Radar Receiver Distortion Suppression Using Correction Signals

Solution Overview

Problem

Modern multichannel wideband radar systems experience sensitivity reduction due to distortion from transmission means, especially in proximity to receiving means, which automatic gain control fails to adequately address.

Innovation Solution

A method involving a radar system with a transmitting antenna, receiving antenna, and control unit to identify and generate a correction signal in the frequency span of the received signal, feeding it into the channel to dampen interfering signals, thereby reducing external disturbances and avoiding the limitations of automatic gain control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If automatic gain control is used to reduce distortion from transmission means, then interference from transmission signals is reduced, but sensitivity of the radar system is reduced

Engineering Contradiction:

Improvedistortion from transmission meansVSAvoidsensitivity of radar system

Core Design Contradiction:

Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The patent converts the harmful high-power transmission signal into a beneficial reference signal for generating correction signals. By using the transmission signal itself to create anti-phase correction signals, the system transforms the source of distortion into the means for eliminating distortion, thereby reducing interference while preserving sensitivity without the trade-off imposed by automatic gain control.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The system applies preliminary anti-action by generating correction signals in advance that are designed to cancel out the expected distortion from transmission means. These correction signals are injected into the receiving channels before the distortion fully manifests, proactively neutralizing the harmful effects while maintaining the system's ability to detect weak reflected signals.

Inventive Principle:

Principle #9Preliminary anti-action

2Measurement precision

If the receiving means detects significantly lower powers to detect small targets far away, then detection capability for distant targets is improved, but the receiving means becomes more susceptible to distortion from transmission means

Engineering Contradiction:

Improvedetection capability for distant targetsVSAvoiddistortion from transmission means

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful high-power transmission signal into a beneficial reference signal for generating correction signals. By using the transmission signal itself to create anti-phase correction signals, the system transforms the source of distortion into the means for eliminating distortion, thereby reducing interference while preserving sensitivity without the trade-off imposed by automatic gain control.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The correction signal acts as an intermediary that mediates between the high-power transmission signal and the low-power reflected signals. By injecting this intermediate correction signal into the receiving channels, the system neutralizes the harmful effects of the transmission signal on the sensitive receiving means, enabling detection of distant targets without being overwhelmed by transmission-induced distortion.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Power

If automatic gain control increases gain to detect stronger echoes, then detection of strong signals is improved, but sensitivity for weak signals is reduced

Engineering Contradiction:

Improvegain of receiving meansVSAvoidsensitivity for weak signals

Core Design Contradiction:

PowerVSMeasurement precision

Solution Approach 1:

The patent converts the harmful high-power transmission signal into a beneficial reference signal for generating correction signals. By using the transmission signal itself to create anti-phase correction signals, the system transforms the source of distortion into the means for eliminating distortion, thereby reducing interference while preserving sensitivity without the trade-off imposed by automatic gain control.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The system applies dynamic correction by continuously generating and adjusting correction signals based on the transmitted signal characteristics. This dynamic approach allows the receiving means to maintain optimal sensitivity across varying signal conditions without the coarse gain adjustments of automatic gain control, preserving the ability to detect both strong and weak signals simultaneously.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS12487321B2Active receiver distortion suppression in a radar system

Publication Date: 2025.12.02 SAAB AB

AI summary

A method for operating a radar in a radar system to cancel an external disturbance in a received signal is provided. The method comprises receiving a signal at the receiving antenna, receiving the signal at the control unit, identifying interfering signal, generating a correction signal and feeding the correction signal. The correction signal is arranged to dampen the interfering signal in the frequency span in the received signal. Thereby the external disturbance is reduced.