Coreless Transformer Receiver Circuit Stray Capacitance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional coreless transformers with short decay time constants and high cut-off frequencies face challenges in signal transmission due to limitations in receiver circuit design, including manufacturing inaccuracies, high input capacitance, and susceptibility to electromagnetic interference, which restrict signal bandwidth and reliability.
Innovation Solution
A signal transmission arrangement featuring a transformer with a receiver circuit having a differential input resistance approximating a short circuit, utilizing transadmittance amplifiers and a voltage source to convert current pulses to voltage signals, thereby minimizing the impact of stray capacitance and inductance, and employing a storage circuit for reliable two-value signal processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the channel lengths of CMOS transistors are shortened to achieve high upper cut-off frequency, then the processing speed is improved, but manufacturing precision deteriorates causing threshold fluctuations
Solution Approach 1:
The patent introduces a metallic shield as an intermediary element between the primary and secondary windings. This shield acts as a mediator that redistributes electromagnetic fields and reduces the direct coupling of high-frequency signals with the CMOS transistor gates, thereby allowing shorter channel lengths without proportionally increasing manufacturing-induced threshold variations.
Solution Approach 2:
The patent changes the electrical parameters of the receiver circuit by introducing the metallic shield, which modifies the effective capacitance and inductance seen by the CMOS transistors. This parameter transformation allows the circuit to operate at higher frequencies while the shield's distributed structure helps average out local manufacturing variations in transistor thresholds.
2Reliability
If receiver circuits are designed with high input capacitance to improve signal detection, then sensitivity is improved, but signal bandwidth is limited due to low-pass filter effects
Solution Approach 1:
The metallic shield serves as an intermediary that decouples the high-input-capacitance receiver circuit from the transformer's stray inductance. By positioning the shield between the windings and the receiver input, it creates an electromagnetic barrier that reduces the effective inductance seen by the receiver, thereby extending the bandwidth despite the high input capacitance.
Solution Approach 2:
The patent converts the harmful effect of stray inductance (which forms a low-pass filter with input capacitance) into a beneficial configuration. The metallic shield redistributes the magnetic flux and reduces the effective stray inductance, transforming what would be a bandwidth-limiting factor into a component that can be managed or even exploited for improved coupling at higher frequencies.
3Object-affected harmful factors
If a metallic shield is added between primary and secondary windings to reduce interference, then electromagnetic shielding is improved, but secondary stray capacitance increases limiting signal bandwidth
Solution Approach 1:
The metallic shield is not implemented as a solid continuous structure but rather with localized openings or segmented sections. This local quality modification allows the shield to provide electromagnetic protection in critical areas while maintaining electromagnetic transparency in other areas, thereby reducing secondary stray capacitance effects and preserving signal bandwidth.
Solution Approach 2:
The patent employs thin metallic shield structures that provide electromagnetic shielding through their conductive properties while minimizing their capacitive coupling effect. The thin-film nature of the shield reduces the parasitic capacitance to the secondary winding compared to thick shield structures, allowing bandwidth preservation while maintaining interference protection.
4Volume of moving object
If coreless transformers are miniaturized to reduce size, then device compactness is improved, but lower cut-off frequency increases reducing signal bandwidth
Solution Approach 1:
The metallic shield acts as an intermediary that compensates for the increased cut-off frequency caused by miniaturization. By reducing the effective stray inductance and optimizing the magnetic coupling path, the shield allows the miniaturized transformer to maintain lower cut-off frequencies that would otherwise be higher due to the reduced dimensions.
Solution Approach 2:
The patent changes the electrical parameters of the transformer system by introducing the metallic shield, which modifies the effective inductance and resistance values. This parameter transformation allows the miniaturized transformer to achieve a lower cut-off frequency than would be expected from its physical dimensions alone, effectively decoupling size reduction from cut-off frequency increase.
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 enhances signal bandwidth by reducing the effect of stray capacitance and inductance, allowing for reliable detection of short voltage pulses and maintaining high processing speed, even with very short current pulses, thus improving the reliability and efficiency of signal transmission.
Implementation Method 1
transformers, in particular integrated coreless transformers, to be used to transmit signals between DC-decoupled circuits
Implementation Method 2
The receiver circuit is configured to convert a current pulse received at the input via the secondary winding to a voltage provided at the at least one output
Data Source
AI summary
A signal transmission arrangement includes a transformer and a receiver circuit. The transformer has at least one primary winding and at least one secondary winding, each having first and second connections. The receiver circuit is connected to the secondary winding, and has an input and at least one output. The receiver circuit also has a differential input resistance approximating a short circuit. The receiver circuit is configured to convert a current pulse received at the input via the secondary winding to a voltage provided at the at least one output.