Reflectarray element using interdigital gap loading structure

A novel reflectarray element using an interdigital gap loading structure is proposed. A wide reflection phase range of more than 1000° is obtained, which can support a sufficient phase range for a large scattering angle (up to 60°) reflectarray. Furthermore, this element has a feature of equal element size because the reflection phase is adjusted by controlling the finger length of the interdigital gap. Thus, abrupt geometry variations for consecutive cells in the traditional reflectarray can be avoided. A Ku-band reflectarray has been fabricated and measured results show good agreement with simulation.