A Broadband Reflectarray Using Phoenix Unit Cell

In this letter, a novel broadband single-layer reflectarray element composed of a circular patch and double circular ring is presented. The element in the reflectarray provides a nearly 360 ◦ linear phase range and has rebirth capability. The broadband characteristic of this reflectarray is obtained due to the sub-wavelength of the element space and the combination of two resonators of complementary size on a single layer. Then, a prime-focus 225-element microstrip reflectarray with this Phoenix cell has been designed and implemented. The measured gain is 22 dBi with 1 dB drop within 29% bandwidth at the center frequency of 10 GHz.