Design and evaluation of medical microwave radiometer for measuring tissue temperature

Medical microwave radiometry is a passive non-invasive technique for measuring tissue temperature gradient in the human body. Design and evaluation of a medical microwave radiometer centered at 1.3 GHz with 330 MHz bandwidth is presented here. An active noise source with noise equivalent temperature of 303 K is used for temperature calibration. Radiometer characterization results are presented for matched load maintained at thermal steady state and hot spot in a tissue phantom. Radiometer measurements recorded using a dielectric loaded waveguide and substrate integrated waveguide (SIW) antenna with a slot demonstrated the ability to measure the temperature gradient at depth.