Multi-band Inverted-L Antenna Impedance Matching
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Solution Overview
Problem
Existing multi-band antennas for global satellite positioning systems are complex and costly, requiring multiple antennas for different frequency bands, which can degrade the accuracy of range measurements and position fixes due to physical displacement.
Innovation Solution
A multi-band antenna design featuring a pair of inverted-L elements with delay lines and resonance circuits that maintain constant impedance across different frequency bands, allowing signals to be transmitted and received in multiple bands using fewer antennas, including the L1, L2, L5, and L-band communications frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple antennas are used for different frequency bands, then signal reception capability across multiple bands is improved, but device complexity and cost increase
Solution Approach 1:
The patent implements a single antenna structure that can operate across multiple frequency bands (L1, L2, L5, and L-band communications) by using frequency-dependent impedance transformation networks. The antenna elements and associated circuits are designed to present appropriate impedance characteristics at each operating frequency, enabling one antenna to replace multiple band-specific antennas, thereby reducing system complexity while maintaining multi-band reception capability
2Adaptability or versatility
If multiple antennas are physically displaced for different frequency bands, then frequency-specific reception is improved, but measurement precision of range measurements deteriorates
Solution Approach 1:
The patent combines multiple antenna elements into a single integrated antenna structure with common feed points and shared impedance transformation networks. This merging ensures that all antenna elements are co-located at the same physical position, eliminating baseline errors that would arise from physical displacement of separate antennas, while still providing frequency-specific reception through impedance control
3Adaptability or versatility
If multiple antennas and front-end electronics are used, then signal reception coverage is improved, but expense of receivers increases
Solution Approach 1:
The patent designs a universal antenna structure with frequency-selective impedance transformation that can handle multiple frequency bands through a single antenna interface. This eliminates the need for multiple separate antenna systems and their associated front-end electronics, directly reducing component count, system complexity, and overall receiver expense while maintaining comprehensive signal reception coverage across L1, L2, L5, and L-band communications frequencies
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
The design enables accurate and efficient reception of signals across multiple frequency bands with reduced complexity and cost, improving the accuracy of position fixes in GNSS receivers by maintaining consistent impedance and radiation patterns across the frequency range.
Implementation Method 1
A first delay line in the first pair of delay lines and the second pair of delay lines is configured to phase shift electrical signals coupled to the first antenna element and the second antenna element such that a first impedance of the antenna is approximately equal in the first band of frequencies and the second band of frequencies
Implementation Method 2
The first resonance circuit and the second resonance circuit are configured to each have an impedance greater than a predetermined value in the second band of frequencies such that electrical signals corresponding to the first band of frequencies are coupled to and from the first antenna element and the second antenna element and electrical signals corresponding to the second band of frequencies are substantially coupled to and from a portion of the first antenna element and a portion of the second antenna element
Data Source
AI summary
An antenna includes a first antenna element and a second antenna element. The first antenna element and the second antenna element are configured to transmit and receive signals in a first band of frequencies and in a second band of frequencies. A first pair of delay lines is coupled to the first antenna element and a second pair of delay lines coupled to the second antenna element. A first delay line in the first pair of delay lines and the second pair of delay lines is configured to phase shift electrical signals coupled to the first antenna element and the second antenna element such that a first impedance of the antenna is approximately equal in the first band of frequencies and the second band of frequencies. A second delay line in the first pair of delay lines and the second pair of delay lines is configured to convert the first impedance to a second impedance.