Lumped Equivalent Impedance Transformer for Compact Phase Shifting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Phase shifting devices using liquid crystals face scalability issues as frequency decreases, resulting in excessively long microstrip lines that are impractical for lower gigahertz operations, necessitating a compact solution without compromising performance.
Innovation Solution
Implementing a lumped equivalent impedance transformer circuit using liquid crystal variable capacitors and standard inductors, which allows for adjustable phase shifting without the need for lengthy microstrip lines, decoupling size from frequency and enabling a compact design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If liquid crystal microstrip lines are used for phase shifting, then phase shift control is achieved, but device size becomes excessively large at lower gigahertz frequencies
Solution Approach 1:
The patent divides the microstrip line into discrete lumped element segments (inductors and capacitors) that can be independently controlled. This segmentation allows the phase shifting function to be distributed across multiple compact components rather than requiring a single long continuous microstrip line, thereby reducing the overall device footprint while maintaining phase control capability
Solution Approach 2:
The patent replaces the physical microstrip line structure with an equivalent lumped element circuit model. By substituting the distributed electromagnetic structure with discrete circuit elements (inductors and capacitors), the design achieves the same electrical function in a compact form factor, eliminating the direct proportionality between operating frequency and physical length
2Length of stationary object
If device size is reduced using lumped elements, then compactness is achieved, but bandwidth may be limited
Solution Approach 1:
The patent employs voltage-tunable liquid crystal capacitors that can dynamically adjust their capacitance values in response to control voltages. This dynamic tunability allows the lumped element circuit to adapt its electrical characteristics across a broad frequency range, compensating for the inherent bandwidth limitations of compact lumped element structures and enabling operation over wide bandwidths despite the reduced physical size
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 provides a compact, scalable phase shifting device capable of achieving significant phase shifts over broad bandwidths with manageable insertion losses, maintaining performance across varying frequencies.
Implementation Method 1
the voltage tunability of the dielectric properties of liquid crystals can be utilised in a phase shifting device
Implementation Method 2
the voltage tunability of the dielectric properties of liquid crystals can be utilised in a phase shifting device
Data Source
AI summary
A phase shifting device is disclosed. The phase shifting device comprises an input operable to receive an input signal to be adjusted; a coupling device coupled with the input and with an output; and at least one lumped equivalent impedance transformer circuit coupled with the coupling device to receive the input signal, the lumped equivalent impedance transformer circuit having liquid crystal variable capacitors operable to adjust the input signal in response to a bias voltage applied thereto and to provide the adjusted input signal to the coupling device as an output signal. Rather than using a microstrip structure, a lumped element equivalent is instead used, which makes it possible to exploit the advantages of a liquid crystal structure but in a more compact form.