Patent ID: 8648596

Claim:
An electron spin resonance (ESR) spectrometer for analyzing the composition of a sample comprising: a radio frequency (RF) or microwave source for generating a carrier signal; a power splitter for splitting the carrier signal into a reference path signal and a signal path signal; a circulator for receiving the signal path signal and a digital phase shifter for receiving the reference path signal; a miniaturized RF microwave cavity resonator, wherein the miniaturized RF microwave cavity resonator receives the signal path signal from the circulator, modulates the signal path signal, and reflects the signal path signal back from the circulator to amplify the signal path signal prior to demodulation; and a pair of mixers, wherein a first mixer demodulates the signal path signal and a second mixer demodulates the reference path signal to produce an absorption spectrum and a dispersion spectrum which are used to generate an ESR spectrum for analyzing the composition of a sample received by the miniaturized RF microwave cavity resonator; wherein the ESR spectrum represents a magnetic susceptibility of the sample causing a variation in a resonant frequency of and reflected signal from the miniaturized RF microwave cavity resonator.