A broadband microwave radiometer using correlation technique

A broadband microwave radiometer of the differential type has been designed by adopting a correlation scheme with a quadrature hybrid coupler (QHC) and without devices that limit the radiometer bandwidth. We have confirmed its usefulness over 6-12.4 GHz by experimental tests. The correlator used in the radiometer offers in-phase and quadrature-phase outputs. The advantage of this correlator has been investigated.