GNSS Antenna with Selectable Gain Pattern and Adjustable Height

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Solution Overview

Problem

Current GNSS antennas fail to provide adaptable gain patterns for varying vehicle orientations and are susceptible to multipath interference, especially at low elevation angles, which affects signal reception and accuracy.

Innovation Solution

A crossed-dipole antenna with selectable gain patterns is designed, featuring an adjustable-height radiating arm element assembly and a reconfigurable ground base, allowing for customizable beamwidth and multipath rejection by varying the support height and arm deflection, maintaining constant input impedance for versatile applications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the antenna uses a fixed gain pattern design, then the structure is simple, but it cannot adapt to different vehicle orientations and operating conditions

Engineering Contradiction:

Improveadaptability to different vehicle orientationsVSAvoidantenna structure complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The antenna employs a reconfigurable ground base with switchable ground elements that can dynamically change the gain pattern configuration. This allows the antenna to adapt its radiation characteristics to match different vehicle orientations and operating conditions, transforming a static structure into a dynamic, adaptable system without requiring complete structural redesign

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The antenna design integrates multiple ground elements that can be selectively activated to serve different functions. The same physical structure can provide multiple gain patterns (e.g., broadside, end-fire, omnidirectional) depending on which ground elements are connected, making the antenna universally applicable to various vehicle types and operating scenarios

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If the antenna has strong gain patterns at low elevation angles, then below-horizon signal reception is improved, but multipath interference from ground reflections increases

Engineering Contradiction:

Improvesignal reception reliabilityVSAvoidmultipath interference

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The antenna uses switchable ground elements to change the electrical parameters of the antenna system. By selectively connecting or disconnecting specific ground elements, the gain pattern can be adjusted to either emphasize low elevation angles for below-horizon reception or create nulls at low angles to reject multipath interference, depending on operational requirements

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The reconfigurable ground base allows the antenna to convert the harmful effect of ground reflections into a beneficial feature. When multipath rejection is needed, the same ground structure that causes reflections is reconfigured to create destructive interference patterns for reflected signals while maintaining constructive interference for direct signals

Inventive Principle:

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

3Adaptability or versatility

If the support height is increased to achieve wide beamwidth for pitch and roll compensation, then signal reception in varying attitudes is improved, but the antenna height increases

Engineering Contradiction:

Improvebeamwidth for vehicle motion compensationVSAvoidantenna support height

Core Design Contradiction:

Adaptability or versatilityVSLength of stationary object

Solution Approach 1:

Instead of using a fixed tall structure, the patent employs a reconfigurable ground base that can dynamically adjust its electrical characteristics. This allows the antenna to achieve wide beamwidth characteristics through ground element configuration rather than physical height, providing the necessary adaptability for vehicle motion compensation without the penalty of increased antenna height

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS8102325B2GNSS antenna with selectable gain pattern, method of receiving GNSS signals and antenna manufacturing method

Publication Date: 2012.01.24 HEMISPHERE GNSS

AI summary

An antenna is provided for GNSS and other applications and includes an adjustable-height vertical support PCB mounted on a ground plane and mounting a crossed-dipole radiating arm element assembly. The gain pattern of the antenna can be varied by constructing the vertical support PCB with different heights or adjusting the height and gain pattern in the field. Vehicles with significant pitch and roll can be provided with low-horizon tracking capability by providing a high-profile antenna configuration. Alternatively, low-profile configurations provide steeper gain pattern rolloff at the horizon for maximal multipath rejection and high accuracy. The droop angles of the radiating arm elements are also adjustable for varying the gain pattern and beamwidth. A matching and phasing network is connected to the radiating arm elements and provides a relatively constant input impedance for the various antenna configurations. Alternative aspects of the invention have different configurations of the radiating arm elements and ground planes.