We present a polarisation rotator based on a dielectrically embedded metal Mesh Half Wave Plate (MHWP) working in the W- band frequency range (75-110 GHz). The device was realised using metallic grids with sub-wavelength anisotropic geometries able to mimic the behaviour of natural birefringent materials. The device was designed using a combination of transmission line codes and finite-element analysis able to achieve phase accuracy down to a fraction of degree. Very accurate intensity and phase measurements were carried out using coherent radiation from a Vector Network Analyser (VNA). The presented device performs better and it is much thinner than previous devices having reduced the number of grids by a factor two and minimised their inductive losses. The new mesh HWP has excellent performances in terms of differential phase-shift flatness and cross-polarisation respectively 180:4 ± 2:9° and -28 dB across a 25% bandwidth.
A broadband metal-mesh half-wave plate for millimetre wave linear polarisation rotation / Pisano, G.; Ng, M. W.; Haynes, V. C.; Maffei, B.. - In: PROGRESS IN ELECTROMAGNETICS RESEARCH M. - ISSN 1937-8726. - 25:(2012), pp. 101-114. [10.2528/PIERM12051410]
A broadband metal-mesh half-wave plate for millimetre wave linear polarisation rotation
Pisano G.;
2012
Abstract
We present a polarisation rotator based on a dielectrically embedded metal Mesh Half Wave Plate (MHWP) working in the W- band frequency range (75-110 GHz). The device was realised using metallic grids with sub-wavelength anisotropic geometries able to mimic the behaviour of natural birefringent materials. The device was designed using a combination of transmission line codes and finite-element analysis able to achieve phase accuracy down to a fraction of degree. Very accurate intensity and phase measurements were carried out using coherent radiation from a Vector Network Analyser (VNA). The presented device performs better and it is much thinner than previous devices having reduced the number of grids by a factor two and minimised their inductive losses. The new mesh HWP has excellent performances in terms of differential phase-shift flatness and cross-polarisation respectively 180:4 ± 2:9° and -28 dB across a 25% bandwidth.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
