By using an on-chip microwave sensor employing spintronic and spin caloritronic principles, a spintronic technique has been developed for microwave imaging. This novel technique allows microwave fields to be directly rectified on chip into dc voltage signals. This imaging technique does not require complicated and expensive microwave systems to operate, yet it can still electrically detect scattered microwave fields accurately enough to image embedded defects and hidden objects. By varying the experimental setup, apparatuses based on spintronic sensors have been developed for achieving both near- and far-field imaging (at microwave frequencies) as well as for performing on-chip dielectric analysis.