Multi-Band Receiver Multiplexing to Simplify Satellite Downconversion
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Solution Overview
Problem
Current satellite ranging system receivers are complex and bulky due to the need for separate downconverter stages for each frequency band, leading to increased cost, size, and complexity, especially when handling multiple satellite systems and Controlled Reception Pattern Antennas (CRPA) with multiple antenna elements.
Innovation Solution
A multiplexed single analog/dual frequency receiver architecture that uses a single downconversion stage and A/D converter to efficiently sample both L1 and L2 signals, and can accommodate multiple satellite systems by time domain multiplexing signals, reducing the number of required downconverter stages and A/D converters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate downconverter stages are used for each frequency band, then signal processing accuracy is maintained, but device complexity and size increase
Solution Approach 1:
The patent merges multiple frequency band processing into a single downconverter stage by time-division multiplexing different frequency bands in separate time slots, allowing one downconverter to handle multiple bands (L1, L2, L5, etc.) sequentially, thereby reducing the number of downconverter stages from multiple to one while maintaining signal processing accuracy
Solution Approach 2:
The patent implements periodic switching between different frequency bands using a multiplexer that alternates between L1, L2, L5 and other bands in a cyclic manner, with each band being processed in its designated time slot before switching to the next band, enabling single downconverter to serve multiple bands periodically
2Reliability
If separate downconverter stages are used for each frequency band, then signal processing reliability is maintained, but cost and size increase
Solution Approach 1:
The patent makes a single downconverter stage universal by designing it to process multiple frequency bands through time-division multiplexing, where the same downconverter circuit is reused across different time slots for different bands, eliminating the need for dedicated downconverters for each band and reducing overall circuit count while maintaining reliability
Solution Approach 2:
The patent introduces dynamic time-division multiplexing control that dynamically allocates the single downconverter resource to different frequency bands based on which bands are currently active or needed, allowing flexible adaptation to different operational scenarios while maintaining signal processing reliability
3Object-affected harmful factors
If multiple antenna elements are used in CRPA, then jamming resistance is improved, but mutual coupling between elements increases
Solution Approach 1:
The patent extracts the signal processing function from multiple parallel analog channels and consolidates it into a single time-division multiplexed channel, where signals from multiple antenna elements are sequentially switched through one downconverter rather than being processed simultaneously through multiple downconverters, reducing mutual coupling while maintaining jamming resistance
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 approach simplifies the receiver architecture, reduces space and cost, and allows for processing of multiple signal bands with minimal increase in complexity, while also reducing mutual coupling between antenna elements in CRPA systems.
Implementation Method 1
The down conversion can be performed by 'heterodyning,' which involves mixing the incoming signal with one or more locally generated carrier reference signals to produce the signal with a selected intermediate frequency (IF).
Implementation Method 2
This analog IF signal is then converted to digital samples by an A/D converter.
Data Source
AI summary
A multi-band receiver for use with satellite ranging systems is provided. The receiver has a simplified architecture in which input signals of various frequencies are multiplexed together to form a single composite analog signal. In accordance with one embodiment of the invention, this composite signal only requires a single RF circuit for down conversion to an intermediate frequency. The composite, downconverted signal is sampled, and the digitized samples are demultiplexed to form digital counterparts of the original signals from each frequency band. An embodiment for use with elements of a phased array antenna is also provided.