Slow-Wave W-Band Phase Shifter for Compact Low-Loss Arrays
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Solution Overview
Problem
Existing phase shifters for millimeter wave operations in the W band are large in size and suffer from high losses, limiting their application in miniaturized phased array systems.
Innovation Solution
A passive phase shifter design utilizing a slow-wave transmission line with a patterned ground shield, multiple signal lines, and tunable blocks connected by switches, which allows for precise control of phase shift while minimizing device size and losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If conventional transmission lines are used for W band phase shifters, then the device can operate at the required frequency, but the device size becomes large
Solution Approach 1:
The patent changes the physical parameters of the transmission line by introducing a patterned ground shield with periodic structures. This modifies the effective permittivity and impedance characteristics of the line, slowing down the phase velocity to achieve compact dimensions while maintaining W band operation. The periodic patterning creates a slow-wave effect that reduces the wavelength on the transmission line.
Solution Approach 2:
The patent employs a composite structure combining patterned metal ground shields with dielectric layers and signal conductors. This composite transmission line structure achieves both size reduction and controlled impedance characteristics by integrating multiple materials and geometric patterns work together to create the slow-wave effect.
2Adaptability or versatility
If more blocks are added to increase phase shift control, then phase shift tuning capability improves, but device complexity increases
Solution Approach 1:
The phase shifter is divided into multiple discrete blocks along the transmission line, each capable of being independently controlled by switches. This segmentation allows flexible phase shift tuning by selectively activating different blocks, providing adaptability while maintaining a modular structure that manages complexity.
Solution Approach 2:
The patent implements dynamically controllable phase shifting by using switches to selectively connect or disconnect blocks from the signal path. This dynamic control allows the phase shift amount to be adjusted in real-time based on operational requirements, enhancing adaptability without permanently increasing structural complexity.
3Ease of operation
If switches are positioned within the signal path for block control, then phase shift control is achieved, but signal losses increase
Solution Approach 1:
The switches are extracted from the main signal path and positioned to control the connection of blocks to the transmission line from the side. This extraction minimizes the number of switch components that the signal must pass through, reducing insertion losses while maintaining full phase shift control capability.
Solution Approach 2:
The patent uses the patterned ground shield and dielectric structures as intermediary elements that facilitate block control without requiring switches directly in the signal path. The electromagnetic coupling between blocks and the transmission line is mediated through these passive structures, reducing the need for invasive switching mechanisms.
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 achieves a compact phase shifter with tunable phase shift capabilities, reducing losses and enabling efficient operation in phased array systems for radar and communication applications.
Implementation Method 1
a patterned ground shield comprising a plurality of elongate slots extending perpendicular to a longitudinal axis of the signal line. Compared to a standard coplanar line, a patterned ground shield comprising a plurality of elongate slots has a so called 'slow-wave effect' which helps to slow down the phase velocity of the signal and boosts the capacitance as well as the inductive contribution
Implementation Method 2
a signal line comprising an intermediate signal line and a top signal line connected by one or more conductive vias beneficially doubles the signal along the transmission line
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
An embodiment of passive phase shifter comprises a ground shield, a pair of ground walls electrically connected to the ground shield having a first height above the ground shield; and a signal line positioned between the ground walls and electrically isolated from the ground shield. The signal line may comprise an intermediate signal line separated a second height above the ground shield; a top signal line separated from the intermediate signal line at a third height above the ground shield and electrically connected to the intermediate signal line by one or more conductive vias; and a plurality of blocks positioned between and electrically isolated from the intermediate signal line and the top signal line.