Antenna-grating coupled sensing system for clutter reduction during evaluation of a status of a material

A sensing system for evaluating a status of a material, comprising:

• a. an antenna configured to transmit a first radiofrequency signal, onto a surface of said material to be evaluated, and to receive a second radiofrequency signal received from said surface of said material to be evaluated, wherein said antenna has an impedance at a closest point to said material that substantially matches an impedance of said surface of said material to be evaluated, and wherein said antenna is placed contiguously to said surface of said material;
• b. a grating structure comprising a plurality of elements electrically conductive at a frequency of operation of said first radiofrequency signal and at a frequency of operation of said second radiofrequency signal, wherein at least two of said plurality of elements are disposed substantially parallel to each other next to said surface of said material to be evaluated;
• c. a coupling mechanism to couple said antenna to said at least one of said elements of said grating;
• wherein said antenna and at least one of said elements of said grating are properly coupled to reduce a plurality of signal reflections and a plurality of signal ringing of said first radiofrequency signal and said second radiofrequency signal to reduce a level of clutter otherwise present in said antenna by at least 10 dB, by coupling said at least one of said elements of said grating to at least a part of said antenna in a manner selected from a group consisting of physically and by placing said antenna within less than five percent of a wavelength, corresponding to a maximum frequency of said first radiofrequency signal, from said at least one of said elements of said grating, and wherein said coupling mechanism couples, over a range of motion, said antenna to said at least one of said elements of said grating over a range of spacing gaps between said antenna and said at least one of said elements of said grating.