High-Frequency Switch Circuit Reducing Signal Distortion
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Solution Overview
Problem
High-frequency switch circuits used in wireless communication systems experience signal distortion due to large amplitude input signals, particularly in the microwave band, which existing configurations fail to mitigate effectively with simple circuit configurations.
Innovation Solution
A high-frequency switch circuit design incorporating a first switch with a transmission line, diode, capacitance element, and charging/discharging circuit, and a second switch with a diode and capacitance element, controlled by complementary control signals to manage signal connections between an antenna and input/output terminals, reducing distortion by maintaining diode bias states and adjusting capacitance element potentials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a simple high-frequency switch circuit configuration is used, then device complexity is reduced, but signal distortion increases when large amplitude signals are input
Solution Approach 1:
The patent applies preliminary action by pre-charging a capacitance element to a specific voltage level before the switching operation. This pre-prepared state enables the circuit to quickly respond to large amplitude input signals without causing distortion, as the capacitance is already in the correct state to handle the signal transition. The control circuit charges the capacitance element in advance based on the switching requirement.
Solution Approach 2:
The patent implements dynamics by making the bias voltage applied to the diode dynamically adjustable through the control circuit. The capacitance element's voltage is changed according to the switching state and input signal characteristics. This dynamic adjustment allows the circuit to adapt to varying signal amplitudes, preventing distortion while maintaining simple overall circuit structure.
2Loss of information
If the capacitance element voltage is increased to prevent diode turn-on during high amplitude signals, then signal distortion is reduced, but energy consumption increases
Solution Approach 1:
The patent applies periodic action by charging the capacitance element only when needed for switching operations rather than maintaining continuous high voltage. The control circuit periodically adjusts the capacitance voltage based on the switching state and signal requirements. This periodic charging reduces average energy consumption while still preventing diode turn-on during high amplitude signals when necessary.
Solution Approach 2:
The patent implements parameter changes by dynamically adjusting the capacitance element voltage level according to the specific operating conditions. Instead of maintaining a fixed high voltage, the control circuit modifies the capacitance voltage parameter based on the switching state and input signal amplitude. This adaptive parameter adjustment reduces energy consumption while effectively preventing distortion.
3Device complexity
If a diode is used for switching in the high-frequency signal path, then device complexity is reduced, but signal distortion occurs when the diode turns on during high amplitude signals
Solution Approach 1:
The patent applies preliminary action by pre-charging the capacitance element to establish the correct bias condition before the high-frequency signal passes through the diode. This pre-prepared voltage state ensures the diode remains in the desired conduction state during the switching operation, preventing unwanted turn-on that would cause signal distortion. The simple diode structure is thus made reliable through this preliminary voltage preparation.
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 effectively reduces signal distortion across a wide range of input signal amplitudes by stabilizing diode bias states and managing capacitance element potentials, maintaining low impedance for signal transmission while preventing diode turn-on during high amplitudes, thus ensuring minimal signal loss and distortion.
Implementation Method 1
a diode having an anode connected to a first node between the transmission line and the input terminal, and a cathode connected to a second node
Implementation Method 2
a capacitance element connected to the second node and a first power supply voltage
Implementation Method 3
a first inductor element connected in series between the first node and the first control terminal
Data Source
AI summary
A high-frequency switch circuit includes a first switch configured to electrify or cut off connection between an antenna terminal and an input terminal, and a second switch configured to electrify or cut off connection between the antenna terminal and an output terminal. The first switch has a transmission line connecting the antenna terminal and the input terminal; a diode having an anode connected to a first node between the transmission line and the input terminal, and a cathode connected to a second node; and a capacitor connected to the second node and a first power supply voltage. A first control terminal is connected to the first node via a first resistor and a first inductor. The first switch further includes a charging/discharging circuit connected to a second power supply voltage and the first control terminal and charging and discharging the capacitor from the second node.