Analysis of reflectarray unit cell with capacitive effect

This paper presents an analysis of reflectarray antenna in simple patch design unit cell with the effect of varactor diode integrated. The small shift of resonant frequency with capacitance varying results in changes of reflected phase of operating frequency. The reflected phase adjustable of element is required for reconfigurable reflectarray design. It will further contribute the phase shift capability that is required in beam scanning for microwave applications, terrestrial and satellite communications at Ku-Band. The design concept of active reflectarray unit cell is proposed. Simulated results are executed by commercial full-wave electromagnetic software CST MWS covering the unit cell performance shows promising result. It demonstrates the progressive phase range up to 300° with maximum 3.13 dB loss for four operating frequencies in range of 13.666 to 14.006 GHz with capacitance varying of 0.05pF to 1.8pF. The main beam scanning of the design approached may start with 10° to 30° which is near to broadside.