Electronically tunable reflectarray element based on C-patch coupled to delay line

A reflectarray element with switchable phase shift for an electronically beam scanning reflectarray operating in the X-band is presented. The element consists of multilayer printed circuits with a C-patch coupled to a delay line through a ring slot. The phase shift is obtained by adjusting the length of the delay line. The element integrated with a pin diode to control the phase is assembled and measured in the X-band. The experimental validations show a wide range of reflection phase with a quasi-linear phase curve as well as a promising capability of changing the reflected phase between the ON and OFF states of the PIN diode.