Broadcast Input Impedance Switching for Low Return Loss
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Solution Overview
Problem
Conventional broadcast receiving apparatuses face issues with impedance mismatch between cable and input impedance, leading to increased return loss and noise in broadcast networks, especially when amplifying weak signals, which affects signal quality and network management costs.
Innovation Solution
A broadcast receiving apparatus with an impedance matching circuit and controller that adjusts input impedance based on reception mode and signal strength, ensuring optimal impedance values to minimize return loss and enhance signal amplification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the input impedance value is increased to amplify weak broadcast signals, then the signal amplification capability is improved, but the return loss increases due to impedance mismatch with the cable
Solution Approach 1:
The patent implements dynamic impedance adjustment by switching between different impedance values based on the reception mode (cable/antenna) and signal strength conditions. The controller dynamically selects appropriate impedance values to optimize both signal amplification and return loss performance for different operating scenarios.
Solution Approach 2:
The patent changes the input impedance parameter according to different reception modes and signal strength conditions. By adjusting the impedance value from a first value (for cable mode with strong signals) to a second value (for cable mode with weak signals) or third value (for antenna mode), the system optimizes the balance between signal amplification and return loss.
2Object-affected harmful factors
If the input impedance is matched to the cable to reduce return loss, then the return loss is reduced, but the amplification capability for weak signals is limited
Solution Approach 1:
The system dynamically adjusts impedance based on whether the signal is strong or weak. When signals are weak, the impedance is adjusted to prioritize amplification capability even if return loss increases slightly. When signals are strong, impedance is optimized for minimal return loss.
Solution Approach 2:
The patent changes impedance parameters based on signal strength measurements. For weak signals, a second impedance value is used that provides higher amplification. For strong signals, a first impedance value is used that minimizes return loss.
3Device complexity
If a fixed impedance value is used for all reception modes, then the device complexity is reduced, but the signal quality and return loss performance deteriorate in specific modes
Solution Approach 1:
The patent implements mode-based dynamic impedance selection where the controller determines the reception mode (cable or antenna) and automatically selects appropriate impedance values. This provides optimized performance for each mode without requiring complex continuous adjustment mechanisms.
Solution Approach 2:
The impedance matching circuit is designed to serve multiple functions: it handles both cable and antenna reception modes, adapts to different signal strength conditions, and optimizes performance across various operating scenarios through a single unified control mechanism.
Data Source
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AI summary
The present disclosure relates to a broadcast receiving apparatus. The broadcast receiving apparatus according to an embodiment of the present disclosure includes an impedance matching circuit configured to adjust an input impedance value of the broadcast receiving apparatus; and a controller, wherein, the controller controls the impedance matching circuit so that the input impedance value is adjusted to a certain reference impedance value, when a mode of the broadcast receiving apparatus is a mode of receiving a broadcast signal through a cable, and controls the impedance matching circuit so that the input impedance value is adjusted to be less than the certain reference impedance value, when the mode of the broadcast receiving apparatus is not the mode of receiving the broadcast signal through the cable. Accordingly, it is possible to appropriately amplify a broadcast signal while satisfying a reference related to return loss, thereby reducing network management cost of a network operator and providing a broadcast image of better quality to a user. In addition, various embodiments are possible.