MOS Amplifier Phase Control During Gain Switching
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Solution Overview
Problem
Conventional variable gain amplifiers in 5G communications systems face challenges in maintaining a constant phase during gain adjustments, leading to increased bit error rates and antenna receiving angle changes, as existing solutions require separate phase compensation and increased layout area or fixed phase changes.
Innovation Solution
The proposed amplifier uses a configuration of MOS transistors where the gate of the first MOS transistor is coupled to both the signal input and bias voltage, and the drain of the third MOS transistor is connected to ground, allowing for flexible phase adjustment by controlling the conductive state of the third MOS transistor and adjusting the bias voltage to change transconductance, thereby maintaining a constant phase during gain switching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a digital switched attenuator with phase compensation component is used, then constant phase is achieved, but layout area and costs increase
Solution Approach 1:
The patent combines the phase compensation function with the gain control function into a single integrated circuit structure. The third MOS transistor (M3) serves dual purposes: it provides phase compensation while simultaneously enabling gain switching through its conductive state changes. This eliminates the need for separate phase compensation components, thereby reducing layout area while maintaining constant phase.
Solution Approach 2:
The third MOS transistor (M3) is designed to perform multiple functions: it acts as both a phase compensation element and a gain control switch. By controlling M3's conductive state, the circuit achieves both phase stabilization and gain adjustment in a single component, reducing overall circuit complexity and area.
2Adaptability or versatility
If active circuit with bias current switching is used, then gain switching is achieved, but phase cannot be kept constant
Solution Approach 1:
The patent employs a feedback mechanism where the bias voltage applied to the first MOS transistor (M1) is dynamically adjusted based on the state of the third MOS transistor (M3). When M3 switches states to change gain, the bias voltage is simultaneously adjusted to compensate for phase changes, ensuring constant phase is maintained during gain transitions.
Solution Approach 2:
The patent changes the bias voltage parameter dynamically to maintain constant phase during gain switching. By adjusting the bias voltage applied to M1 in response to M3's state changes, the circuit compensates for phase variations and maintains stable phase characteristics across different gain states.
3Stability of the object's composition
If phase compensation component is added, then constant phase is achieved, but device complexity increases
Solution Approach 1:
The patent merges the phase compensation function into the existing gain control circuitry by utilizing the third MOS transistor (M3) for both purposes. This integration eliminates the need for separate phase compensation components, thereby reducing device complexity while achieving constant phase.
Solution Approach 2:
The third MOS transistor (M3) is designed as a multi-functional element that provides both phase compensation and gain control capabilities. This universal approach reduces the total number of components required, simplifying the overall circuit design and reducing device complexity.
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 enables flexible phase adjustment and constant phase maintenance during gain changes, reducing bit error rates and antenna angle changes, while minimizing layout area and costs by eliminating the need for additional phase compensation components.
Implementation Method 1
a gate of the third MOS transistor is used to: under control of a second gate control signal, change a cut-off state or a conductive state of the third MOS transistor to perform bypass control on an alternating current signal
Implementation Method 2
the bias voltage input end is used to receive a bias voltage, so as to adjust a phase difference between an input signal at the signal input end and an output signal at the signal output end
Data Source
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AI summary
This application discloses an amplifier, an amplification circuit, and a phase shifter, and relates to the communications field, to flexibly adjust an output phase, thereby meeting a requirement of a constant phase on a link. The amplifier includes: a gate of a first MOS transistor is separately coupled to a signal input end and a bias voltage input end, a source of the first MOS transistor is coupled to a power supply; and a drain of the first MOS transistor is separately coupled to a source of the second MOS transistor and a source of the third MOS transistor, a drain of the third MOS transistor is coupled to the ground, and a drain of the second MOS transistor is coupled to a signal output end; a gate of the second MOS transistor makes the second MOS transistor in a conductive state under control of a first gate control signal; a gate of the third MOS transistor under control of a second gate control signal changes a cut-off state or a conductive state of the third MOS transistor bypass control on an alternating current signal output by the drain of the first MOS transistor. The bias voltage input end receives a bias voltage to adjust a phase difference between an input signal of the signal input end and an output signal of the signal output end.