RF MEMS Phase Shifter Using Stiffness-Tuned Capacitance Bridges
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional phase shifters suffer from high power consumption, high insertion loss, poor reliability, and high cost, while existing RF MEMS phase shifters face complexity in structure due to the need for individual signal transmission lines and control circuits for each capacitance bridge.
Innovation Solution
A phase shifter design featuring a substrate with a signal transmission line, ground wires, and capacitance bridges that span the signal line, where the capacitance bridges have varying critical bias voltages and bending stiffness, allowing for controlled phase shifts through electrostatic drive responses without individual control circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional phase shifters use silicon diodes, field effect transistors or ferrite devices, then phase adjustment function is achieved, but power consumption is high, insertion loss is high, reliability is poor and cost is high
Solution Approach 1:
The patent replaces traditional electronic components (silicon diodes, field effect transistors, ferrite devices) with an RF MEMS-based mechanical system. The phase shifter uses a MEMS switch with movable contact that can be positioned between different capacitor banks, substituting electronic phase control with a mechanical switching mechanism that has lower power consumption and higher reliability.
2Measurement precision
If RF MEMS phase shifter uses multiple capacitance bridges with individual control circuits, then phase shift control precision is improved, but device structure complexity increases
Solution Approach 1:
The patent combines multiple capacitance bridges into a single integrated RF MEMS switch structure. Instead of having separate control circuits for each capacitance bridge, the design uses one movable contact that can switch between multiple fixed contacts, each connected to different capacitor banks. This merging reduces the number of control circuits from multiple to one, significantly simplifying the overall device structure while maintaining precise phase shift control capability.
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 design simplifies the structure by eliminating the need for individual control circuits and enables precise control of phase shifts through varying bias voltages, reducing complexity and enhancing reliability and efficiency.
Implementation Method 1
critical bias voltages are different when capacitance between the different capacitance bridges and the signal transmission line reaches the maximum
Implementation Method 2
After removing the bias voltage, the capacitance bridge returns to an initial position due to its own elasticity
Data Source
AI summary
Provides are a phase shifter and a communication apparatus. The phase shifter includes a substrate; a signal transmission line on one side of the substrate; a first ground wire and a second ground wire on the same side of the substrate as the signal transmission line, the first and second ground wires are on two sides of the signal transmission line; and capacitance bridges on one side away from the substrate, of a layer where the signal transmission line is, the capacitance bridges are connected with the first and second ground wires, the capacitance bridges span the signal transmission line and are sequentially arrayed in an extension direction of signal transmission line, there is a gap between the capacitance bridges and the signal transmission line in a direction perpendicular to substrate, critical bias voltages are different when capacitance between the capacitance bridges and the signal transmission line reaches the maximum.