Active 90-Degree Phase Shifter With Coupler-Multiplexer Architecture
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional phase shifters, such as active vector-modulators and distributed passive switched-LC phase shifters, suffer from high noise figures, low linearity, and insertion loss, which become more pronounced at higher frequencies, and require complex amplifiers to compensate for losses, increasing power dissipation and chip area.
Innovation Solution
The implementation of a phase-invariant, active nominal 90-degree phase shifter using a coupler to generate in-phase and quadrature signal components, and an active circuit with a multiplexer to achieve precise phase shifting with low power dissipation, reducing the need for high-resolution digital-to-analog converters and minimizing insertion loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If active vector-modulators are used for implementing a phase shifter, then phase shifting functionality is achieved, but noise figure increases and linearity decreases
Solution Approach 1:
The patent replaces the conventional active vector-modulator approach with a passive switched-LC network approach. Instead of using active components (VMs) that suffer from high noise and low linearity, the invention uses passive LC tanks and switches to achieve phase shifting through resonant frequency selection, thereby eliminating the noise and linearity problems associated with active modulators.
Solution Approach 2:
The patent changes the operating parameters by using multiple LC tanks with different resonant frequencies (e.g., 90-degree phase steps) and switching between them. This parameter-based approach allows precise phase control without the degradation in noise figure and linearity that plagues active VM implementations.
2Loss of energy
If distributed passive switched-LC phase shifters are used, then insertion loss is reduced, but device complexity increases due to requirements for low FOM switches
Solution Approach 1:
The patent divides the phase shifter into multiple independent LC tank segments, each tuned to a specific resonant frequency corresponding to a particular phase shift value. By segmenting the phase shifting function across multiple resonant tanks rather than using a single complex switched network, the design achieves low insertion loss while simplifying the switch requirements, as each switch only needs to handle simple tank selection rather than complex FOM optimization.
3Loss of energy
If amplifiers are used to compensate for loss from passive shifters, then signal loss is compensated, but power dissipation and chip area increase
Solution Approach 1:
The patent converts the potential harm of insertion loss into a benefit by designing LC tanks with high quality factors (Q) that naturally minimize energy dissipation. Instead of adding amplifiers to compensate for losses, the invention uses the resonant properties of the LC tanks themselves to maintain signal strength, thereby achieving loss compensation without the additional power dissipation and chip area that amplifiers would require.
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
This solution achieves robust and precise phase shifting with reduced power dissipation and insertion loss, enabling efficient operation at higher frequencies without the need for complex amplifiers, thus optimizing chip area and performance.
Implementation Method 1
a phase-invariant, active nominal 90-degree phase shifter... a coupler that generates, from an input signal, a first signal at a first coupler output and a second signal at a second coupler output
Data Source
AI summary
Aspects of this disclosure are directed to phase shifters, inclusive of an active 90-degree phase shifter. A phase shifter of this disclosure may include a coupler that generates, from an input signal, a first signal at a first coupler output and a second signal at a second coupler output, a first plurality of transistors coupled to the first coupler output, and a second plurality of transistors coupled to the second coupler output. The first plurality of transistors and the second plurality of transistors may form a multiplexer that implements a nominal 90-degree phase shift in an output signal in accordance with a selection via a control signal. Other aspects and embodiments are disclosed.