Passive Phase Shifter Circuit With Constant Impedance Switching
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Solution Overview
Problem
Conventional phase shifter circuits in transceiver systems experience impedance variation when phase is changed by switching capacitor or inductor values, leading to changes in input and output impedances.
Innovation Solution
The implementation of a phase shifter circuit that correlates characteristic impedance and phase, allowing for a phase change by switching capacitance or inductance values while maintaining a constant characteristic impedance, using a bidirectional, linear, and passive circuit topology, suitable for integrated circuit technologies, and capable of scalable phase shifts without affecting input and output port impedances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If phase is changed by switching capacitor or inductor values, then phase shift is achieved, but characteristic impedance changes causing input and output impedance variation
Solution Approach 1:
The patent applies parameter changes by simultaneously adjusting both capacitance and inductance values when switching phase states. Instead of changing only one parameter (which causes impedance variation), the invention coordinates changes in both L and C parameters to maintain constant characteristic impedance while achieving the desired phase shift, directly resolving the technical contradiction.
Solution Approach 2:
The patent employs preliminary action by pre-calculating and pre-setting the correlated L and C values for each desired phase state. The phase shifter is designed with predetermined LC pairs that are optimized in advance to maintain constant impedance, allowing the circuit to switch between pre-optimized states without impedance variation.
2Adaptability or versatility
If conventional phase shifting method is used, then phase change is achieved, but input and output impedances vary
Solution Approach 1:
The invention changes the approach by simultaneously modifying both inductance and capacitance parameters in a coordinated manner. For each phase state, specific L and C values are selected together to maintain constant characteristic impedance, making impedance matching automatic and eliminating the need for additional matching circuits or adjustments.
3Productivity
If capacitor or inductor values are switched for phase change, then phase shifting is achieved, but characteristic impedance varies
Solution Approach 1:
The patent uses preliminary action by pre-designing and pre-calculating the correlated L and C values for each phase state during the manufacturing process. The phase shifter is built with predetermined LC pairs that are optimized in advance to maintain constant impedance across all phase states, ensuring impedance consistency is built into the hardware design rather than requiring post-manufacturing adjustment.
Data Source
AI summary
An apparatus includes a plurality of transceiver circuits, each comprising one or more phase shifter circuits. The phase shifter circuits may be configured to make a phase change by switching at least one of a capacitance value and an inductance value in response to a control signal. A characteristic impedance and the phase of each phase shifter circuit are correlated such that after the phase change, a value of the characteristic impedance is maintained at a predefined value.