Analysis and performance assessment of a real-time correction pseudo-correlation microwave radiometer for medical applications

Abstract

A new configuration of a pseudo-correlation type radiometer is proposed for a microwave biomedical application, such as diabetic foot neuropathy. The new approach as well as its simulated performance are thoroughly assessed using commercial off-the-shelf components and custom designed subsystems. We configured a pseudo-correlation receiver, centred at 3.5 GHz, to validate the proposal, comparing its simulated response with a measured alternative based on a 90º hybrid coupler pseudo-correlation prototype. We custom designed a balanced Wilkinson power divider and a 180º hybrid coupler to fulfil the receiver's requirements. The proposed configuration demonstrated an improved noise temperature response. The main advantage is to enable the recalibration of the receiver through simultaneous measurable output signals, proportional to each input signal, as well as the correlated response between them.