Design and characterization of polarizing grid as sub-reflector in folded reflectarray antennas

Polarizing grids are used as sub-reflectors in folded reflectarray antennas, which transmit orthogonal polarization and reflect, parallel polarization. Complete design and characterization of polarizing grid for use with reflectarray antenna is presented. The concept of polarizing grid is tested with a prototype polarizing grid, which is characterized using a waveguide simulator at X-band and later polarizing grid of dimensions 171mm × 171mm is designed and characterized using transmission and reflection method using two horn antennas as transmitting and receiving antennas. The measured polarizing grid shows a transmission loss of below −25dB when E-field vector of transmitting horn is parallel to metal lines in polarizing grid and a transmission loss of almost 0dB, when E-field vector of transmitting horn is orthogonal to metal lines in polarizing grid.