Coupled Line System With Controllable Impedance for Low Insertion Loss
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Solution Overview
Problem
Current coupled line systems for radio-frequency technology face challenges in achieving low insertion loss and minimizing nonlinear distortions and video crosstalk, especially at high frequencies, due to parasitic inductances and capacitances, and require wideband coupling capacitors that are difficult to realize without frequency limitations.
Innovation Solution
A line system with coupled lines where controllable elements are arranged along the lines to vary the characteristic impedance and complex propagation constant, allowing for a weak coupling and low insertion loss across a wide frequency range, including multiple-digit gigahertz frequencies, without the need for wideband coupling capacitors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If switching elements are disposed exclusively at the inputs and outputs of the line system, then the structure is simplified, but insertion loss increases at very high frequencies due to parasitic inductances and capacitances
Solution Approach 1:
The patent divides the line system into multiple sections with switching elements distributed along the transmission lines rather than concentrated only at inputs and outputs. This segmentation reduces the impact of parasitic inductances and capacitances at any single point, thereby reducing insertion loss at very high frequencies while maintaining structural organization.
Solution Approach 2:
The patent applies different impedance characteristics to different sections of the transmission lines. By creating local variations in impedance (strong coupling in some sections, weak coupling in others), the system optimizes signal transmission at specific locations to minimize parasitic effects at high frequencies while maintaining overall structural simplicity.
2Loss of energy
If strong coupling between lines is used to achieve low insertion loss, then signal transmission is improved, but device complexity and difficulty of realization increase significantly
Solution Approach 1:
The patent employs controllable elements that can dynamically adjust the coupling strength between transmission lines based on operating conditions. This dynamic adjustment allows the system to achieve low insertion loss when needed while simplifying the overall structure by using weak coupling as the default state, thereby reducing realization difficulty.
Solution Approach 2:
The patent changes the coupling parameter between transmission lines from a fixed strong coupling to a variable parameter that can be adjusted between strong and weak coupling modes. This parameter change enables the system to achieve low insertion loss through controlled strong coupling in specific sections while maintaining structural simplicity through weak coupling in other sections.
3Object-affected harmful factors
If coupling capacitors are inserted at inputs and outputs to prevent DC voltage transmission, then DC isolation is achieved, but the lower limit frequency cannot be zero and DC voltage cannot be transmitted
Solution Approach 1:
The patent removes the coupling capacitors from the input and output terminals of the line system. By extracting these capacitive elements, the system achieves DC voltage transmission capability across the entire frequency range from zero to high frequencies, while DC isolation is maintained through the inherent properties of the transmission line structure and controllable elements.
4Ease of operation
If switching elements are disposed at the output line as well, then switching path selection is completed, but video crosstalk increases due to voltage peaks caused by DC control voltage changes
Solution Approach 1:
The patent introduces controllable elements with adjustable impedance as intermediary components between the switching elements and the transmission lines. These intermediary elements act as buffers that reduce voltage peaks caused by DC control voltage changes, thereby minimizing video crosstalk while maintaining the switching path selection functionality.
Solution Approach 2:
The patent adjusts the impedance parameter of controllable elements along the transmission lines to optimize switching performance. By changing the impedance characteristics in different sections, the system reduces video crosstalk from voltage peaks while maintaining effective switching path selection, achieving both ease of operation and reduced harmful factors.
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 solution enables low insertion loss and low nonlinear distortions, allowing for the flexible transmission of both DC-voltage and high-frequency signals with reduced video crosstalk, using a weak coupling between lines and adjustable impedance to optimize signal propagation.
Implementation Method 1
The lines extend in spatial proximity and are coupled. The at least two lines transport an electromagnetic signal fed into the line system.
Implementation Method 2
controllable elements are arranged along the lines to vary the characteristic impedance and complex propagation constant
Data Source
AI summary
The invention relates two lines each with two terminals. A first line provides a first terminal and a second terminal. A second line provides a first terminal and a second terminal. The lines extend in spatial proximity and are coupled. The two lines transport an electromagnetic signal fed into the line system. Distanced from the first terminal of the second line and distanced from the second terminal of the second line, at least one controllable element is arranged along the second line. The invention further relates to a switch, a controllable diplexer, a controllable frequency filter, a controllable attenuator and a controllable phase shifter.