Design of a CPSS-based reflectarray cell with controllable reflected phase for dual-circularly-polarised reflectarrays

A first step towards the design of dual-circularly polarised reflectarrays with independent control of both polarisations is proposed in X-band. A reconfigurable unit-cell based on a circularly- polarised selective surface is studied at 8.5 GHz. It provides a 2-bit phase resolution in reflection for the left hand circular polarisation (LHCP) and is nearly transparent in right hand circular polarisation (RHCP). The simulated characteristics are excellent over a 6.4% bandwidth. The proposed unit-cell is fabricated using stacked substrates. A loss budget demonstrates that loss is quite balanced between loss in materials and polarisation conversion. Then, a study of the effect of realistic switches is shown in order to demonstrate that conventional p.i.n. diodes would cause an acceptable loss increase.

[1]  R. Gillard,et al.  A CPSS-based reflectarray cell with reconfigurable capabilities , 2012, 2012 6th European Conference on Antennas and Propagation (EUCAP).

[2]  R. Gillard,et al.  An FDTD optimization of a circularly polarized reflectarray unit cell , 2002, IEEE Antennas and Propagation Society International Symposium (IEEE Cat. No.02CH37313).

[3]  J. Encinar,et al.  Reflectarray antennas , 2007, Developments in Antenna Analysis and Design: Volume 2.

[4]  Alexander E. Martynyuk,et al.  Reflectarray based on three-bit spatial phase shifters: Mathematical model and technology of fabrication , 2009, 2009 3rd European Conference on Antennas and Propagation.

[5]  L. Shafai,et al.  Reciprocal circular-polarization-selective surface , 1996 .

[6]  J. Wang,et al.  Characteristics of a new class of diode-switched integrated antenna phase shifter , 1983 .