Transceiver Circuit Tunable Low-Pass Filter RF Disturbance
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Solution Overview
Problem
Transceiver circuits in communications networks face challenges with low electromagnetic emission (EME) and radio frequency (RF) electromagnetic disturbance, leading to bit errors due to impedance variations and direct current (DC) shifts, which existing open-loop circuits cannot effectively compensate for.
Innovation Solution
A transceiver circuit with a feedback loop and tunable low-pass filter, connected to a control circuit that detects RF disturbances and adjusts bandwidth to mitigate high-frequency interference, using a high-pass filter and RF-to-DC converter to generate control signals, ensuring adaptive filtering and low EME.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a typical open-loop transceiver circuit uses waveshaping to control transition time and amplitude, then low electromagnetic emission is achieved, but the circuit cannot compensate for impedance variations on the communications bus
Solution Approach 1:
The patent implements a feedback loop that continuously monitors the communications bus and adjusts the output voltage accordingly. The feedback circuit receives a portion of the output signal and uses it to compensate for impedance variations on the bus, allowing the transceiver to maintain low electromagnetic emission while adapting to changing bus conditions.
Solution Approach 2:
The patent employs dynamic adjustment of the output voltage waveform based on real-time bus conditions. The transceiver circuit continuously adapts its waveshaping characteristics in response to detected impedance variations, transitioning from static open-loop control to dynamic closed-loop control to maintain optimal performance.
2Device complexity
If a typical open-loop transceiver circuit operates without feedback, then the circuit structure is simple, but DC shift on the communications bus leads to bit errors
Solution Approach 1:
The patent introduces a feedback mechanism that monitors the communications bus for DC shifts and adjusts the output voltage to compensate. The feedback loop detects bus conditions and dynamically adjusts the transmitter output to prevent DC accumulation that would cause bit errors, thereby improving reliability without excessive complexity increase.
Solution Approach 2:
The patent implements preliminary DC compensation by detecting potential DC shift conditions before they cause bit errors. The feedback circuit proactively adjusts the output waveform to prevent DC accumulation on the bus, addressing the issue before it impacts transmission reliability.
3Device complexity
If the transceiver circuit uses fixed bandwidth filtering, then the circuit design is straightforward, but it cannot adaptively protect from high-frequency disturbances of varying amplitude
Solution Approach 1:
The patent implements a dynamically adjustable low-pass filter with variable bandwidth controlled by a microcontroller. The filter bandwidth is adaptively adjusted based on the amplitude of high-frequency disturbances detected on the bus, allowing the transceiver to optimize its filtering performance in response to changing electromagnetic interference conditions.
Solution Approach 2:
The patent changes the bandwidth parameter of the low-pass filter dynamically based on detected disturbance levels. The microcontroller monitors high-frequency disturbances and adjusts the filter bandwidth parameter accordingly, narrowing the bandwidth when disturbances are strong and widening it when conditions are calm, thereby adaptively protecting against interference.
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AI summary
Embodiments of transceiver circuits and methods for operating a transceiver circuit are described. In one embodiment, a transceiver circuit includes a feedback loop connected to a bus and a control circuit connected to the bus. The feedback loop includes a tunable low-pass filter. The control circuit is configured to detect a radio frequency (RF) disturbance on the bus and control the bandwidth of the tunable low-pass filter in response to detection of the RF disturbance on the bus. Other embodiments are also described.