Novel Broadband Reflectarray Antenna with Windmill-Shaped Elements for Millimeter-Wave Application

Abstract

A novel broadband millimeter-wave reflectarray antenna composed of windmillshaped elements of variable lengths is proposed. Compared to the conventional single-layer reflectarray elements, the windmill-shaped elements can realize much larger phase variation range (over 600°), leading to broader bandwidth. Using this technique, a 15°-beam-steering reflectarray operating at 30 GHz is designed. The computed results demonstrate the agreement of the main beam steering with the design requirement, and a 1-dB gain bandwidth close to 20% is obtained. The validity of the obtained results is verified by comparing the ones generated by Ansoft High Frequency Structure Simulator (HFSS) with those produced by Ansoft Designer. The antenna is useful for millimeter-wave applications.

Bandwidth Considerations for a Microstrip Reflectarray

“…The more recent approaches involve the use of different resonant size elements such as square rings, or more advanced shapes such as windmill or compound-cross-loop [6][7][8][9][10] to achieve the same aim of having the phase range greater than 2π. However, none of these works address the question how the phase characteristics of the reflectarray elements should behave as function of frequency to achieve its wideband operation.…”

Broadband and Broad-Angle Low-Scattering Metasurface Based on Hybrid Optimization Algorithm

“…It is composed by an inner square ring and an outer irregular ring, and their resonance frequencies are designed to be very close in order to increase the operation bandwidth and the reflection phasing range. The curves of the reflection phase from 6 GHz to 14 GHz is almost linear, and they are nearly parallel with the change of L (the length of the branch of the outer ring), showing excellent broadband frequency response as required32. Here we choose the dimensions of the basic element in Fig.…”

A Reflectarray Antenna Backed on FSS for Low RCS and High Radiation Performances

“…1 [18]. Because the phase characteristic acquired for the normal wave incidence provides a good approximation for the cases of TE and TM wave incidence for an angle up to 30 • from the reflectarray boresight direction [19], normal wave incidence is considered to obtain phase characteristic.…”