Planar Optoelectronic Device for High-Power Microwave Signal Generation

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Solution Overview

Problem

Current optoelectronic devices face challenges in generating high-frequency, high-power RF signals due to limitations in photodiode power resistance, which is exacerbated by parasitic capacitance with large dimensions and inefficient power distribution in existing solutions, leading to low yield and large antenna sizes.

Innovation Solution

An optoelectronic device that divides an input optical beam into elementary beams and uses a series connection of semiconductor photodiodes with a planar metal assembly to form a compact antenna, ensuring relative optical delay is less than the signal period, allowing for coherent superposition and efficient power multiplication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the geometric dimensions and layer thicknesses of photodiodes are increased to increase power resistance, then the power resistance is improved, but the frequency response deteriorates due to increased parasitic capacitance

Engineering Contradiction:
Improvepower resistanceVSAvoidfrequency response
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The patent divides a single large photodiode into multiple smaller photodiodes arranged in series. Each small photodiode has reduced dimensions and thickness, maintaining good frequency response with low parasitic capacitance. The series connection of multiple photodiodes achieves high power resistance equivalent to a large photodiode, while preserving high-frequency performance.

Inventive Principle:
Principle #1Segmentation

2Power

If large dimensions are used for photodiodes to generate high power, then the power generation capability is improved, but the parasitic capacitance increases leading to poor high-frequency performance

Engineering Contradiction:
Improvepower generation capabilityVSAvoidparasitic capacitance
Core Design Contradiction:
PowerVSObject-affected harmful factors

Solution Approach 1:

The patent segments a large photodiode structure into multiple smaller photodiodes connected in series. This segmentation reduces the area and dimensions of each individual photodiode, thereby reducing parasitic capacitance while maintaining the overall power handling capability through the series configuration. The total power generation capability is preserved as the series connection allows handling of high incident optical power distributed across multiple elements.

Inventive Principle:
Principle #1Segmentation

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

This solution enables the generation and radiation of high-frequency, high-power RF signals with improved efficiency and compactness, overcoming the limitations of existing technologies by ensuring coherent wave emission and reduced antenna size.

Implementation Method 1

a set of n photodiodes comprising a semiconductor material arranged on at least one line, the photodiodes of a line being electrically connected together in series

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 2

the metal assembly and the assembly of photodiodes forming an antenna capable of radiating said electromagnetic signal

Methodology Applied
Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Data Source

PatentEP4010932B1Planar optoelectronic device for generating a microwave signal
Publication Date: 2023.08.09 THALES SA
  • EP4010932B1 patent drawingFigure 1
  • EP4010932B1 patent drawingFigure 2
  • EP4010932B1 patent drawingFigure 3

AI summary

The invention relates to an optoelectronic device (10) for generating and radiating an electromagnetic signal (S), comprising: - a dividing guide (SW) configured to divide an input optical beam (OB) that is a carrier of said electromagnetic signal (S) into n elementary beams (OBi), - a set of n photodiodes (PDi) that comprise a semiconductor material, said photodiodes being arranged in at least one row, the photodiodes of a row being electrically connected to one another in series by a planar metal assembly (ME) comprising a plurality of metal elements (Mele), - the dividing guide (SW) furthermore being configured to inject an elementary beam into an associated photodiode (PDi), - the metal assembly (ME) and the set of photodiodes forming an antenna (Ant) that is able to radiate said electromagnetic signal (S), each photodiode forming one electrical input of the antenna, the antenna having a length (L0) equal to a multiple of half a central wavelength (λ0) computed from the central frequency.