RF Signal Blocking Device LC Resonance Circuit
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Solution Overview
Problem
Existing RF signal blocking devices, such as coils with a fuse function, may fail to effectively block high-frequency RF signals when the fuse line is fused due to overcurrent, causing capacitive or magnetic coupling and subsequent signal transmission.
Innovation Solution
An RF signal blocking device incorporating an LC resonance circuit with a capacitor unit and a second inductor having a fuse wire, where the resonant frequency shifts to block RF signals within a prescribed frequency band after the fuse wire is fused, utilizing a magnetic body to efficiently heat and fuse the wire, and configuring the circuit as either parallel or series to maximize impedance at the resonant frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fuse line is used to protect against overcurrent, then protection from short circuit current and overload is achieved, but RF signals may still be transmitted through the fused portion due to capacitive or magnetic coupling
Solution Approach 1:
The inductor is divided into two separate inductors (first inductor and second inductor) connected in parallel. The second inductor contains a fuse wire that can be selectively fused without affecting the first inductor, thereby segmenting the protection function from the RF signal path.
Solution Approach 2:
The fuse function is extracted from the single inductor structure and placed specifically in the second inductor. This allows the fuse wire to be fused for protection while the first inductor remains intact to block RF signals through magnetic coupling.
2Reliability
If a single inductor with fuse wire is used, then overcurrent protection is achieved, but the inductance is relatively large which limits frequency response
Solution Approach 1:
The single inductor is segmented into two parallel inductors, reducing the total inductance value. This lower inductance improves the frequency response and allows the device to operate effectively at higher frequencies while maintaining overcurrent protection capability.
3Ease of operation
If the resonant frequency is set above the prescribed frequency band, then signals in the prescribed band can pass through normally, but RF signals above the band are not blocked
Solution Approach 1:
The resonant frequency of the LC resonance circuit is made dynamic through the fuse mechanism. In normal operation, the resonant frequency is set above the prescribed band to allow signal passage. When overcurrent occurs and the fuse wire fuses, the resonant frequency shifts to block RF signals, providing adaptive protection based on operational conditions.
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 device reliably blocks RF signals in the prescribed frequency band by adjusting the resonant frequency of the LC resonance circuit, preventing signal transmission and protecting against damage from high-power RF signals.
Implementation Method 1
the second inductor including a fuse wire is fused when an RF signal having an RF power value greater than or equal to a predetermined level is inputted
Implementation Method 2
an LC resonance circuit including a capacitor unit that includes at least one capacitor and an inductor unit that includes a first inductor and a second inductor connected in parallel, and having a resonant frequency higher than the prescribed frequency band
Implementation Method 3
f=1/(2π(LC)1/2) based on capacitance (C) of the capacitor unit and inductance (L) of the inductor unit
Data Source
AI summary
An RF signal blocking device includes a capacitor unit and an inductor unit defining an LC resonance circuit. The capacitor unit and inductor unit are set such that a cutoff frequency in the LC resonance circuit after disconnection by fusing of a second inductor including a fuse wire, among first and second inductors of the inductor unit, fluctuates within a prescribed frequency band. The RF signal blocking device reliably blocks an RF signal in a prescribed frequency band after an abnormality of fusing in the second inductor including a fuse wire occurs due to an input of an RF signal having an RF power value greater than or equal to a predetermined level.