# US 10,374,663 B2 · Digital dithering for reduction of quantization errors and side-lobe levels in phased array antennas > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,374,663 B2 - Document ID: US10374663B2 - Status: Granted - Kind: B2 - Application number: 15/396,070 - Filed: 2016-12-30 - Published: 2018-07-05 - Granted: 2019-08-06 - Earliest claimed: 2016-12-30 - Assignees: Hughes Network Systems, LLC - Applicants: Hughes Network Systems, LLC - Inventors: Thomas Jackson; Hamad Alsawaha; Bingqian Lu; Peter Hou; Yilin Mao - Web page: https://patentgrep.com/patent/US10374663B2 ## CPC - H04B 7/01: Reducing phase shift - H01Q 3/26: varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture ({H01Q3/12,} H01Q3/22, H01Q3/24 take precedence) - H01Q 3/38: the phase-shifters being digital - H01Q 21/22: Antenna units of the array energised non-uniformly in amplitude or phase, e.g. tapered array or binomial array - H04B 7/18528: {Satellite systems for providing two-way communications service to a network of fixed stations, i.e. fixed satellite service or very small aperture terminal [VSAT] system} - H04B: TRANSMISSION - H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72) ## Abstract Systems and methods disclosed herein provide techniques for reducing quantization errors and side lobe levels in phased array antennas. The states of a quantized phase shifter of a phased array antenna may be dithered to achieve a time-averaged value that reduces quantization errors. By rapidly switching between the different states of the quantized phase shifter, a time-average value close to a desired phase state may be achieved with a low resolution phase shifter. ## Claims ### Claim 1 A method, comprising: receiving an input signal at a quantized phase shifter of a phased array antenna; obtaining a time averaged, phased shifted signal that reduces a quantization error of the phase shifter, wherein obtaining the time averaged phase shifted signal comprises switching between two phase states of the quantized phase shifter a plurality of times to obtain a time-averaged value of a state of the quantized phase shifter that is between values of the two phase states; and outputting the time averaged, phase shifted signal to an antenna element circuit of the phased array antenna. ### Claim 2 (depends on 1) The method of claim 1, wherein switching between the two phase states of the quantized phase shifter comprises switching between the two phase states of the quantized phase shifter at a rate greater than the highest symbol rate of an adjacent satellite. ### Claim 3 (depends on 2) The method of claim 2, wherein switching between the two phase states of the quantized phase shifter comprises switching between the two phase states of the quantized phase shifter at a rate at least four times greater than the highest symbol rate of an adjacent satellite. ### Claim 4 (depends on 1) The method of claim 1, wherein the time averaged, phase shifted signal is obtained using at least linear interpolation or accumulator interpolation. ### Claim 5 (depends on 1) The method of claim 1, wherein obtaining the time averaged, phase shifted signal comprises: obtaining an error signal by comparing an output phase to a required phase; and providing the error signal as an input to an integrator to obtain an integrated signal. ### Claim 6 (depends on 5) The method of claim 5, wherein obtaining the time averaged, phase shifted signal comprises: unwrapping the output phase of the integrated signal to obtain an unwrapped signal; and quantizing the unwrapped signal. ### Claim 7 (depends on 1) The method of claim 1, wherein the quantized phase shifter is 1-bit or 2-bit phase shifter. ### Claim 8 (depends on 1) The method of claim 1, wherein the quantized phase shifter provides a constant phase shift of an input signal over a frequency. ### Claim 9 (depends on 1) The method of claim 1, wherein the quantized phase shifter provides a true time delay of an input signal. ### Claim 10 (depends on 1) The method of claim 1, wherein switching between the two phase states of the quantized phase shifter a plurality of times to obtain a time-averaged value of a state of the quantized phase shifter that is between values of the two phase states, comprises: using pulse width modulation duty cycles corresponding to the two phase states to obtain the time-averaged value. ### Claim 11 A phased array antenna, comprising: a plurality of quantized phase shifters; a controller to switch between the phase states of each of the plurality of quantized phase shifters to obtain a time-averaged, phase shifted signal from each of the plurality of quantized phase shifters, wherein the controller is configured to obtain the time-averaged, phase shifted signal for each of the plurality of quantized phase shifters by switching between two phase states of the quantized phase shifter a plurality of times to obtain a time-averaged value of a state of the quantized phase shifter that is between values of the two phase states; and a plurality of antenna elements, wherein each of the plurality of antenna elements is to receive the time-averaged, phase shifted signal from a respective one of the plurality of quantized phase shifters. ### Claim 12 (depends on 11) The phased array antenna of claim 11, wherein each of the plurality of quantized phase shifters is 1-bit or 2-bit phase shifter. ### Claim 13 (depends on 11) The phased array antenna of claim 11, wherein each of the plurality of quantized phase shifters provides a constant phase shift of an input signal over a frequency. ### Claim 14 (depends on 11) The phased array antenna of claim 11, wherein each of the plurality of quantized phase shifters provides a true time delay of an input signal. ### Claim 15 (depends on 11) The phased array antenna of claim 11, wherein the phased array antenna is a phased array antenna of a very small aperture terminal (VSAT). ### Claim 16 (depends on 11) The phased array antenna of claim 11, wherein the phased array antenna is a phased array antenna of a satellite. ### Claim 17 (depends on 11) The phased array antenna of claim 11, wherein the controller is to obtain the time-averaged, phase shifted signal of each of the plurality of quantized phase shifters using at least linear interpolation or accumulator interpolation. ### Claim 18 A method, comprising: receiving an RF communication signal at each of a plurality of antenna elements of a phased array antenna; outputting a signal from an antenna element to a quantized phase shifter; and obtaining a time averaged, phased shifted signal that reduces a quantization error of the phase shifter, wherein obtaining the time averaged phase shifted signal comprises switching between two phase states of the quantized phase shifter a plurality of times to obtain a time-averaged value of a state of the quantized phase shifter that is between values of the two phase states. ### Claim 19 (depends on 18) The method of claim 18, wherein obtaining the time averaged, phased shifted signal comprises: obtaining an error signal by comparing an output phase to a required phase; and providing the error signal as an input to an integrator to obtain an integrated signal. ### Claim 20 (depends on 18) The method of claim 18, wherein the time averaged, phase shifted signal is obtained using linear interpolation or accumulator interpolation. ### Claim 21 (depends on 18) The method of claim 18, further comprising: amplifying the RF communication signal received at each of the plurality of antenna elements using a low noise amplifier.