Microwave spectrometer having individually adjustable reference and test channels

Claim 1

A SPECTROMETER COMPRISING: A SOURCE FOR PRODUCING AN ELECTROMAGNETIC RADIATION SIGNAL; SAMPLE HOLDING MEANS INCLUDING AN ELEMENT FOR PRODUCING AN EXCITATION FIELD IN A SAMPLE HELD IN THE SAMPLE HOLDING MEANS; DETECTING MEANS PRODUCING AN OUTPUT IN RESPONSE TO APPLICATION OF AN ELECTROMAGNETIC RADIATION SIGNAL THERETO; MEANS INCLUDING SAID SAMPLE HOLDING MEANS AND FORMING A FIRST SIGNAL PATH BETWEEN SAID SOURCE AND SAID DETECTING MEANS FOR APPLYING TO SAID DETECTING MEANS A FIRST ELECTROMAGNETIC RADIATION SIGNAL WHICH IS CHANGED FROM THE ELECTROMAGNETIC RADIATION SIGNAL FROM SAID SOURCE BY THE INTERACTION OF SAID EXCITATION FIELD WITH THE SAMPLE HELD IN SAID SAMPLE HOLDING MEANS; MEANS FORMING A SECOND SIGNAL PATH BETWEEN SAID SOURCE AND SAID DETECTING MEANS FOR APPLYING TO SAID DETECTING MEANS A SECOND ELECTROMAGNETIC RADIATION SIGNAL OF SELECTED MAGNITUDE AND PHASE RELATIVE TO SAID FIRST ELECTROMAGNETIC RADIATION SIGNAL, SAID DETECTING MEANS PRODUCING AN OUTPUT IN RESPONSE TO THE RESULTANT OF ELECTROMAGNETIC RADIATION SIGNALS APPLIED THERETO; AND MODULATING MEANS COUPLED TO THE SAMPLE HOLDING MEANS AND TO THE MEANS FORMING THE SECOND SIGNAL PATH FOR TIME-VARYING THE ELECTROMAGNETIC RADIATION SIGNAL CHANGE PRODUCED BY THE INTERACTION OF SAID EXCITATION FIELD WITH THE SAMPLE HELD IN SAID SAMPLE HOLDING MEANS AND FOR TIME-VARYING SAID SECOND ELECTROMAGNETIC RADIATION SIGNAL, THE SELECTED PARAMETERS OF THE SECOND ELECTROMAGNETIC RADIATION SIGNAL RELATIVE TO CORRESPONDING PARAMETERS OF THE FIRST ELECTROMAGNETIC RADIATION SIGNAL WHICH PROVIDED A SELECTED OUTPUT FROM THE DETECTOR MEANS PROVIDING AN INDICATION OF THE ELECTROMAGNETIC RADIATION SIGNAL CHANGE PRODUCED BY THE INTERACTION OF SAID EXCITATION FIELD WITH THE SAMPLE HELD IN SAID SAMPLE HOLDING MEANS.