Echo Cancellation via Adjustable Capacitor Delay Control
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Solution Overview
Problem
Conventional communication devices fail to effectively address the phase difference between positive-end and negative-end signals of differential signals, leading to intra-pair skew and electromagnetic interference noise, particularly in complex circuit board layouts.
Innovation Solution
A communication device comprising a digital circuit, transmitter circuit, hybrid circuit, adjustable capacitor circuit, and receiver circuit, which controls the delay difference between positive-end and negative-end signals using echo cancellation control signals to reduce intra-pair skew and echo, and includes adjustable phase-shifting and resistor circuits for impedance matching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional communication devices transmit differential signals through complex circuit board layouts, then communication functionality is maintained, but phase difference between positive-end and negative-end signals increases causing intra-pair skew and electromagnetic interference noise
Solution Approach 1:
The patent applies preliminary action by measuring and adjusting the delay difference between positive-end and negative-end signals before actual communication occurs. The adjustable capacitor circuit is configured to control the delay difference based on measured values, ensuring signals are synchronized prior to transmission, thereby preventing intra-pair skew and electromagnetic interference noise that would otherwise result from complex circuit board layouts
Solution Approach 2:
The patent changes the electrical parameter of signal delay by introducing adjustable capacitor circuits that can modify the delay difference between differential signals. By adjusting capacitance values based on measured delay differences, the system compensates for path length variations in complex circuit board layouts, maintaining signal integrity without requiring simplified routing
2Adaptability or versatility
If the routing layout of circuit board is complex, then device functionality is achieved, but delay difference between positive-end and negative-end signals increases leading to intra-pair skew
Solution Approach 1:
The patent implements feedback by measuring the actual delay difference between positive-end and negative-end signals in the complex circuit board layout and using this measurement to adjust the capacitor circuits. The system continuously monitors signal timing and modifies capacitance values to compensate for routing variations, maintaining precise signal timing despite complex routing requirements
Solution Approach 2:
The patent applies dynamics by making the capacitor circuit values adjustable rather than fixed. The delay compensation capability dynamically adapts to the specific routing characteristics of the circuit board, allowing the system to optimize signal timing precision for complex layouts without compromising device functionality
3Reliability
If adjustable capacitor circuits are added for delay control, then intra-pair skew is reduced, but device complexity increases
Solution Approach 1:
The patent applies partial action by implementing delay compensation only for the critical differential signal paths that exhibit significant delay differences. Rather than complicating the entire system, adjustable capacitor circuits are selectively placed where needed to correct intra-pair skew, achieving improved echo cancellation performance with minimal additional complexity
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 effectively reduces intra-pair skew and electromagnetic interference noise, enhancing echo cancellation capabilities in communication devices, especially in scenarios with impedance mismatches.
Implementation Method 1
The adjustable capacitor circuit is configured to control a delay difference between a positive-end signal and a negative-end signal of the transmission signal according to a first echo cancellation control signal
Implementation Method 2
The hybrid circuit is coupled to the transmitter circuit and receiver circuit, and configured to output a transmission signal to an external circuit via the adjustable capacitor circuit according to the analog transmission differential signal and output an analog reception differential signal to the receiver circuit
Data Source
AI summary
A communication device capable of echo cancellation includes a digital circuit, a transmitter circuit, a hybrid circuit, an adjustable capacitor circuit, and a receiver circuit. The digital circuit transmits a digital transmission signal and receives a digital reception signal. The transmitter circuit outputs an analog transmission differential signal according to the digital transmission signal. The hybrid circuit outputs a transmission signal to an external circuit via an adjustable capacitor circuit according to the analog transmission differential signal, and outputs an analog reception differential signal to a receiver circuit according to at least one of the analog transmission differential signal and a reception signal from the external circuit. The adjustable capacitor circuit controls a delay difference between positive-end and negative-end signals of the transmission signal according to an echo cancellation control signal. The receiver circuit outputs the digital reception signal to the digital circuit according to the analog reception differential signal.