Multi-Tuner Local Oscillator Calibration With Reduced Interference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In receiving devices with multiple tuner units, noise occurs during local oscillator frequency searches due to interference between tuner units, degrading the reception quality of other units undergoing VCO calibration.
Innovation Solution
Incorporating a frequency divider, high-frequency processing unit, and control unit to distribute high-frequency signals and set non-operational components of the local oscillator to a dormant state during frequency searches, reducing signal leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If VCO calibration is performed to accurately ascertain control voltage for desired reception frequency, then measurement precision is improved, but noise leaks into other tuner units degrading reception quality
Solution Approach 1:
The patent divides the local oscillator into multiple independent parts: a VCO unit for frequency generation and a frequency divider unit for frequency division. During VCO calibration, only the VCO unit operates while the frequency divider unit is set to a dormant state, preventing noise leakage to other tuner units while maintaining calibration accuracy
Solution Approach 2:
The patent performs VCO calibration in advance when no other tuner units are actively receiving signals, or sets non-calibrating parts to dormant state before calibration begins. This preliminary positioning of components to appropriate states prevents interference with ongoing reception while enabling accurate calibration
2Productivity
If multiple tuner units operate simultaneously to enable parallel reception, then productivity is improved, but local oscillator frequencies interfere with each other
Solution Approach 1:
The patent segments the local oscillator functionality across separate units: one unit generates the local oscillator frequency while another unit performs frequency division. This segmentation allows multiple tuner units to operate simultaneously without mutual interference, as each unit's oscillator operations are spatially and functionally separated
Solution Approach 2:
The patent extracts the frequency division function from the local oscillator generation function, placing them in separate units. This extraction eliminates the interference problem by removing the source of noise (frequency division operations) from the same physical location as the sensitive local oscillator generation, enabling multiple units to coexist without interference
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 configuration minimizes noise in the received picture by shortening the duration of local oscillator frequency searches and reducing signal leakage to other tuner units, thereby enhancing reception quality.
Implementation Method 1
a local oscillator frequency generated by a local oscillator that includes a voltage-controlled oscillator
Implementation Method 2
outputs a received signal obtained by mixing the high-frequency signal distributed by the distributor with a local oscillator frequency
Data Source
AI summary
At least one distributor that distributes a high-frequency signal received by an antenna; and a high-frequency processing unit that outputs a received signal obtained by mixing the high-frequency signal distributed by the distributor with a local oscillator frequency generated by a local oscillator that includes a voltage-controlled oscillator are included. Furthermore, a control unit that, when executing a local oscillator frequency search to investigate a correspondence between a control voltage applied to the voltage-controlled oscillator and the local oscillator frequency of the voltage-controlled oscillator, sets to a dormant state parts constituting the local oscillator that are uninvolved in operation of the local oscillator frequency search is included.