase response of the first designed circle structure could not meet the phase requirement for a whole band, and a phase response of 280 degree is obtained. Then, in the second stage, the Minkowski structure is designed in the designed circle, and a phase response of 329 degree is obtained in this structure. Finally, a structure sufficient for the entire phase response is obtained by rotating the Minkowski structure in the circle between 0-30 degree. A unit cell with a wide phase response and a 11.7 dBi horn antenna and reflect array antenna are designed. The gain of the designed reflect array antenna has increased by 91% compared to the horn antenna and has been obtained as 22.4 dBi. With this result, it has been revealed that the phase response can be increased by using fractal structures together and especially by rotating the structures, and with this method, high-gain reflect array antennas with broadband phase response can be designed.