Pulse Radar Device Using Complementary Sub-Pulse Sequences for RF Error Cancellation

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Solution Overview

Problem

Conventional pulse radar devices using π/2-BPSK modulation require additional circuits and procedures for IQ error correction, leading to increased costs and complexity due to the need for calculating correction parameters during a training period.

Innovation Solution

A pulse radar device that generates transmission signals using complementary sub-pulse sequences with specific correlation constraints and phase rotation methods to reduce RF errors without the need for additional correction circuits, thereby canceling IQ and DC errors within the device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an IQ error correction circuit is added to reduce RF errors, then the reliability of the radar device is improved, but the device complexity and cost increase

Engineering Contradiction:
ImproveRF error reductionVSAvoidcircuit complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent converts the harmful RF errors (IQ errors and DC offsets) into a beneficial effect by designing complementary sub-pulse sequences where the errors from one sequence cancel out the errors from the other sequence. The correlation calculation automatically eliminates RF errors without requiring additional correction circuits, thus converting the harmful error signals into a self-correcting mechanism.

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

Solution Approach 2:

The radar device performs self-correction of RF errors through the inherent properties of the complementary sub-pulse sequences. The system uses its own transmitted signals to automatically cancel out RF errors during the correlation calculation process, eliminating the need for external correction circuits or separate calibration procedures.

Inventive Principle:
Principle #25Self-service

2Measurement precision

If correction parameters are calculated during a training period, then the measurement precision of RF errors is improved, but the productivity of the radar device decreases

Engineering Contradiction:
ImproveRF error correction accuracyVSAvoidoperational efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent incorporates error cancellation capability directly into the pulse sequence design from the beginning, rather than requiring preliminary training to calculate correction parameters. The complementary sub-pulse sequences are pre-configured to automatically cancel RF errors during normal operation, eliminating the need for separate training periods.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If additional circuits for RF error correction are added, then the reliability is improved, but the power consumption increases

Engineering Contradiction:
ImproveRF error reductionVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent converts the harmful RF errors into a self-canceling mechanism through mathematical design of the pulse sequences. The correlation calculation between complementary sequences automatically eliminates RF errors, converting what would require power-intensive correction circuits into a computationally efficient error cancellation process.

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

Data Source

PatentEP2947475B8Pulse radar device and control method therefor
Publication Date: 2018.06.27 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

AI summary

A transmission system is provided with a pulse sequence generator (210) that generates a pulse sequence including Golay code or Spano code, a π/2-BPSK modulator (220) that applies π/2-BPSK modulation to the pulse sequence generated by the pulse sequence generator, and a phase rotator (410) that provides phase rotation for every pulse for output of the π/2-BPSK modulator and a reception system is provided with a phase rotator (420) that provides a phase opposite to a phase provided by the phase rotator of the transmission system and a correlator (340,342) that performs correlation calculation for output of the phase rotator, based on the output of the π/2-BPSK modulator (220).