RF Switching Circuit Using Opposed Diodes for Microsecond Switching
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Solution Overview
Problem
Existing RF switching circuits face challenges with slow switching speeds and large spatial requirements due to the use of RF suppressing elements, which also introduce energy storage and additional losses.
Innovation Solution
A switching circuit design utilizing a pair of diodes with opposite polarities in parallel signal paths to provide control signals, allowing for rapid switching and reducing the need for large RF suppressing components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If RF suppressing elements are used to isolate DC control signal path from RF signal path, then RF signal isolation is achieved, but switching speed is reduced and spatial requirements increase
Solution Approach 1:
The patent extracts the RF suppression function from traditional large inductors and capacitors and implements it using diodes with opposite polarities in parallel signal paths. This extraction allows the circuit to maintain RF isolation while achieving faster switching speeds and reduced component size, directly resolving the contradiction between reliable RF isolation and fast switching performance
2Reliability
If RF suppressing elements are used to isolate DC control signal path from RF signal path, then RF signal isolation is achieved, but device volume increases
Solution Approach 1:
The patent extracts the RF suppression function from traditional large inductors and capacitors and implements it using diodes with opposite polarities in parallel signal paths. This extraction allows the circuit to maintain RF isolation while achieving faster switching speeds and reduced component size, directly resolving the contradiction between reliable RF isolation and fast switching performance
Solution Approach 2:
The patent changes the impedance parameters of the signal paths by using diodes with opposite polarities, creating a configuration where RF frequencies are suppressed while DC control signals pass through. This parameter change enables compact component design that maintains isolation performance without requiring large physical volumes
3Reliability
If RF suppressing elements are used in control circuit, then RF signal isolation is achieved, but energy losses increase
Solution Approach 1:
The patent converts the potential harmful effect of RF signals leaking into the control path into a beneficial configuration where diodes with opposite polarities automatically block RF frequencies while allowing DC control signals to pass. This approach achieves RF isolation without the energy losses associated with traditional resistive or inductive suppression elements
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 achieves switching times of microseconds or less, with reduced impedance and spatial requirements, while maintaining efficient RF signal isolation.
Implementation Method 1
The control circuit comprises a first signal path, wherein the first signal path comprises at least one first diode being configured to provide the control signal to the switchable element
Implementation Method 2
The at least one second diode, which has opposite polarity compared to the at least one first diode, accelerates the switching at least from the on-state to the off-state, as the at least one second diode enables charge stored in the switchable element to be transported away from the switchable element quickly
Data Source
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AI summary
A switching circuit (10) for selectively closing or interrupting a radio frequency, RF, signal path (12) is described. The switching circuit (10) comprises a switchable element (20), wherein the switchable element (20) is switchable between an on-state and an off-state. The switching circuit (10) further comprises a control circuit (22) and a power supply module (24). The control circuit (22) is configured to apply a control signal provided by the power supply module (24) to the switchable element (20), wherein the control signal comprises a control voltage and/or a control current. The control circuit (22) comprises a first signal path (28), wherein the first signal path (28) comprises at least one first diode (32) being configured to provide the control signal to the switchable element (20). The control circuit (22) comprises a second signal path (30), wherein the second signal path (30) is arranged in parallel to the first signal path (28). The second signal path (30) comprises at least one second diode (40), wherein the at least one second diode (40) is arranged with opposite polarity compared to the at least one first diode (32). Further, an impedance tuning network is described.