GNSS RF Receiver PLL Sharing for Multi-Band Jammer Avoidance
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Solution Overview
Problem
Conventional GNSS receivers face challenges in efficiently processing multiple frequency bands due to signal interference and increased size, cost, and pin count when using common components for different signal paths, which degrades signal resolution and adds weight to the receiver.
Innovation Solution
A method and RF receiver design that utilizes a shared phase locked loop to generate local oscillator signals for downconversion, with adjustable divider values to optimize frequency settings for each band, minimizing interference and reducing component count.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If common components are used for different signal paths to reduce cost and size, then device complexity and cost are reduced, but signal interference increases and signal resolution degrades
Solution Approach 1:
The patent segments the signal processing into multiple paths (first signal path and second signal path) with different downconversion schemes. The first signal path uses dual downconversion with adjustable divider values to process signals in a first frequency band, while the second signal path uses single downconversion for a second frequency band. This segmentation allows each path to be optimized for its specific frequency band, reducing signal interference while maintaining component sharing where possible.
Solution Approach 2:
The patent employs dynamic adjustment of oscillator divider values in the first signal path to adapt to different frequency bands and jammer frequencies. The controller dynamically selects between different divider values based on the detected jammer frequency, enabling the system to optimize performance for each specific operating condition while using common components.
2Measurement precision
If separate components are used for different signal paths to reduce signal interference, then signal resolution is improved, but device complexity, size, and cost increase
Solution Approach 1:
The patent makes common components universal by designing them to handle multiple frequency bands through dynamic configuration. The oscillator in the first signal path can generate different local oscillator signals by adjusting divider values, and the same oscillator can also serve the second signal path. This multi-functionality allows separate signal paths with optimized performance while avoiding the need for completely separate components for each frequency band.
3Productivity
If adjustable oscillator divider values are used to optimize frequency settings for each band, then signal processing efficiency is improved, but device complexity increases
Solution Approach 1:
The patent implements a feedback mechanism where the controller detects jammer frequencies and uses this information to dynamically adjust the oscillator divider values. The controller monitors the signal environment, identifies jammer frequencies, and selects appropriate divider values to optimize downconversion and avoid interference. This feedback loop enables efficient signal processing adapted to real-time conditions without requiring manual reconfiguration.
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 solution enables efficient, stable, and cost-effective processing of multiple GNSS signals by isolating in-band signals from jammer frequencies, optimizing receiver size, cost, and power usage while maintaining high resolution.
Implementation Method 1
mixing the first RF signal portion with the first local oscillator signal to generate a first intermediate frequency signal
Implementation Method 2
dividing a frequency of an oscillator signal by a first oscillator divider value to generate a first local oscillator signal
Implementation Method 3
filtering the second downconversion output signal to isolate an in-band signal from the jammer frequency
Data Source
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AI summary
A radio frequency (RF) receiver, for example a satellite positioning system receiver, can be configured to use a single phase locked loop for generating an oscillator signal to perform downconversion of signals in two different frequency bands using two or more local oscillators. A first RF signal portion includes a first signal band and undergoes double downconversion using a first mixer and a second mixer, while a second RF signal portion includes a second signal band and undergoes single downconversion using a single mixer. A controller is configured to determine a first oscillator divider value and a second oscillator divider value to avoid a jammer frequency and frequency dividers are used to generate the two or more local oscillators.