Frequency-Agile Band Select Filter With Dual-LO Channel Selection
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Solution Overview
Problem
Conventional radio frequency systems require multiple dedicated bandpass filters for each frequency channel, leading to increased size, weight, and power consumption, as well as limited flexibility and redundancy, due to thermal drift issues and the need for specific filter configurations.
Innovation Solution
The Frequency Agile Band Select Filter (FABSF) uses two separate signal generators and mixers with different local oscillator frequencies to enable frequency conversion between input and output frequencies, allowing for a single filter configuration to handle multiple channels and accommodating thermal drift through adjustable oscillator settings, thereby reducing the number of filters required and enhancing system flexibility and redundancy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple dedicated bandpass filters are used for each frequency channel, then channel selection precision is improved, but device complexity and quantity of components increase
Solution Approach 1:
A single bandpass filter is designed to handle multiple frequency channels by combining it with multiple signal generators and mixers. The filter operates universally across different frequency bands, eliminating the need for multiple dedicated filters while maintaining channel selection precision through software-controlled frequency translation.
Solution Approach 2:
The system changes the operational parameters of the filter by adjusting the local oscillator frequencies of the signal generators and mixers. This allows a single filter with fixed characteristics to effectively select different frequency channels by translating them to a common intermediate frequency, thereby reducing component quantity while preserving selection precision.
2Measurement precision
If multiple dedicated bandpass filters are used for each frequency channel, then channel selection precision is improved, but weight and volume increase
Solution Approach 1:
Multiple filter functions are merged into a single physical filter component. By combining the filter with multiple signal generators and mixers in an integrated architecture, the system achieves multi-channel filtering capability with a single filter unit, significantly reducing weight and volume while maintaining channel selection precision.
Solution Approach 2:
The single bandpass filter is designed to serve multiple frequency channels universally. Through frequency translation using signal generators and mixers, the filter handles different frequency bands, eliminating the need for multiple heavy filter components while preserving precise channel selection capability.
3Measurement precision
If multiple dedicated bandpass filters are used for each frequency channel, then channel selection precision is improved, but power consumption increases
Solution Approach 1:
The system merges multiple filter operations into a single filter component, reducing the total power consumption associated with running multiple independent filters. The integrated architecture with shared signal processing resources further optimizes energy efficiency while maintaining precise channel selection.
Solution Approach 2:
A single power-efficient filter is designed to handle multiple frequency channels through software-controlled frequency translation. This universal approach eliminates the redundant power consumption of multiple dedicated filters while preserving channel selection precision through intelligent signal processing.
4Stability of the object's composition
If multiple dedicated bandpass filters are used for each frequency channel, then thermal stability is improved, but adaptability decreases
Solution Approach 1:
The system compensates for thermal drift by dynamically adjusting the local oscillator frequencies of the signal generators and mixers. This parameter adjustment approach maintains thermal stability of the single filter while providing adaptability to compensate for frequency shifts, eliminating the need for multiple temperature-compensated filters.
Solution Approach 2:
The system employs feedback mechanisms to monitor and correct for thermal drift effects on the filter's center frequency. By adjusting the local oscillator frequencies based on detected frequency shifts, the system maintains stable channel selection across temperature variations while preserving adaptability to different operating conditions.
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 FABSF minimizes size, weight, and power consumption while providing flexible channel selection and improved thermal stability, allowing for efficient operation across multiple channels with reduced spectral occupancy and increased robustness against component obsolescence.
Implementation Method 1
an input mixer in communication with the first signal generator and configured to receive the first transposition signal and a radio frequency (RF) input at a first frequency within an first RF band, the input mixer configured to output a frequency-converted RF input based on mixing the RF input with the first transposition signal
Data Source
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AI summary
A filter, apparatus, system and method are provided for implementing a band select filter, for example a frequency agile band select filter. In an implementation, the filter includes two separate signal generators configured to provide different local oscillator signals to an input mixer and to an output mixer, resulting in the filter output frequency being different from the filter input frequency. This is in contrast to known approaches which use the same signal generator to drive both input and output mixers. The filter may include two bandpass filters, three mixers, and three signal generators, each signal generator uniquely associated with one of the mixers, and configured to provide bandwidth control. A system of filters may include a set of bandpass filters, a plurality of sets of mixers, and a plurality of sets of signal generators, each set of signal generators being associated with a different set of mixers.