Smartphone GNSS Antenna Switching Between Linear and Circular Polarization
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Solution Overview
Problem
Conventional GNSS antennas in smartphones suffer from polarization mismatch losses and are susceptible to multipath signals due to their linear polarization design, which affects positioning accuracy.
Innovation Solution
A GNSS receiver with a hybrid coupler combining two linear polarization antennas to generate a circularly polarized signal, utilizing a 90° hybrid coupler to enhance signal power and reject multipath signals, allowing dynamic configuration between linear and circular polarization modes based on environmental conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a linear polarization antenna is used for GNSS reception, then the device complexity is reduced, but polarization mismatch losses occur and positioning accuracy deteriorates
Solution Approach 1:
The patent combines two linear polarization antennas with orthogonal orientations (one for vertical polarization, one for horizontal polarization) to receive GNSS signals. By merging the outputs of these two antennas through a hybrid coupler, the system achieves circular polarization capability while using simple linear polarization antenna elements, thus resolving the contradiction between device complexity and positioning accuracy.
Solution Approach 2:
The patent creates a composite polarization reception system by combining signals from two different linear polarization antennas (with orthogonal orientations) to form a circular polarization reception capability. This composite approach allows the system to achieve the benefits of circular polarization (reduced polarization mismatch loss and improved positioning accuracy) while maintaining the simplicity of linear polarization antenna structures.
2Device complexity
If a linear polarization antenna is used, then the antenna design is simplified, but susceptibility to multipath signals increases
Solution Approach 1:
The patent merges signals from two linear polarization antennas with orthogonal orientations through a hybrid coupler to create a circular polarization reception system. This combination provides multipath rejection capability because circular polarization can distinguish between direct line-of-sight signals and reflected multipath signals, thereby reducing susceptibility to harmful multipath effects while maintaining simple linear polarization antenna designs.
3Measurement precision
If circular polarization is implemented using separate antennas, then positioning accuracy improves, but device complexity increases
Solution Approach 1:
The patent implements circular polarization by merging the outputs of two existing linear polarization antennas through a hybrid coupler, rather than using separate dedicated circular polarization antennas. This approach achieves the positioning accuracy benefits of circular polarization while utilizing the antenna structures already present in the device, thus minimizing the increase in device complexity.
Solution Approach 2:
The patent makes the linear polarization antennas serve multiple functions: they can individually receive linearly polarized signals, and when combined through the hybrid coupler, they collectively provide circular polarization reception capability. This multi-functionality allows the system to achieve circular polarization benefits without adding dedicated circular polarization antenna structures, thereby limiting the increase in device complexity.
4Measurement precision
If signal power is enhanced through combining, then positioning accuracy improves, but additional hardware components are required
Solution Approach 1:
The patent combines signals from two linear polarization antennas through a hybrid coupler to enhance the received signal power and achieve circular polarization. The hybrid coupler is a passive component that performs the combining function without requiring additional active electronics, thus providing signal power enhancement while keeping the additional hardware requirements minimal.
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
Improves positioning accuracy by reducing signal loss and rejecting multipath signals, providing better performance in various environmental conditions with minimal additional hardware.
Implementation Method 1
a first linear polarization antenna configured to receive a first linear polarization component of a GNSS signal... a second linear polarization antenna configurable to receive a second linear polarization component of the GNSS signal... a hybrid coupler... outputting a combined GNSS signal
Data Source
AI summary
A Global Navigation Satellite System (GNSS) receiver for a portable device includes a first linear polarization antenna configured to receive a first linear polarization component of a GNSS signal; a second linear polarization antenna configurable to receive a second linear polarization component of the GNSS signal, a radio frequency signal conforming to a second wireless communication technology, or both; and a hybrid coupler that combines the first linear polarization component of the GNSS signal and the second linear polarization component of the GNSS signal to generate a circularly polarized GNSS signal. In some embodiments, the GNSS receiver includes a tuner to tune the resonant frequency of the second linear polarization antenna. In some embodiments, the GNSS receiver includes a switch or a filter to connect or disconnect the second linear polarization antenna from the hybrid coupler to implement a circular polarization antenna or a linear polarization ante.