Reflectarray with Split Ring Resonators at 83.5 GHz

A single layer reflectarray utilizing split ring resonator (SRR) as unit cell element is proposed and designed in this paper. Different unit cells are analyzed with electromagnetic simulation software and SRR is chosen due to its relatively wide-band characteristics. Furthermore, it is shown that the reflection phase dynamic range exceeding 360. is easily obtained by using a time delay line with variable length. Due to high center frequency of 83.5 GHz, the challenges of the design lay in the small feature size, which reaches the limits of the standard PCB technology. Finally a 200mm x 200mm reflectarray is designed and measured. The measurement results of a fabricated prototype show 32.4 dBi gain and the half-power-beam-width (HPBW) of 1.5 degrees. To the authors knowledge it is one of the first PCB fabricated reflectarray designs at 83.5 GHz.