EM Coupling Shielding via Negative Transconductance Ring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The increasing complexity and miniaturization of wireless communication devices make them more susceptible to electromagnetic (EM) coupling, which can lead to spurious signals and frequency pulling in RF circuits, destabilizing the transceiver and affecting the performance of wireless communication systems.
Innovation Solution
A ring structure is used to partially surround EM circuits, with a negative transconductance circuit coupled to its ends to cancel EM coupling by generating and tuning settings for the negative transconductance circuit and capacitors to neutralize the induced voltages, thereby shielding the EM circuits from unwanted coupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If wireless devices are miniaturized and circuits are placed in proximity to reduce device size, then device dimensions are reduced, but EM coupling between circuits increases causing spurious signals and frequency pulling
Solution Approach 1:
A ring structure is introduced as an intermediary element between the aggressor and victim circuits. The ring structure couples to both circuits and uses a negative transconductance circuit to generate a canceling signal that neutralizes the EM coupling interference, allowing close placement of circuits without suffering from harmful EM coupling effects
Solution Approach 2:
The negative transconductance circuit generates a canceling signal in advance that is equal in magnitude but opposite in phase to the EM coupling interference. This preliminary anti-action prevents the spurious signals and frequency pulling from occurring in the first place, rather than attempting to correct them after they occur
2Device complexity
If RF circuits are placed in proximity to increase circuit density, then device complexity is managed, but EM coupling causes spurious signals and frequency pulling that destabilize the transceiver
Solution Approach 1:
The ring structure serves as a mediator that monitors the EM coupling between aggressor and victim circuits. By coupling to both circuits and processing the interference through the negative transconductance circuit, it enables high circuit density while maintaining transceiver stability through active cancellation of EM coupling effects
Solution Approach 2:
The ring structure creates a feedback mechanism where EM coupling signals from both aggressor and victim circuits are captured and processed. The negative transconductance circuit uses this feedback information to generate a real-time canceling signal that maintains transceiver stability even at high circuit densities
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 solution effectively reduces EM coupling by canceling spurious voltages in EM circuits, improving the stability and performance of wireless communication systems by minimizing the impact of EM interference on the oscillation frequency of VCOs.
Implementation Method 1
cancel an EM coupling to the EM circuit at a frequency
Data Source
AI summary
A method and an apparatus for canceling EM coupling are provided. The apparatus includes a ring structure at least partially surrounding an EM circuit. A negative transconductance circuit is coupled to ends of the ring structure. The negative transconductance circuit is configured to cancel an EM coupling to the EM circuit at a frequency. The method includes generating a plurality of settings for a negative transconductance circuit and tuning the negative transconductance circuit to one of the plurality of settings for the negative transconductance circuit to cancel an EM coupling to an EM circuit at a frequency.