Dual-Function Secondary Radar Subsystem Segmentation

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Solution Overview

Problem

Current dual-function secondary radars face challenges in simultaneously achieving optimal performance for both surveillance and friend/foe recognition functions, often resulting in degraded functionalities, reduced service, and compromised rotational speed or instrumented distance due to structural and processing compromises.

Innovation Solution

A secondary radar system with two sub-assemblies, one for SSR and one for IFF, operating independently and simultaneously, with shared mechanical, energy, and civil engineering resources, allowing for separate and asynchronous signal processing and transmission, and utilizing common rotary joint and radiating elements to maintain performance and independence of functions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single radar integrates both SSR and IFF functions in a single subsystem, then device complexity is reduced, but functionality is degraded during alternating operation and performance is reduced when operating simultaneously

Engineering Contradiction:
Improveradar infrastructureVSAvoidfunctional performance
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent divides the secondary radar into two independent sub-assemblies: an SSR sub-assembly and an IFF sub-assembly. Each sub-assembly has its own dedicated antenna, transmitting/receiving means, and processing means. This segmentation allows both functions to operate simultaneously and independently without mutual interference, resolving the contradiction between device simplicity and functional performance.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If two separate co-located radars are used for SSR and IFF functions, then functional performance is maintained, but device complexity increases and reciprocal masks occur

Engineering Contradiction:
Improvefunctional performanceVSAvoidradar infrastructure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the SSR and IFF radars into a single integrated device with shared mechanical resources (common rotary joint, common support structure). The two sub-assemblies are coupled to the same rotary joint, allowing them to rotate together as a unified structure. This merging reduces device complexity and eliminates reciprocal masks while maintaining the independence and performance of both functions through separate signal processing paths.

Inventive Principle:
Principle #5Merging (Combining)

3Adaptability or versatility

If a single radar performs both SSR and IFF functions simultaneously, then versatility is improved, but illumination time is insufficient for high-speed rotating radars

Engineering Contradiction:
Improvedual-function capabilityVSAvoidtarget illumination time
Core Design Contradiction:
Adaptability or versatilityVSDuration of action of moving object

Solution Approach 1:

By segmenting the radar into two independent sub-assemblies with separate antennas and processing chains, the patent allows each function to operate independently. The SSR sub-assembly can illuminate targets continuously for surveillance while the IFF sub-assembly performs identification functions, effectively doubling the available illumination time compared to alternating operation modes.

Inventive Principle:
Principle #1Segmentation

4Device complexity

If SSR and IFF functions share a single antenna system, then device complexity is reduced, but mutual interference occurs between the two functions

Engineering Contradiction:
Improveantenna systemVSAvoidreciprocal masks and interference
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent assigns dedicated antennas to each sub-assembly: a first antenna for SSR and a second antenna for IFF. This physical segmentation of the antenna system eliminates mutual interference and reciprocal masks between the two functions, as each antenna operates independently in its own spatial and temporal domain.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2922144B1Dual-function secondary radar, and radar system comprising such a radar
Publication Date: 2016.06.15 THALES SA
  • EP2922144B1 patent drawingFigure 1
  • EP2922144B1 patent drawingFigure 2~3
  • EP2922144B1 patent drawingFigure 4~5

AI summary

The secondary SSR and IFF radar comprises a first sub-assembly (60) performing a surveillance function and a second sub-assembly (70) performing an identification function. The two sub-assemblies operate simultaneously and independently of each other. The first sub-assembly is coupled to a first antenna (51, 53) capable of rotation via a rotary joint (61), and the second sub-assembly is coupled to a second antenna (52, 54) via the same rotary joint. The two antennas are mounted back-to-back. The radar system comprises a primary surveillance radar (PSR) and a secondary radar as defined above. The radar system can advantageously be predominantly civilian in a PSR + SSR and IFF configuration or predominantly military in a PSR + IFF and SSR configuration.