# US 11,309,870 B2 · Field effect transistor (FET) configured to phase shift a radar signal using first and second variable voltages applied to a gate and a back gate of the FET > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,309,870 B2 - Document ID: US11309870B2 - Status: Granted - Kind: B2 - Application number: 16/945,438 - Filed: 2020-07-31 - Published: 2022-02-03 - Granted: 2022-04-19 - Earliest claimed: 2020-07-31 - Assignees: GM Global Technology Operations LLC - Applicants: GM Global Technology Operations LLC - Inventors: Jongchang Kang; Ara Kurdoghlian; Mehran Mokhtari; Igal Bilik - Web page: https://patentgrep.com/patent/US11309870B2 ## CPC - H03H 11/20: Two-port phase shifters providing an adjustable phase shift - H01P 1/18: Phase-shifters (H01P1/165 takes precedence) - H01P 1/185: using a diode or a gas filled discharge tube - H01Q 3/36: with variable phase-shifters - H03H 11/16: Networks for phase shifting - H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P) - H01P: WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE (operating at optical frequencies G02B) - H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72) ## Abstract The present application relates to a method and apparatus for implementing a radar array including a gate bias source for providing a first variable voltage, a back gate well control for providing a second variable voltage, and a field effect transistor having a drain, a source, a gate and a back gate well control, the field effect transistor being further configured to couple an alternating current radar signal between the drain and the source and to adjust a phase of the alternating current radar in response to first variable voltage applied to the gate and the second variable voltage applied to the back gate well control. ## Claims ### Claim 1 A radar array comprising: a gate bias source configured for providing a first variable voltage; a back gate bias source configured for providing a second variable voltage; and a field effect transistor having a drain, a source, a gate and a back gate well control, the field effect transistor configured to couple an alternating current radar signal between the drain and the source and to adjust a phase of the alternating current radar signal in response to the first variable voltage being applied to the gate and the second variable voltage being applied to the back gate well control. ### Claim 2 (depends on 1) The radar array of claim 1 further including a substrate and wherein the field effect transistor is formed within the substrate and wherein the field effect transistor has a drain to body capacitance between the drain and the substrate and wherein adjusting the first variable voltage and the second variable voltage modifies the drain to body capacitance. ### Claim 3 (depends on 1) The radar array of claim 1 further including a preamplifier configured for adjusting a magnitude of the alternating current radar signal and configured for coupling the alternating current radar signal to the source. ### Claim 4 (depends on 1) The radar array of claim 1 further including an amplifier configured for receiving the radar signal from the drain, adjusting a magnitude of the radar signal and configured for coupling the radar signal to a radar antenna. ### Claim 5 (depends on 1) The radar array of claim 1 wherein the radar array includes a plurality of antennas and wherein each of the plurality of antennas is coupled to a respective one of a plurality of phase shifters. ### Claim 6 (depends on 1) The radar array of claim 1 wherein the alternating current radar signal is a millimeter wave radar signal. ### Claim 7 (depends on 1) The radar array of claim 1 further including an insulator well formed between the field effect transistor and a substrate and wherein the insulator well has an insulator well to substrate capacitance forming a portion of a drain to substrate capacitance and wherein the second variable voltage applied at the back gate well control alters the insulator well to substrate capacitance. ### Claim 8 (depends on 1) The radar array of claim 1 wherein the second variable voltage is applied to the back gate well control via a radio frequency choke resistor. ### Claim 9 A method of altering a phase of a radar signal by a field effect transistor formed on a substrate comprising: receiving the radar signal at a source of the field effect transistor; applying a first variable voltage to a gate of the field effect transistor; applying a second variable voltage to a back gate well control such that the phase of the radar signal is adjusted to a desired phase to generate an adjusted radar signal; and transmitting the adjusted radar signal having the desired phase from a drain of the field effect transistor. ### Claim 10 (depends on 9) The method of altering a phase of a radar signal by a field effect transistor formed on a substrate of claim 9 wherein varying the second variable voltage varies a drain to body capacitance between the drain and the substrate. ### Claim 11 (depends on 9) The method of altering a phase of a radar signal by a field effect transistor formed on a substrate of claim 9 further including adjusting a magnitude of the radar signal by using a preamplifier and coupling the radar signal to the source by using the preamplifier. ### Claim 12 (depends on 9) The method of altering a phase of a radar signal by a field effect transistor formed on a substrate of claim 9 further including adjusting, by using an amplifier, a magnitude of the adjusted radar signal and coupling the adjusted radar signal to a radar antenna by using the amplifier. ### Claim 13 (depends on 9) The method of altering a phase of a radar signal by a field effect transistor formed on a substrate of claim 9 wherein the field effect transistor is one of a plurality of field effect transistors and wherein the plurality of field effect transistors form a portion of a radar array. ### Claim 14 (depends on 9) The method of altering a phase of a radar signal by a field effect transistor formed on a substrate of claim 9 wherein the radar signal is a millimeter wave radar signal. ### Claim 15 (depends on 9) The method of altering a phase of a radar signal by a field effect transistor formed on a substrate of claim 9 wherein the field effect transistor is formed on an insulator well formed within the substrate and wherein the insulator well has an insulator well to substrate capacitance that forms a portion of a drain to substrate capacitance and wherein the second variable voltage applied at the back gate well control alters the insulator well to substrate capacitance. ### Claim 16 (depends on 9) The method of altering a phase of a radar signal by a field effect transistor formed on a substrate of claim 9 wherein the second variable voltage is applied to the back gate well control via a switched DC bias source. ### Claim 17 A solid state radar array comprising: a first radar signal channel including a first antenna, a first amplifier, and a first bandpass filter; and a second radar signal channel including a second antenna, a second amplifier, a second bandpass filter, and a phase shifter wherein the phase shifter includes a field effect transistor having a drain, a source, a gate and a back gate well control, the field effect transistor being configured to couple a first alternating current radar signal between the drain and the source and to adjust a phase of the first alternating current radar signal in response a first variable voltage from a gate bias source applied to the gate and a second variable voltage from a back gate control source applied to the back gate well control.. ### Claim 18 (depends on 17) The solid state radar array of claim 17 wherein the first antenna is configured to receive a second alternating current radar signal and the second antenna is configured to receive the first alternating current radar signal and wherein the phase shifter is configured to adjust the phase of the first alternating current radar signal to match a phase of the second alternating current radar signal. ### Claim 19 (depends on 17) The solid state radar array of claim 17 wherein the first antenna is configured to transmit a second alternating current radar signal and the second antenna is configured to transmit the first alternating current radar signal and wherein the phase shifter is configured to adjust the phase of the first alternating current radar signal to alter a directivity of the solid state radar array. ### Claim 20 (depends on 17) The solid state radar array of claim 17 wherein the first amplifier, the first bandpass filter; the second amplifier, the second bandpass filter and the phase shifter are formed as an integrated circuit.