Reconfigurable Reflectarrays Based on Optimized Spiraphase-Type Elements

Abstract

Reconfigurable spiraphase-type reflectarrays based on ring slot resonators with switchable radial stubs are presented. The mathematical model of the infinite array was used to optimize the spiraphase-type element at 36.5 GHz. The optimization goals were to minimize the dissipative loss in the p-i-n diode switches and to reduce the cross-polarization radiation. The mathematical model of the finite array was then used to simulate the radiation characteristics of a reconfigurable reflectarray with 277 optimized elements for different scanning elevation angles . The calculated aperture efficiencies were 0.42, 0.40, 0.36, 0.25, 0.16, and 0.12 for equal to 0 , 20 , 30 , 40 , 45 , and 50 , respectively. For validation of the numerical simulations, three 277-element reflectarrays for fixed of 0 , 20 , and 30 were designed. Metal strips and open circuits were used instead of the forward and reverse p-i-n diode states, respectively. These reflectarrays were then fabricated and tested, demonstrating aperture efficiencies equal to 0.41, 0.40, and 0.28 for equal to 0 , 20 , and 30 , respectively. Measured characteristics agreed satisfactorily with theoretical predictions.

Bandwidth Performances of Reconfigurable Reflectarrays: State of Art and Future Challenges

“…Active reflectarrays based on the use of PIN-diode switches are proposed in [20][21][22]: a microstrip reflecting element with a single-bit phase shifter is adopted in [20] to design a large electronically reconfigurable reflectarray antenna for millimeter-wave imaging systems, operating in the 60-GHz band; a 36.5 GHz spiraphase-type reflectarray, based on reactively loaded ring slot resonators with switchable radial stubs, is discussed in [21], [22].…”

Beam-Scanning Reflectarray Antennas: A technical overview and state of the art

“…A 244-element beam-switching X-band reflectarray antenna using p-i-n diodes was also demonstrated in [72]. Another very interesting application of p-i-n diodes is in electronic element rotation that was initially proposed in [73], where selective activation of the lumped elements of the rotationally symmetric geometry mimics a rotation of the reflected electromagnetic wave [74]- [76].…”

A Dual Circularly-Polarized Multilayer Reflective Surface Based on Loaded Ring Slots

“…On the other hand, reflectarray antennas possess most of the main advantages of conventional phased arrays with the benefits of reduced losses, low complexity, and relatively low cost [1]. Recently, reconfigurable reflectarrays have become attractive due to their ability to perform dynamical reconfiguration of the radiation pattern, multibeam scanning, and multi-band operation [2][3][4][5][6][7][8][9].…”