Stacked Amplifier Bias Circuit for High Off-State Impedance
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Solution Overview
Problem
Existing stacked amplifiers in electronic circuits suffer from fixed impedance issues, leading to significant losses and reduced performance when state switching is required, particularly for high-frequency signals.
Innovation Solution
Implementing a stacked amplifier with transistors that have adjustable impedance through a bias circuit using a variable capacitive or inductive device, allowing for high impedance in the off state without the need for additional switch components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a switch component is added to perform state switching in the stacked amplifier circuit, then the circuit can achieve state switching capability, but the circuit loss increases and high-frequency signal performance deteriorates
Solution Approach 1:
The patent removes the additional switch component from the circuit by utilizing the stacked amplifier's inherent impedance characteristics. The off impedance of the stacked amplifier structure itself provides the necessary state switching capability without requiring external switch components, thereby eliminating the associated losses and performance degradation.
Solution Approach 2:
The stacked amplifier structure serves multiple functions: it provides signal amplification in the on state and presents high off impedance in the off state. This multi-functionality eliminates the need for separate switch components, as the amplifier structure itself performs both amplification and switching functions.
2Adaptability or versatility
If a switch component is added to perform state switching in the stacked amplifier circuit, then the circuit can achieve state switching capability, but the high-frequency signal performance is greatly reduced
Solution Approach 1:
The patent extracts and eliminates the additional switch component that degrades high-frequency performance. The stacked amplifier's natural off impedance provides the switching function without introducing the parasitic elements and losses associated with external switch components, thereby preserving high-frequency signal integrity.
3Device complexity
If the transistor impedance in the stacked amplifier is fixed, then the amplifier structure is simple, but the off impedance cannot meet the requirement for state switching
Solution Approach 1:
The patent utilizes the dynamic impedance characteristics of the stacked amplifier structure. By controlling the operating state of the stacked amplifier, the off impedance can be dynamically adjusted to meet switching requirements without changing the physical structure of the amplifier, maintaining simplicity while achieving adaptability.
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 reduces circuit losses and enhances performance for high-frequency signals by ensuring high impedance in the off state, thereby improving bidirectional port performance without additional switches.
Implementation Method 1
the variable capacitance circuit may selectively change capacitance thereof based on a capacitance control signal applied thereto
Data Source
Figure 1A~1B
Figure 1C~1D
Figure 1E~2
AI summary
A stacked amplifier, a radio frequency transceiver circuit, a device, and a switching control method are disclosed. The stacked amplifier includes a first transistor (41), a second transistor (42), and a bias circuit (43). A bias end of the first transistor (41) is grounded, and an output end of the first transistor (41) is connected to an input end of the second transistor (42). A bias end of the second transistor (42) receives a bias voltage through the bias circuit (43). The bias circuit (43) includes a bias resistor and a variable impedance device. This can implement a high impedance in an off state, and reduce a bidirectional loss of a circuit.