AESA Antenna Digital Beamforming Beyond ADC/DAC Sampling Limits

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Solution Overview

Problem

Active electronically scanned array (AESA) antennas are limited by the sampling rates of analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuits, which restrict the number of antennas and spatial resolution, and require complex frequency translation hardware.

Innovation Solution

The AESA system incorporates a processing circuit with DAC circuits, splitter circuits, band pass filter circuits, mixer circuits, and local oscillators to generate digital signals for beamforming, allowing for increased antenna count and spatial resolution without the need for analog frequency translation, using digital beamforming algorithms to steer RF signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the number of antennas in AESA is increased to improve spatial resolution, then spatial resolution is improved, but the sampling rate limitation of ADC/DAC circuits restricts further increase

Engineering Contradiction:

Improvespatial resolutionVSAvoidADC/DAC circuit complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the frequency translation function from analog circuitry and relocates it to the digital domain. By removing the analog frequency translation hardware and implementing beamforming algorithms digitally, the system eliminates the sampling rate bottleneck of ADC/DAC circuits while maintaining the ability to process signals from a large number of antennas, thus improving spatial resolution without being constrained by converter limitations.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical/analog frequency translation system with a digital signal processing system. Instead of using analog mixers and local oscillators to translate frequencies before ADC conversion, the system uses digital beamforming algorithms to perform frequency translation and signal processing in the digital domain after ADC conversion, thereby eliminating the sampling rate constraint on the number of antennas.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If analog frequency translation hardware is used in AESA, then frequency translation is achieved, but hardware complexity increases

Engineering Contradiction:

Improvefrequency translation capabilityVSAvoidfrequency translation hardware

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent substitutes analog frequency translation hardware with digital signal processing. The system uses digital beamforming algorithms implemented on programmable logic devices to perform frequency translation, phase shifting, and beam steering operations that were traditionally accomplished with analog mixers, local oscillators, and phase shifters. This digital approach reduces hardware complexity while maintaining full frequency translation capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements a universal digital beamforming platform that can perform multiple functions including frequency translation, phase shifting, beam steering, and signal processing through software algorithms. The same digital hardware infrastructure supports various operating frequencies and beamforming configurations without requiring dedicated analog frequency translation hardware for each function, thereby reducing overall system complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration enables wider instantaneous bandwidth, increased spatial resolution, and improved jamming suppression by allowing more antennas without additional digital logic or ADC circuits, simplifying hardware and enhancing beamforming capabilities.

Implementation Method 1

Each of the antennas converts the output signal of one of the mixer circuits into an RF signal

Methodology Applied

Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Implementation Method 2

Each of the mixer circuits multiples the frequency of one of the filtered signals by a frequency of a carrier signal received from one of the local oscillators

Methodology Applied

Scientific EffectFrequency mixing: Heterodyne

Data Source

PatentUS20240396579A1Systems And Methods For Electronically Scanned Array Antennas

Publication Date: 2024.11.28 ALTERA CORP

AI summary

An array of antennas includes transmitter and receiver circuits. The transmitter includes a digital-to-analog converter (DAC), splitter and filter circuits, and mixer circuits. The DAC circuit converts a digital signal into an analog signal. The splitter and filter circuits separate frequencies of the analog signal into split signals. The mixer circuits multiply frequencies from the split signals by different frequencies of carrier signals to generate modulated signals that are converted into radio frequency (RF) signals. The receiver includes mixer circuits, a summing circuit, and an analog-to-digital converter (ADC). RF signals are converted into electrical signals. The mixer circuits multiply frequencies from the electrical signals with different frequencies of carrier signals. The outputs of the mixer circuits are summed by the summing circuit to generate a summed signal that is converted to digital by the ADC.