Laser Transmit Module Layout for Low-Inductance LiDAR Pulses

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Solution Overview

Problem

Current laser radars are limited by transmit power, resulting in a restricted detection distance that cannot be further increased, which is a critical issue for advanced vehicle autonomous driving applications.

Innovation Solution

A laser transmit module is designed with a capacitor, laser transmitter, and field effect transistor interconnected through conductive pins to form a laser transmission loop, minimizing loop inductance by reducing the area of the loop and enhancing pulse peak value.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the laser transmission loop area is reduced to minimize loop inductance, then the pulse peak value and detection distance are improved, but the component layout complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvedetection distanceVSAvoidcomponent layout complexity
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent transitions from a planar two-dimensional layout to a three-dimensional stacked configuration. The capacitor, laser transmitter, and field effect transistor are arranged vertically in layers rather than horizontally on a plane, allowing the formation of a compact laser transmission loop with minimized area while maintaining proper electrical connections through vertical conductive pathways.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent implements a nested hierarchical structure where components are organized into layered packages. The capacitor, laser transmitter, and field effect transistor are nested within a compact footprint, with each component positioned in a specific layer and connected through vertical conductive pins that penetrate through the stack, creating a space-efficient three-dimensional integration.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Measurement precision

If the detection distance is increased by improving pulse peak value, then the laser transmit power must be increased, but this increases the total power consumption and system complexity

Engineering Contradiction:
Improvedetection distanceVSAvoidtotal power consumption
Core Design Contradiction:
Measurement precisionVSPower

Solution Approach 1:

The patent changes the electrical parameters of the laser transmission loop by minimizing loop inductance through optimized component placement and compact loop geometry. This parameter optimization allows the system to achieve higher pulse peak values for the same capacitor discharge, effectively increasing detection distance without increasing the capacitor size or total power consumption.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent converts the potentially harmful effect of loop inductance, which normally causes pulse broadening and peak value reduction, into a benefit by minimizing it to nearly zero. This transformation allows the system to achieve sharp, high-peak laser pulses with narrow width, improving detection distance and precision while maintaining controlled power consumption.

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

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

The solution increases the detection distance and precision of the laser radar by reducing loop inductance, allowing for higher peak power and narrower pulse width without increasing total power, thus improving autonomous driving capabilities.

Implementation Method 1

a capacitor, configured to supply power to the laser transmitter

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

a laser transmitter...transmitted a detection laser

Methodology Applied
Scientific EffectLaser emission: Laser

Implementation Method 3

The capacitor, the laser transmitter, and the field effect transistor are interconnected through conductive pins to form a laser transmission loop

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 4

loop inductance generated by the laser transmission loop affects a pulse peak value of a laser pulse

Methodology Applied
Scientific EffectLoop inductance: Inductor

Data Source

PatentEP4253997B1Laser transmission module, laser radar, and mobile platform
Publication Date: 2026.01.28 HUAWEI TECH CO LTD
  • EP4253997B1 patent drawingFigure 1~2
  • EP4253997B1 patent drawingFigure 3
  • EP4253997B1 patent drawingFigure 4

AI summary

This application provides a laser transmit module, a laser radar, and a mobile platform. The laser transmit module includes a capacitor, a laser transmitter, and a field effect transistor. The capacitor is configured to supply power to the laser transmitter. The field effect transistor is configured to control the laser transmitter to be turned on. The capacitor, the laser transmitter, and the field effect transistor are interconnected through conductive pins to form a laser transmission loop. The capacitor, the laser transmitter, and the field effect transistor are fixedly connected through the interconnected conductive pins. A loop inductance generated by the laser transmission loop affects a pulse peak value of a laser pulse transmitted by the laser transmitter, thereby affecting a detection distance of the laser pulse. Therefore, the laser transmission loop is formed through a direct connection between the conductive pins of the capacitor, the laser transmitter, and the field effect transistor, to reduce distances between the components and reduce an area of the formed laser transmission loop, so as to reduce the loop inductance, increase the pulse peak value of the laser pulse, and further increase the detection distance of the laser pulse transmitted by the laser transmit module.