Dome RF Window for Adjustable Coupling Loop in Electron Beam Tubes

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing linear beam tube devices, particularly those with integral output cavities, face challenges in adjusting the orientation of the output coupling loop after the vacuum seal is established, limiting flexibility and efficiency in RF signal amplification.

Innovation Solution

An RF window arrangement using a ceramic dome or similar structure that protrudes into the interaction cavity, allowing the output coupler to extend into the cavity while remaining outside the vacuum envelope, providing an airtight seal and RF transparency, enabling adjustment of the coupling loop without compromising the vacuum.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the output coupling loop is placed inside the vacuum envelope (integral cavity arrangement), then the coupling efficiency is improved, but the adjustability of the loop orientation after vacuum sealing is lost

Engineering Contradiction:

Improvecoupling efficiencyVSAvoidadjustability of coupling loop orientation

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The invention divides the output coupling structure into two separate parts: the coupling loop remains inside the vacuum envelope for optimal coupling efficiency, while the adjustable mechanism and control elements are placed outside the vacuum envelope. This segmentation allows the loop to be positioned for maximum efficiency while enabling external adjustment of its orientation and coupling characteristics.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention introduces an intermediary structure (such as a flexible cable or adjustable connector) that connects the coupling loop inside the vacuum envelope to the external adjustment mechanism. This intermediary allows the loop to maintain its optimal position for coupling while permitting external control and adjustment of its orientation and coupling strength.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the output coupling loop is placed outside the vacuum envelope (external cavity arrangement), then the adjustability is improved, but the coupling efficiency deteriorates

Engineering Contradiction:

Improveadjustability of coupling loopVSAvoidcoupling efficiency

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The coupling system is segmented into an internal loop component that maintains close proximity to the interaction cavity for efficient coupling, and an external adjustment mechanism that provides adaptability. The internal loop is positioned to maximize magnetic coupling with the cavity while the external mechanism allows adjustment of coupling strength and orientation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention extends the coupling structure into a third dimension by using a loop that penetrates through the vacuum envelope, allowing the majority of the loop to remain inside the envelope for efficient coupling while the adjustment mechanism extends outside. This dimensional arrangement optimizes both coupling efficiency and adjustability simultaneously.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Reliability

If a rigid vacuum seal is used to maintain vacuum integrity, then the vacuum stability is improved, but the flexibility to adjust internal components is lost

Engineering Contradiction:

Improvevacuum stabilityVSAvoidflexibility to adjust components

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The vacuum envelope is segmented to create a sealed chamber that maintains vacuum integrity while incorporating an opening or penetration point for the coupling loop. The seal is maintained around the loop structure, allowing the vacuum to be stable while the loop can be adjusted externally without compromising vacuum stability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention employs flexible sealing mechanisms (such as flexible membranes or adjustable seals) that maintain vacuum integrity while allowing for adjustment of the coupling loop orientation and position. These flexible seals accommodate the movement and adjustment of the loop while preventing vacuum leakage.

Inventive Principle:

Principle #30Flexible shells and thin films

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 allows for flexible adjustment and positioning of the output coupling loop, enhancing the efficiency and adaptability of linear beam tube devices by maintaining the vacuum integrity and RF transparency, thus improving the overall performance of electron beam tube devices.

Implementation Method 1

provides an airtight seal to the vacuum within the tube

Methodology Applied

Scientific EffectVacuum seal:

Implementation Method 2

substantially transparent to RF

Methodology Applied

Scientific EffectRF transparency:

Data Source

PatentUS7417376B2Linear electron beam tube having a dome shape RF window

Publication Date: 2008.08.26 TELEDYNE UK LTD

AI summary

An electron beam tube device such as an inductive output tube of the integral cavity type has a RF window which re-enters the interaction space within the cavity thereby defining a space that is within the interaction cavity but is outside the vacuum. An output coupler in the form of an output coupling loop protrudes into this space and thus couples with the electromagnetic field within the interaction space, whilst remaining outside the vacuum envelope. This allows the coupling loop to be adjusted without any additional seal arrangement between the coupling loop and walls of the output cavity.