# US 11,029,353 B2 · Capture of time varying electric field through synchronized spatial array of field effect transistors > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,029,353 B2 - Document ID: US11029353B2 - Status: Granted - Kind: B2 - Application number: 16/104,993 - Filed: 2018-08-20 - Published: 2020-02-20 - Granted: 2021-06-08 - Earliest claimed: 2018-08-20 - Assignees: The United States of America as represented by the Secretary of the Army - Applicants: U.S. Army Research Laboratory - Inventors: Justin L. Shumaker; Geoffrey A. Slipher - Web page: https://patentgrep.com/patent/US11029353B2 ## CPC - G01R 29/0878: {Sensors; antennas; probes; detectors (wave guide measuring sections G01R1/24)} - G01R 29/0814: {Field measurements related to measuring influence on or from apparatus, components or humans (EMC, EMI and similar testing in general G01R31/001), e.g. in ESD, EMI, EMC, EMP testing, measuring radiation leakage; detecting presence of micro- or radiowave emitters; dosimetry; testing shielding; measurements related to lightning} - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract Sensing a time varying electric field includes a device or system including a spatial sensor array having one or more transistors, a circuit including a resistor connected to each of the transistors, an analog-to-digital converter (ADC) to each circuit which convert an analog voltage outputs to digital form, and an antenna to each of the transistors. The antennas sense the time varying electric field and modulate current through their respective transistors. The spatial sensor array may be stationary or in motion during the sensing. ## Claims ### Claim 1 A method for sensing a time varying electric field, the method comprising: providing a spatial sensor array including a plurality of circuits, each circuit comprising: an antenna configured to receive an RF signal and output an electrical current; a transistor connected to the antenna; and a resistor connected to the transistor; sensing a time varying electric field with the antennas of the circuits; modulating current through the transistors of the circuits; converting an analog voltage output of each of the circuits to digital form; and synchronously capturing the digital output of the circuits in the spatial sensor array as a frame without additional amplification means, wherein the spatial sensor array is stationary or in motion during the sensing. ### Claim 2 (depends on 1) The method of claim 1, wherein the transistors of the circuits comprise a junction gate field effect transistor (JFET) or a metal-oxide semiconductor field effect transistor (MOSFET). ### Claim 3 (depends on 1) The method of claim 1, wherein the dynamic range of electric fields sensed ranges from 102 V/m to 108 V/m. ### Claim 4 (depends on 1) The method of claim 1, further comprising: adjusting the sensitivity to electric fields by changing one or more following: the length of the antenna, operating characteristics of the one or more transistors, and/or the selection of an analog digital converter (ADC) also connected to each circuit. ### Claim 5 (depends on 1) The method of claim 1, wherein the frame rate is 50 KHz. ### Claim 6 A device for sensing a time varying electric field, the device comprising: a spatial sensor array comprising a plurality of circuits, each circuit comprising: an antenna configured to receive an RF signal and output an electrical current; a transistor connected to the antenna; a resistor connected to the transistor; an analog-to-digital converter (ADC) connected to the resistor; and a processor configured to synchronously capture the digital output of the circuits in the spatial sensor array as a frame and process the captured digital output, wherein each antenna senses the time varying electric field and modulate current through the transistor it is connected to, and wherein the spatial sensor array is to be stationary or in motion during the sensing. ### Claim 7 (depends on 6) The device of claim 6, wherein the transistors of the circuits comprise a junction gate field effect transistor (JFET) or a metal-oxide semiconductor field effect transistor (MOSFET). ### Claim 8 (depends on 6) The device of claim 6, wherein the dynamic range of the device for sensing electric fields ranges from 102 V/m to 108 V/m. ### Claim 9 (depends on 6) The device of claim 6, wherein the sensitivity of the device for sensing electric fields is adjusted by changing one or more following: the length of the antenna, operating characteristics of the one or more transistors, and/or the selection of the ADC(s). ### Claim 10 (depends on 6) The device of claim 6, wherein, in each of the circuits, (i) the source of each transistor is connected to a voltage source and the drain of each transistor is connected to the resistor which is also connected to ground; or (ii) the source of each transistor is connected to ground and the drain of each transistor is connected to the resistor which is also connected to a voltage source. ### Claim 11 (depends on 6) The device of claim 6, wherein the spatial array comprises: (i) a plurality of antennas arranged in a one dimensional (1D) spatial array, each of the antennas connected to a single transistor; or (ii) a plurality of antennas arranged in a two dimensional (2D) spatial array, with each of the antennas connected to a single transistor. ### Claim 12 (depends on 11) The device of claim 11, wherein each antenna forms an individual pixel of the device. ### Claim 13 (depends on 6) The device of claim 6, wherein the frame rate is 50 KHz. ### Claim 14 (depends on 6) The device of claim 6, wherein each circuit comprises: a single resistor, a single power connection, and a single ground connection. ### Claim 15 (depends on 6) The device of claim 6, wherein the processor is configured to synchronously capture the digital output of the circuits in the spatial sensor array as a frame without additional amplification means. ### Claim 16 (depends on 6) A method of forming the device of claim 6, comprising: patterning the circuits on a substrate using photolithography. ### Claim 17 A system for sensing a time varying electric field, the system comprising: a spatial sensor array comprising a plurality of circuits, each circuit comprising: a field effect transistor (FET) connected to the antenna; a resistor connected to the FET; an analog-to-digital converter (ADC) connected to the resistor; and an antenna connected to the FET, wherein the antenna is to sense the time varying electric field and modulate current through the FET, wherein the spatial sensor array is to be stationary or in motion during the sensing; and a computer processor configured to synchronously capture the digital output of the circuits in the spatial sensor array as a frame without additional amplification means and process the captured digital output. ### Claim 18 (depends on 17) The system of claim 17, wherein the dynamic range of the system for sensing electric fields ranges from 102 V/m to 108 V/m. ### Claim 19 (depends on 17) The system of claim 17, wherein the sensitivity of the system for sensing electric fields is adjusted by changing one or more following: the length of the antenna, operating characteristics of the one or more FETs, and/or the selection of the ADCs. ### Claim 20 (depends on 17) The system of claim 17, further comprising a memory which stores digital output of the ADCs for a given time sequence.