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US 10,209,353 B2Granted
Bandwidth enhancement beamforming
AssigneeSRC, Inc.
InventorDaniel D. Thomas, Jr.
Life of this patent
Estimating the term…
Abstract
A system and method for phased-array radar that is capable of accurate phase-only steering at any unambiguous angle is provided. In various embodiments, system and method that compensates for the varying effective element spacing of phased array radar, which occurs as a result of transmitting a wideband signal with phase shifters operating at a fixed phase, by interpolating and resampling across all elements, per frequency, to generate a desired effective spacing between the elements.
Claims18
A method for narrowing the beamwidth of a wideband phased array radar system, comprising the steps of:
- receiving a plurality of signals from a plurality of antenna elements having a predetermined spacing, wherein each signal comprises a plurality of frequencies;
- digitizing the plurality of received signals;
- inputting a portion of each of the digitized received signals from each element into a DFT processing module and receiving, for each signal, a plurality of frequency bins, each having a complex value and a frequency value, wherein the frequency bins above a reference frequency will exhibit an effective spacing that is smaller than the predetermined spacing, wherein the frequency bins below the reference frequency will be exhibit an effective spacing that is larger than the predetermined spacing;
- creating a plurality of interpolated complex values from the complex values of the frequency bins having the same frequency value from each element;
- and
- sampling the interpolated complex values such that the effective spacing at frequency bins higher than the reference frequency is increased and the effective spacing at frequency bins lower than the reference is decreased, such that a spatial resolution at the frequency value of the frequency bins interpolated is a desired fixed fraction of a wavelength of the signal at the frequency value of the frequency bins interpolated and the beamwidth of the wideband phased array radar system is narrowed.
3 more elements
A method for narrowing the beamwidth of a wideband phased array radar system, comprising the steps of:
- generating a plurality of digital signals comprising a plurality of frequencies;
- inputting the plurality of digital signals to a DFT processing module and receiving, for each signal, a plurality of frequency bins, each having a complex value and a frequency value, wherein the frequency bins above a reference frequency will exhibit an effective spacing that is smaller than the predetermined spacing, wherein the frequency bins below the reference frequency will be exhibit an effective spacing that is larger than the predetermined spacing;
- creating a plurality of interpolated complex values from the complex values of the frequency bins having the same frequency value and from separate signals;
- sampling the interpolated values such that the effective spacing at frequency bins higher than the reference frequency is increased and the effective spacing at frequency bins lower than the reference is decreased, such that the spatial resolution at the frequency value of the frequency bins interpolated is a desired fraction of a wavelength of the signal at the frequency value of the frequency bins interpolated and the beamwidth of the wideband phased array radar system is narrowed;
- phase-steering the time-domain signals;
- and
- transmitting each of the phase-steered time-domain signals from a plurality of antenna elements having a predetermined spacing.
4 more elements
A system for narrowing the beamwidth of a wideband phased array radar system, comprising:
- an analog to digital converter configured to digitize a plurality of signal values received from a plurality of antenna elements having a predetermined spacing, wherein each of the signal values comprises a plurality of frequencies;
- a DFT processing module configured to receive a portion of the digitized signal from each antenna element and to output, for each signal, a plurality of frequency bins, each having a complex value and a frequency value, wherein the frequency bins above a reference frequency will exhibit an effective spacing that is smaller than the predetermined spacing, wherein the frequency bins below the reference frequency will be exhibit an effective spacing that is larger than the predetermined spacing;
- a frequency-dependent interpolator configured to create a plurality of interpolated complex values from the complex values of the frequency bins having the same frequency value and from separate signals, and configured to sample such that the effective spacing at frequency bins higher than the reference frequency is increased and the effective spacing at frequency bins lower than the reference is decreased, the interpolated values such a spatial resolution at the frequency value of the frequency bins interpolated is a desired fraction of a wavelength of the signal at the frequency value of the frequency bins interpolated and the beamwidth of the wideband phased array radar system is narrowed.
A system for narrowing the beamwidth of a wideband phased array radar system, comprising:
- a signal generator configured to generate a plurality of digital signals comprising a plurality of frequencies;
- a DFT processing module configured to receive a portion of the digitized signal from each antenna element and to output, for each signal, a plurality of frequency bins, each having a complex value and a frequency value wherein the frequency bins above a reference frequency will exhibit an effective spacing that is smaller than the predetermined spacing, wherein the frequency bins below the reference frequency will be exhibit an effective spacing that is larger than the predetermined spacing;
- a frequency-dependent interpolator configured to create a plurality of interpolated values from the complex values of the frequency bins having the same frequency value and from separate signals, and configured to sample the interpolated values such that the effective spacing at frequency bins higher than the reference frequency is increased and the effective spacing at frequency bins lower than the reference is decreased, such that the spatial resolution at the frequency value of the frequency bins interpolated is a desired fraction of a wavelength of the signal at the frequency value of the frequency bins interpolated and the beamwidth of the wideband phased array radar system is narrowed;
- a phase-steered digital beamformer configured to beam steer using the plurality of sampled interpolated values;
- a plurality of antennas configured to transmit the plurality of beam steered sampled interpolated values.
2 more elements
Dependencies are inferred from the claim text.