Universal Microwave Waveguide Joint for Mass-Balanced Antenna Steering

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing mechanically steerable microwave transmitter systems face challenges in coupling microwave energy efficiently from a stationary source to a rotating antenna while minimizing beam loss, often requiring heavy and bulky gimbal mechanisms and counterweights to maintain mass balance.

Innovation Solution

A universal microwave waveguide joint enabling simultaneous 3-axis rotation and 3-dimensional translation between the antenna and the stationary source, utilizing a circular waveguide slip-joint for translation and ball-joints for rotation, allowing the antenna to be mass-balanced without additional counterweights, and using mode converters to maintain low RF loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the source is affixed to the antenna and supported by the gimbal mechanism, then the beam coupling is direct, but the weight and bulk of the source increases the size and weight of the gimbal mechanism

Engineering Contradiction:

Improvebeam coupling efficiencyVSAvoidgimbal mechanism weight

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The source is extracted from the moving antenna assembly and kept stationary, connected only by a waveguide. This separates the heavy source from the gimbal mechanism, eliminating the need for the gimbal to support and move the source, thereby reducing the weight and bulk of the moving components while maintaining direct beam coupling through the waveguide connection.

Inventive Principle:

Principle #2Taking out (Extraction)

2Ease of operation

If rotary joints are mounted on the gimbal mechanism to allow antenna rotation, then the antenna can rotate with respect to the stationary source, but the center of mass shifts away from the rotation axes requiring heavy counterweights

Engineering Contradiction:

Improveantenna rotation capabilityVSAvoidcounterweight mass

Core Design Contradiction:

Ease of operationVSWeight of moving object

Solution Approach 1:

A universal joint is introduced as an intermediary component in the waveguide path. This universal joint provides the necessary rotational flexibility to accommodate antenna movement while maintaining a compact configuration that allows the center of mass to remain near the rotation axes, minimizing or eliminating the need for heavy counterweights.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Weight of stationary object

If the source is kept stationary with a waveguide extending to the antenna, then the gimbal mechanism size is reduced, but beam loss between source and antenna increases

Engineering Contradiction:

Improvegimbal mechanism sizeVSAvoidbeam loss

Core Design Contradiction:

Weight of stationary objectVSLoss of energy

Solution Approach 1:

The universal joint serves multiple functions simultaneously: it maintains waveguide alignment, accommodates antenna rotation and positioning, and minimizes beam loss through its specialized design. This multi-functional component enables the stationary source configuration to achieve both reduced gimbal size and low beam loss by optimizing the waveguide connection geometry and movement characteristics.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 simplifies the antenna steering mechanism, reduces the size and power requirements of the rotation drive systems, and minimizes beam loss by allowing the antenna to be mass-balanced without additional counterweights, while maintaining efficient power transmission.

Implementation Method 1

The universal joint comprises a circular waveguide slip-joint allowing for 1-dimensional translation along the waveguide axis

Methodology Applied

Scientific EffectSlip-joint mechanism:

Implementation Method 2

first and second circular waveguide ball-joints each allowing for 3-axis rotation around and orthogonal to the waveguide axis

Methodology Applied

Scientific EffectBall-joint mechanism:

Implementation Method 3

a first microwave waveguide mode converter coupled to the beam source that converts the first waveguide mode of the beam to a circular axial symmetric waveguide mode

Methodology Applied

Scientific EffectWaveguide mode conversion: Waveguide

Data Source

PatentUS8963790B2Universal microwave waveguide joint and mechanically steerable microwave transmitter

Publication Date: 2015.02.24 RAYTHEON CO

AI summary

A universal joint comprising a pair of circular waveguide ball-joints and a slip-joint allows for simultaneous 3-axis rotation and 3-dimensional translation between an antenna and a stationary source. As such, the universal joint does not have to be physically aligned with the azimuth, and elevation, rotation axis of the antenna and mounted on the gimbal support, greatly simplifying the antenna steering mechanism. The universal joint allows the antenna to be mass-balanced in relation to the azimuth and elevation axis without adding any additional counter weights, thus reducing the size and power requirements of the azimuth and elevation rotation drive systems. Additional ball-joints may be provided to increase the allowed range of motion of the antenna.