ESA Antenna Null Steering for Adjacent Satellite Interference

Solution Overview

Problem

Geo-synchronous satellite systems face reduced spectral efficiency due to adjacent satellite interference, which increases operational costs and degrades signal quality, especially in mobile applications where antenna size and beam pattern adjustments are limited.

Innovation Solution

The implementation of an electronically scanned array (ESA) antenna with sub-arrays configured to sample and remove interfering signals, utilizing digital signal processing to analyze and cancel out adjacent satellite interference by creating nulls in the gain pattern response.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an oversized antenna is used to provide good spectral efficiency, then signal quality improves, but installation footprint and weight increase significantly

Engineering Contradiction:

Improvesignal qualityVSAvoidantenna weight

Core Design Contradiction:

ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent implements dynamic beam pattern adjustment through electronic phasing of antenna elements, allowing the antenna to adapt its radiation pattern in real-time to track satellites and reject interference without mechanical movement or size increase

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent replaces mechanical phased array systems with electronically controlled phase shifters and signal processors, eliminating the need for large mechanical structures while achieving the same beam forming and interference rejection capabilities

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of manufacture

If a fixed beam pattern antenna is used, then manufacturing is simpler, but the ability to adjust and cancel adjacent satellite interference is lost

Engineering Contradiction:

Improveantenna manufacturing simplicityVSAvoidinterference cancellation capability

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic beam pattern adjustment through electronic phasing of antenna elements, allowing the antenna to adapt its radiation pattern in real-time to track satellites and reject interference without mechanical movement or size increase

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent uses variable phase shifters and amplitude controllers to dynamically change the electrical parameters of the antenna array, enabling real-time beam steering and null placement to adapt to changing satellite positions and interference conditions

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If separate apertures are used to handle different aspect ratios, then coverage at different latitudes improves, but performance near the equator deteriorates when the narrow dimension is aligned with the satellite arc

Engineering Contradiction:

Improvelatitude coverageVSAvoidsignal quality near equator

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent implements dynamic beam pattern adjustment through electronic phasing of antenna elements, allowing the antenna to adapt its radiation pattern in real-time to track satellites and reject interference without mechanical movement or size increase

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent creates a universal antenna system that can operate effectively at all latitudes including the equator by using electronic beam forming to adapt to different satellite positions and geometries, eliminating the need for separate aperture configurations

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 solution enhances spectral efficiency by dynamically adjusting the antenna's gain pattern to exclude interfering signals, improving the carrier-to-noise-plus-interference ratio and reducing operational costs in mobile satellite communication systems.

Implementation Method 1

The gain pattern response of the ESA is configured with nulls where interfering adjacent satellite signals would be received

Methodology Applied

Scientific EffectBeam forming:

Implementation Method 2

sub-arrays of the ESA are configured to sample interfering adjacent satellite signals. The sampled signal is then removed from the primary single received by the ESA

Methodology Applied

Scientific EffectSignal cancellation:

Data Source

PatentUS10211510B1Adjacent signal interference mitigation

Publication Date: 2019.02.19 ROCKWELL COLLINS INC

AI summary

A satellite system includes directional antenna with a gain pattern response having nulls where interfering adjacent satellite signals would be received. Using an electronically scanned array (ESA), sub-arrays of the ESA sample interfering adjacent satellite signals and then filter the sampled signals from the primary single received by the ESA. Digital signal processing increases the accuracy of the filtering process by analyzing the interfering adjacent satellite signal to determine the angle-of-arrival of the signal.