Microwave Package Base Plate Waveguide Cavity Design

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Solution Overview

Problem

Existing microwave communication packages face mismatch losses due to waveguides constructed through solid dielectric substrates, requiring propagation through dissimilar physical sizes of substrate and base plate waveguides, and lack hermetic sealing and efficient cooling for circuit components.

Innovation Solution

A microwave communication package design featuring a cavity in an electrically conducting base plate with the dielectric substrate covering it, mounting circuitry within the cavity, and using waveguides through the base plate to connect microstrip lines and antennas, eliminating substrate waveguides and enabling hermetic sealing and enhanced cooling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If waveguides are constructed through the substrate material, then a conduit for microwave communication is provided, but mismatch losses occur due to dissimilar physical sizes of substrate and base plate waveguides

Engineering Contradiction:
Improvemicrowave communication reliabilityVSAvoidmismatch loss
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The invention extracts the waveguide function from the substrate material and relocates it to the base plate. By removing the substrate waveguide entirely and replacing it with a base plate waveguide that couples directly to microstrip lines, the design eliminates the mismatch loss problem caused by dissimilar waveguide dimensions while maintaining microwave communication functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces microstrip lines as an intermediary element between the base plate waveguide and the antenna circuitry. This mediator allows for efficient energy transfer without requiring a substrate waveguide, thereby eliminating mismatch losses while providing the necessary conduit for microwave communication.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If the substrate and antenna are mounted on opposite sides of a base plate, then a complete package structure is achieved, but hermetic sealing is difficult to implement

Engineering Contradiction:
Improvepackage structure stabilityVSAvoidprotection from moisture
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The invention changes the spatial arrangement by mounting both the substrate and antenna on the same side of the base plate, utilizing the vertical dimension within the base plate cavity. This dimensional reconfiguration allows the substrate to cover and seal the cavity, providing hermetic protection while maintaining structural stability.

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

Solution Approach 2:

The substrate is positioned to cover the base plate cavity, creating a nested structure where the substrate acts as a cover for the cavity. This nesting arrangement enables hermetic sealing by enclosing the circuitry within the cavity while maintaining package integrity.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Reliability

If waveguides are constructed through the substrate, then microwave communication is enabled, but the circuitry cannot be easily cooled

Engineering Contradiction:
Improvemicrowave communication functionalityVSAvoidcircuit component temperature
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The invention extracts the circuitry from the substrate and relocates it to the base plate cavity. This extraction allows direct thermal contact with the base plate, enabling efficient heat removal through the base plate while maintaining microwave communication functionality through the base plate waveguide.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The base plate serves as a thermal intermediary, providing a direct thermal path from the circuitry in the cavity to the external environment. This mediator enables efficient heat transfer without requiring thermal vias through the substrate, thereby improving cooling capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 design eliminates mismatch losses, provides hermetic protection, facilitates easy overmolding, and allows for effective cooling of circuit components by placing them within the cavity, improving the package's performance and reliability.

Implementation Method 1

One or more waveguides extend through the base plate, and each waveguide has a first coupling directly to one of the microstrip lines and a second coupling to the antenna apparatus

Methodology Applied
Scientific EffectWaveguide: Waveguide

Implementation Method 2

A dielectric substrate is mounted on the first side of the base plate covering the base plate cavity, with sealing apparatus contacting the dielectric substrate and the base plate completely around the base plate cavity, whereby the base plate cavity is substantially hermetically sealed

Methodology Applied
Scientific EffectHermetic sealing:

Implementation Method 3

allows for effective cooling of circuit components by placing them within the cavity, improving the package's performance and reliability

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2043150B1Microwave Communication Package with electronic circuits and antenna
Publication Date: 2016.07.20 DELPHI TECHNOLOGIES INC
  • EP2043150B1 patent drawingFigure 1
  • EP2043150B1 patent drawingFigure 2
  • EP2043150B1 patent drawingFigure 3~4

AI summary

A microwave communication package (10) is constructed on an electrically conducting base plate (12) having a first side (14) defining a base plate cavity (16), with an antenna apparatus (40) mounted on an opposite, second side (18). A dielectric substrate (20) on the first side of the base plate covers the base plate cavity; and sealing apparatus (72) contacting the dielectric substrate and the base plate completely around the base plate cavity hermetically seals the cavity. Circuitry (30, 32) mounted on a surface of the substrate within the base plate cavity includes one or more microstrip lines (54) communicating components (30) to one or more waveguides comprising openings (50) extending through the base plate; and the waveguides are coupled at their opposite ends to the antenna apparatus.