Sensor

Abstract

A sensor measurement device includes: an impedance analyzer to determine an impedance of a sample; a first antenna configured to generate electromagnetic radiation having a first wavelength; an impedance-matching device, positioned in a radiation path between the first antenna and the sample, to receive the electromagnetic radiation from the first antenna and transmit electromagnetic radiation of the first wavelength into the sample, the impedance-matching device comprising a metasurface including: a substrate having a thickness no greater than the first wavelength of the electromagnetic radiation; and a plurality of elements supported by the substrate, wherein: the plurality of elements are spaced apart from one another across the substrate, each element has a first dimension no greater than the first wavelength of the electromagnetic radiation, and at least two elements of the plurality of elements differ in one or more of shape or size; and a second antenna configured to receive the electromagnetic radiation from the sample.

What is claimed is: 
     
         1 . A sensor measurement device comprising:
 An impedance analyzer to determine an impedance of a sample;   a first antenna configured to generate electromagnetic radiation having a first wavelength;   an impedance-matching device, positioned in a radiation path between the first antenna and the sample, to receive the electromagnetic radiation from the first antenna and transmit electromagnetic radiation of the first wavelength into the sample, the impedance-matching device comprising a metasurface including:
 a substrate having a thickness no greater than the first wavelength of the electromagnetic radiation; and 
 a plurality of elements supported by the substrate, wherein:
 the plurality of elements are spaced apart from one another across the substrate, 
 each element has a first dimension no greater than the first wavelength of the electromagnetic radiation, and 
 at least two elements of the plurality of elements differ in one or more of shape or size; and 
 
   a second antenna configured to receive the electromagnetic radiation from the sample,   wherein one or both of the first antenna and the impedance-matching device are tunable based on the impedance of the sample to reduce an impedance mismatch along the radiation path.   
     
     
         2 . The sensor measurement device of  claim 1 , wherein the sample comprises a biological sample. 
     
     
         3 . The sensor measurement device of  claim 1 , wherein the metasurface is configured to impose a specific phase and amplitude change along an incident wave of the electromagnetic radiation. 
     
     
         4 . The sensor measurement device of  claim 1 , wherein, in the impedance-matching device, the first dimension is the direction for propagation of the electromagnetic radiation. 
     
     
         5 . The sensor measurement device of  claim 1 , wherein, in the impedance-matching device, at least one of the plurality of elements has an irregular shape. 
     
     
         6 . The sensor measurement device of  claim 1 , wherein the sample is bound by a container, and wherein the impedance-matching device is configured to transmit the electromagnetic radiation of the first wavelength into the sample from a position outside the container. 
     
     
         7 . The sensor measurement device of  claim 1 , wherein, in the impedance-matching device, at least a subset of the plurality of elements are arranged in an irregular array. 
     
     
         8 . The sensor measurement device of  claim 1 , wherein, in the impedance-matching device, the plurality of elements are arranged in an irregular array. 
     
     
         9 . The sensor measurement device of  claim 1 , wherein, in the impedance-matching device, the substrate is a dielectric and the plurality of elements are conductive. 
     
     
         10 . The sensor measurement device of  claim 1 , wherein, in the impedance-matching device, the substrate is conductive and the plurality of elements are a dielectric. 
     
     
         11 . The sensor measurement device of  claim 1 , wherein, in the impedance-matching device, the plurality of elements are collectively arranged to resonate at the first wavelength of the electromagnetic radiation. 
     
     
         12 . The sensor measurement device of  claim 11 , wherein the impedance-matching device further comprises an additional metasurface coupled to the metasurface, wherein the additional metasurface comprises:
 a substrate comprising a thickness no greater than a second wavelength of the electromagnetic radiation; and   a plurality of elements supported by the substrate, wherein:
 each element has a first dimension no greater than a second wavelength of the electromagnetic radiation; 
 at least two elements of the plurality of elements are non-identical; 
 the additional metasurface is arranged, in cooperation with the metasurface, to resonate at a second wavelength of the electromagnetic radiation; and 
 the first wavelength is different from the second wavelength. 
   
     
     
         13 . The sensor measurement device of  claim 12 , wherein the additional metasurface shapes at least one of an amplitude or phase of the electromagnetic radiation. 
     
     
         14 . The sensor measurement device of  claim 1 , further comprising an electronic calliper arranged to determine a distance between the first antenna and the second antenna. 
     
     
         15 . The sensor measurement device of  claim 1 , wherein one or both of the first antenna and the impedance-matching device comprise a tunable component including one or more of a varactor or a variable resister. 
     
     
         16 . The sensor measurement device of  claim 1 , wherein:
 the sample comprises blood;   the sensor measurement device is arranged to measure a blood glucose level; and   the sensor measurement device is wearable on at least one of a hand, a foot, an ear, or a lip.   
     
     
         17 . The sensor measurement device of  claim 1 , wherein the first antenna, the impedance-matching device, and the second antenna are physically associated. 
     
     
         18 . The sensor measurement device of  claim 1 , further comprising a second impedance-matching device arranged between the sample and the second antenna to transmit electromagnetic radiation of the first wavelength from the sample to the second antenna, the second impedance-matching device comprising a metasurface including:
 a substrate having a thickness no greater than the first wavelength; and   a plurality of elements supported by the substrate, wherein:
 the plurality of elements are spaced apart from one another across the substrate; 
 each element has a first dimension no greater than the first wavelength, and 
 at least two elements of the plurality of elements differ in one or more of shape or size. 
   
     
     
         19 . A method of coupling electromagnetic radiation into a sample using a sensor measurement device, the sensor measurement device comprising:
 an impedance analyzer to determine an impedance of a sample;   a first antenna configured to generate electromagnetic radiation having a first wavelength;   an impedance-matching device, positioned in a radiation path between the first antenna and the sample, to receive the electromagnetic radiation from the first antenna and transmit electromagnetic radiation of the first wavelength into the sample, the impedance-matching device comprising a metasurface including:
 a substrate having a thickness no greater than the first wavelength of the electromagnetic radiation; and 
 a plurality of elements supported by the substrate, wherein:
 the plurality of elements are spaced apart from one another across the substrate, 
 each element has a first dimension no greater than the first wavelength of the electromagnetic radiation, and 
 at least two elements of the plurality of elements differ in one or more of shape or size; and 
 
   a second antenna configured to receive electromagnetic radiation from the sample;   the method comprising:
 positioning the sensor measurement device with respect to the sample such that the first antenna is disposed on a first side of the sample and the second antenna is disposed on a second side of the sample; 
 determine an impedance of a sample; 
 tuning one or both of the first antenna or the impedance-matching device based on the determined impedance to reduce an impedance mismatch along the radiation path; 
 providing electromagnetic radiation having the first wavelength from the first antenna to the impedance-matching device; 
 transmitting, by the impedance-matching device, electromagnetic radiation having the first wavelength from the first antenna into the sample; 
 receiving, by the second antenna, electromagnetic radiation from the sample; and 
   characterizing the sample based on the received electromagnetic radiation.   
     
     
         20 . A method for designing an impedance-matching device for a sensor measurement device, the sensor measurement device comprising:
 a first antenna configured to generate electromagnetic radiation having a first wavelength;   the impedance-matching device, positioned in a radiation path between the first antenna and a test sample, to receive the electromagnetic radiation from the first antenna and transmit the electromagnetic radiation into the test sample, the impedance-matching device comprising a metasurface including:
 a substrate having a thickness no greater than the first wavelength of the electromagnetic radiation; and 
 a plurality of elements supported by the substrate, wherein:
 the plurality of elements are spaced apart from one another across the substrate, 
 each element has a first dimension no greater than the first wavelength of the electromagnetic radiation, and 
 at least two elements of the plurality of elements differ in one or more of shape or size; and 
 
   a second antenna configured to receive electromagnetic radiation from the sample;   the method comprising:
 positioning the first antenna on a first side of the test sample and the second antenna on a second side of the test sample; 
 determining an impedance of the test sample; 
 calculating a sheet impedance for the metasurface that will couple the electromagnetic radiation of the first wavelength into the sample with maximum transmission; and 
 using analytical modelling to design the plurality of elements of the metasurface such that, when the plurality of elements are combined together in a pattern, cause the metasurface to have the calculated sheet impedance.