Radar Antenna Slaving Waveform to ESM Transmissions

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current radar systems for air-ground or air-sea observation and surveillance missions face challenges in integrating radar and Electronic Support Measure (ESM) functions within constrained volume, mass, and cost requirements, with issues of electromagnetic compatibility and increased complexity.

Innovation Solution

The method employs the angular directivity of the radar antenna to detect and isolate other radar transmissions by slaving the radar's waveform to the detected transmission, using distance and frequency resolution, and constructing a matched filter to optimize ESM functionality without increasing equipment volume, mass, or cost, allowing simultaneous radar and ESM operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If distinct radar and ESM equipment are integrated on the carrier, then radar function and ESM function are achieved, but volume, mass, and cost increase

Engineering Contradiction:

Improveradar function and ESM functionVSAvoidvolume

Core Design Contradiction:

Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent combines radar and ESM functions into a single integrated system that shares common hardware resources including antenna, receiver, and signal processing units. The system alternates between active radar mode and passive ESM mode, allowing one equipment to perform multiple functions and thereby reducing overall volume, mass, and cost.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The radar equipment is designed to perform dual functions: active radar surveillance and passive ESM reception. The same antenna and receiver chain are used for both radar transmission/reception and for capturing emissions from other radar systems, making the equipment universal and eliminating the need for separate dedicated ESM hardware.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If distinct radar and ESM equipment are integrated on the carrier, then radar function and ESM function are achieved, but mass increases

Engineering Contradiction:

Improveradar function and ESM functionVSAvoidmass

Core Design Contradiction:

Adaptability or versatilityVSWeight of stationary object

Solution Approach 1:

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If distinct radar and ESM equipment are integrated on the carrier, then radar function and ESM function are achieved, but cost increases

Engineering Contradiction:

Improveradar function and ESM functionVSAvoidcost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

Inventive Principle:

Principle #6Universality (Multi-functionality)

4Adaptability or versatility

If distinct radar and ESM equipment are integrated on the carrier, then radar function and ESM function are achieved, but electromagnetic compatibility problems occur

Engineering Contradiction:

Improveradar function and ESM functionVSAvoidelectromagnetic compatibility

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The system operates in periodic time-sharing mode, alternating between active radar transmission/reception phases and passive ESM reception phases. During ESM phases, the radar transmitter is turned off to avoid electromagnetic interference with the sensitive ESM receiver, allowing both functions to coexist without compatibility issues.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

Before switching to ESM reception mode, the system preliminary stops radar transmission and prepares the receiver for passive reception. This preliminary action ensures that no electromagnetic interference from radar transmission contaminates the ESM signal capture, maintaining electromagnetic compatibility.

Inventive Principle:

Principle #10Preliminary action

5Adaptability or versatility

If ESM coverage is ensured by very wideband antennas with low gain, then ESM function is achieved, but radar function performance decreases

Engineering Contradiction:

ImproveESM functionVSAvoidradar function performance

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS9476971B2Method of radar surveillance and of radar signal acquisition

Publication Date: 2016.10.25 THALES SA

AI summary

A radar includes an antennal structure, with means for transmitting an impulse signal in a band centered on F1 according to a repetition period centered on a recurrence period Tr1 and pulse width T1, with means for receiving signals by the antenna in frequency band ΔF, with a unit for processing the signals received on a set of N distance bins. The signals received are transmitted by another radar in a frequency band centered on F2 where F2−F1≦ΔF, according to a repetition period centered on a period Tr2 and pulse width T2. The signals transmitted by the two radars are asynchronous. The method comprises: slaving frequency F1 to frequency F2, by measuring the power received integrated over the N distance bins and over several recurrences, determination of period Tr2 and T2 and slaving the period centered on Tr1 to a period centered on Tr2 with Tr1=k*Tr2.