MEMS Film-Bridge Phase Shifter for Continuous RF Phase Control
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Solution Overview
Problem
Conventional MEMS phase shifters have limited phase adjustment capability due to fixed capacitance switching between turn-on and turn-off states, restricting continuous phase adjustment of radio frequency signals.
Innovation Solution
A phase shifter design featuring a substrate with signal lines, ground lines, and a capacitance adjusting component with a film bridge and dielectric pillars made of ferroelectric materials, allowing continuous capacitance adjustment with bias voltage, enabling linear correlation and improved phase shifting capability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional MEMS phase shifters use fixed capacitance switching between turn-on and turn-off states, then the device structure is simple and manufacturing is easy, but the phase adjustment capability is limited and cannot achieve continuous phase adjustment
Solution Approach 1:
The patent transforms the fixed capacitance switching mechanism into a dynamic, continuously adjustable capacitance system. By introducing a movable bridge structure that can be positioned at different locations along the signal line through voltage control, the capacitance value becomes variable rather than fixed. This dynamic adjustment capability enables continuous phase adjustment while maintaining a relatively simple overall device structure.
Solution Approach 2:
The patent changes the capacitance parameter from a fixed value to a continuously variable parameter. By controlling the position of the bridge structure through applied voltage, the capacitance between the bridge and the signal line can be adjusted continuously. This parameter change enables the phase shifter to achieve continuous phase adjustment capability while keeping the device structure manageable.
2Reliability
If ferrite phase shifters are used to achieve large power capacity and small insertion loss, then the phase shifting performance is improved, but the process complexity increases, manufacturing cost rises, and volume increases
Solution Approach 1:
The patent replaces the ferrite material-based electromagnetic phase shifting mechanism with a MEMS-based mechanical/electrical hybrid system. Instead of using ferrite materials that require complex manufacturing processes, the invention uses a movable bridge structure with capacitive coupling to achieve phase shifting. This substitution maintains good phase shifting performance while significantly simplifying the manufacturing process and reducing device complexity.
Solution Approach 2:
The patent changes the operating principle from ferrite material properties to capacitive coupling effects. By utilizing the voltage-controlled capacitance variation between the bridge and signal line, the system achieves phase shifting without requiring ferrite materials or complex electromagnetic processes. This parameter change enables simplified manufacturing while maintaining reliability.
3Volume of moving object
If semiconductor phase shifters are used to achieve small volume and high operating speed, then the device size is reduced and speed is improved, but the power capacity becomes small, power consumption increases, and manufacturing difficulty increases
Solution Approach 1:
The patent employs a dynamic bridge structure that can be positioned at different locations to achieve phase adjustment. This mechanical/electrical hybrid approach allows the device to maintain a compact form factor similar to semiconductor devices while achieving higher power capacity through the robust MEMS structure. The voltage-controlled positioning mechanism enables high operating speed without sacrificing power handling capability.
Solution Approach 2:
The patent uses a composite structure combining conductive bridge material, dielectric layers, and substrate materials. This composite approach enables the device to achieve small volume through miniaturization while maintaining high power capacity through the robust construction of the bridge and substrate assembly. The composite structure also facilitates efficient heat dissipation, supporting higher power operation.
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 phase shifter achieves continuous phase adjustment of radio frequency signals, enhancing phase shifting capability compared to conventional MEMS phase shifters by allowing variable capacitance adjustment with bias voltage, thereby improving phase control precision and reducing manufacturing costs.
Implementation Method 1
the capacitance adjusting component is configured to adjust a capacitance between the film bridge and the signal line to a target capacitance when the capacitance adjusting component receives a bias voltage
Implementation Method 2
the signal line is in a space enclosed by the film bridge and the substrate
Implementation Method 3
the capacitance adjusting component further includes a plurality of dielectric pillars vertically on a surface of the signal line proximal to the bridge floor structure
Implementation Method 4
each of the plurality of dielectric pillars includes a ferroelectric material
Data Source
AI summary
A phase shifter and an antenna device are provided. The phase shifter includes a substrate, a signal line on the substrate, ground lines in pairs on the substrate, and a capacitance adjusting component. Two ground lines in a same pair of ground lines are on both sides of the signal line and spaced apart from the signal line, respectively. The capacitance adjusting component includes a film bridge, and both ends of the film bridge are on the two ground lines, respectively. The signal line is in a space enclosed by the film bridge and the substrate. The capacitance adjusting component is configured to adjust a capacitance between the film bridge and the signal line to a target capacitance when the capacitance adjusting component receives a bias voltage, and the target capacitance has a linear correlation with a magnitude of the bias voltage.