# US 11,121,896 B1 · Low-resolution, low-power, radio frequency receiver > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,121,896 B1 - Document ID: US11121896B1 - Status: Granted - Kind: B1 - Application number: 17/103,152 - Filed: 2020-11-24 - Granted: 2021-09-14 - Earliest claimed: 2020-11-24 - Assignees: AT&T Intellectual Property I, L.P.; University of Notre Dame du Lac - Applicants: AT&T Intellectual Property I, L.P.; University of Notre Dame du Lac - Inventors: Ralf Bendlin; Aditya Chopra; Bertrand Martyn Hochwald; Nicholas Joseph Estes; Jonathan David Chisum; Kang Gao - Web page: https://patentgrep.com/patent/US11121896B1 ## CPC - H04L 27/22: Demodulator circuits; Receiver circuits - H04B 7/0413: MIMO systems - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04B: TRANSMISSION ## Abstract Aspects of the subject disclosure may include, for example, receiving a radio frequency (RF) signal having a carrier wave component that operates at a carrier frequency within a millimeter wave spectrum. The RF signal also includes an information component based on a phase shift keying (PSK) modulation of the carrier wave component. A local oscillator (LO) signal is obtained, which includes an LO frequency that approximates the carrier frequency. The received RF signal and the LO signal are combined without using signal multiplication to obtain a first combined output signal. The first combined output signal being detected via a non-linear energy detector to obtain a first detected signal. The first output signal includes information of the information component. Other embodiments are disclosed. ## Claims ### Claim 1 A radio receiver, comprising: a local oscillator (LO) adapted to provide an LO signal that generates a prominent LO frequency that approximates a carrier frequency of a received radio frequency (RF) signal, the received RF signal having a carrier wave component operating at the carrier frequency within a millimeter wave spectrum and an information component, wherein the information component is based on a phase shift keying (PSK) modulation of the carrier wave component; an RF signal combiner comprising: a first RF input port adapted to accept the received RF signal; a second RF input port coupled to the LO; and an output port, wherein the RF signal combiner is adapted to combine, without multiplication, the received RF signal and the LO signal to obtain a first combined output signal; and a non-linear energy detector in communication with the output port and adapted to generate a detected baseband signal based on an amplitude of the first combined output signal, wherein an amplitude of the detected baseband signal corresponds to an in-phase portion of the received RF signal, and wherein the detected baseband signal conveys information of the information component. ### Claim 2 (depends on 1) The radio receiver of claim 1, wherein the non-linear energy detector comprises a current-voltage (I-V) characteristic curve, the detected baseband signal determined according to the I-V characteristic curve. ### Claim 3 (depends on 2) The radio receiver of claim 2, wherein the non-linear energy detector comprises a diode. ### Claim 4 (depends on 2) The radio receiver of claim 2, wherein a power level of the prominent LO frequency is sufficiently low to preserve operation of the non-linear energy detector as a square law device. ### Claim 5 (depends on 1) The radio receiver of claim 1, wherein the received RF signal is obtained via an antenna responsive to illumination of the antenna by a spatially diverse RF signal transmitted from a multiple input multiple output (MIMO) transmitter, wherein phase modulation of the carrier wave component is impressed upon the spatially diverse RF signal by the MIMO transmitter. ### Claim 6 (depends on 1) The radio receiver of claim 1, further comprising a low noise amplifier (LNA) communicatively coupled between an antenna adapted to receive the received RF signal and the RF signal combiner, wherein the LNA is operated in saturation. ### Claim 7 (depends on 1) The radio receiver of claim 1, further comprising: an analog-to-digital converter (ADC) communicatively coupled to the non-linear energy detector, wherein the ADC is adapted to generate a digital signal according to the detected baseband signal. ### Claim 8 (depends on 7) The radio receiver of claim 7, wherein the ADC comprises a comparator adapted to compare the detected baseband signal to a reference value to obtain a comparison result, and wherein the digital signal is obtained according to the comparison result. ### Claim 9 (depends on 8) The radio receiver of claim 8, wherein the reference value comprises a threshold voltage, the digital signal being obtained according to a comparison of the detected baseband signal. ### Claim 10 A multiple input multiple output (MIMO) radio, comprising: a local oscillator (LO) adapted to provide an LO signal that includes an LO frequency that approximates a carrier frequency of a received wireless MIMO signal, the received MIMO signal having a carrier wave component operating at the carrier frequency within a millimeter wave spectrum and an information component, wherein the information component is based on a phase shift keying (PSK) modulation of the carrier wave component; a plurality of radio modules, each adapted to provide a respective low-resolution output signal responsive to the received wireless MIMO signal, each radio module comprising: a respective radio frequency (RF) signal combiner comprising: a RF input port adapted to accept a respective received RF signal responsive to the received wireless MIMO signal received via a wireless channel; a second RF input port coupled to the LO; and an output port, wherein the RF signal combiner is adapted to combine, without multiplication, the received RF signal and the LO signal to obtain a respective combined output signal; a respective envelope detector communicatively coupled to the output port, wherein the respective envelope detector is adapted to detect information modulated onto the received wireless MIMO signal prior to transmission via the wireless channel, to obtain a respective detected baseband signal, wherein an amplitude of the respective detected baseband signal corresponds to an in-phase portion of the received RF signal; and a digital processor communicatively coupled to the plurality of radio modules and adapted to determine an estimate of the information modulated onto the received wireless MIMO signal prior to transmission according to the respective detected baseband signal of each of the plurality of radio modules. ### Claim 11 (depends on 10) The MIMO radio of claim 10, wherein a dimension of a respective radio module is no larger than a maximum dimension of a respective antenna element, such that a size of each radio module is determined according to the maximum dimension of the respective antenna element. ### Claim 12 (depends on 10) The MIMO radio of claim 10, wherein the respective envelope detector comprises a semiconductor junction configured to detect the information modulated onto the received wireless MIMO signal when operating in a non-linear region, and wherein a power level of the LO is sufficiently low to preserve operation of the semiconductor junction as a square law device. ### Claim 13 A method, comprising: receiving a radio frequency (RF) signal to obtain a received RF signal having a carrier wave component operating at a carrier frequency within a millimeter wave spectrum and an information component based on a phase shift keying (PSK) modulation of the carrier wave component; obtaining a local oscillator (LO) signal comprising an LO frequency, wherein the LO frequency approximates the carrier frequency; combining, without multiplication, the received RF signal and the LO signal to obtain a first combined output signal; and detecting, via a non-linear energy detector, an in-phase portion of the first combined output signal to obtain a first detected signal, wherein an amplitude of the first detected signal corresponds to an in-phase portion of the received RF signal, and wherein the first combined output signal comprises information of the information component. ### Claim 14 (depends on 13) The method of claim 13, wherein the received RF signal is a wireless multiple-input-multiple-output (MIMO) signal, further comprising: digitizing the first detected signal to obtain a first digital output signal; and providing the first digital output signal to a digital processor, the digital processor also obtaining a second digital output signal obtained by an antenna from the RF signal at a second location, the digital processor determining an estimate of the information of the information component, the information originating at a remote MIMO transmitter according to the first and second digital output signals. ### Claim 15 (depends on 13) The method of claim 13, wherein the detecting of the in-phase portion of the received RF signal further comprises rectifying, via a semiconductor junction, the first combined output signal. ### Claim 16 (depends on 15) The method of claim 15, wherein an amplitude of the LO signal is sufficiently low to preserve operation of the semiconductor junction as a square law device. ### Claim 17 (depends on 13) The method of claim 13, wherein the combining of the received RF signal and the LO signal comprises a resistive power divider adapted to substantially dissipate out-of-phase portions of the received RF signal. ### Claim 18 (depends on 13) The method of claim 13, further comprising: dividing the received RF signal into substantially equal first and second divided RF signals; and obtaining a quadrature-phase LO signal, wherein a phase difference between the LO signal and the quadrature-phase LO signal is about 90 degrees, wherein the combining, without multiplication, of the received RF signal and the LO signal to obtain the first combined output signal, comprises: combining the first divided RF signal with the LO signal to obtain the first combined output signal, wherein an amplitude of the first combined output signal corresponds to the in-phase portion of the RF signal; and combining the second divided RF signal with the quadrature-phase LO to obtain a second combined output signal, wherein an amplitude of the second combined output signal corresponds to a quadrature-phase portion of the RF signal. ### Claim 19 (depends on 13) The method of claim 13, wherein the combining of the received RF signal and the LO signal further comprises applying the received RF signal and the LO signal to different input ports of a hybrid coupler network, the hybrid coupler network adapted to generate an in-phase output signal and a quadrature-phase output signal. ### Claim 20 (depends on 19) The method of claim 19, wherein the detecting further comprises: detecting, via a first non-linear energy detector, the in-phase output signal to obtain an in-phase detected signal, and detecting, via a second non-linear energy detector, the quadrature-phase output signal to obtain a quadrature-phase detected signal.