A novel 2-bit reconfigurable reflectarray element for both linear and circular polarizations

A novel 2-bit reconfigurable reflectarray element for both linear and circular polarizations is proposed. The element structure is a microstrip patch backed by a slot-loaded plane. Combining the current reversal mechanism and tunable resonance approach, five PIN diodes are integrated on the slots to control the current direction and effective slot length, which lead to a tunable phase shift. The simulated results show that this element has a desired 2-bit phase resolution at L band and low element loss of less than 0.31 dB. The 1-dB element loss is obtained within a wide bandwidth of 24.7%.