Cross-Coupled Switch Circuit for Leakage Cancellation
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Solution Overview
Problem
Switch leakage in wireless communication devices, particularly at high frequencies, leads to undesirable effects in circuits due to unintended current flow, which existing technologies have not adequately addressed.
Innovation Solution
A circuit design incorporating a transmission switch and a dummy switch, where the dummy switch is cross-coupled to the output of the transmission switch, allowing leakage currents of opposite polarity to cancel each other out, thereby reducing or eliminating leakage effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If electronic switches are used in transmitters or receivers, then signal routing and gain control are enabled, but leakage current occurs when switches are off, leading to undesirable circuit effects
Solution Approach 1:
The patent introduces a dummy switch that generates a leakage current equal in magnitude but opposite in polarity to the transmission switch's leakage current. This converts the harmful leakage effect into a beneficial cancellation mechanism, where the dummy switch's 'harmful' leakage actively neutralizes the transmission switch's leakage, achieving net zero leakage at the output.
Solution Approach 2:
The dummy switch acts as an intermediary element between the transmission switch and the output circuit. It mediates the leakage current by providing an opposing current path that cancels the unwanted leakage, allowing the transmission switch to maintain its signal routing function without suffering from leakage penalties.
2Speed
If switches are used at high frequencies, then wireless communication performance is improved, but leakage current becomes large enough to cause undesirable effects
Solution Approach 1:
The dummy switch converts the high-frequency leakage phenomenon into a beneficial effect by generating an opposing leakage current. Instead of treating leakage as an unavoidable penalty of high-frequency operation, the invention harnesses it through the dummy switch to achieve active cancellation, allowing high-frequency operation without leakage penalties.
Solution Approach 2:
The invention changes the polarity parameter of the leakage current by using a dummy switch configured with opposite polarity characteristics. This parameter change transforms the leakage from a unidirectional harmful effect into a bidirectional cancellation system where positive and negative leakage currents neutralize each other at the output.
Data Source
AI summary
In accordance with embodiments of the present disclosure, a circuit may include a transmission switch and a dummy switch coupled at its output to the output of the transmission switch. The transmission switch may be configured to be selectively enabled and disabled based on a control signal received at a gate of the transmission switch. The transmission switch may be further configured to receive a first polarity of a differential signal at its input and pass the first polarity of the differential signal to its output when enabled. The dummy switch may be configured to be disabled and to receive a second polarity of the differential signal at its input, the second polarity of opposite polarity of the first polarity.