Transformer-Based Phase Shifter for Low Loss mmWave Operation
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Solution Overview
Problem
Existing RF phase shifters face challenges with high insertion loss, impractically small component values, and large physical layout at higher frequencies, especially in the range of mm waves, due to their reflective nature.
Innovation Solution
A phase shifter circuit utilizing a transformer and switchable conduction paths, including a reflective SPDT switch, which operates in multiple modes to provide low loss and wideband frequency operation by selectively coupling ports through low or high impedance paths, eliminating the need for passive reactive components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If reflective phase shifter topology is used, then phase shifting capability is achieved, but insertion loss increases significantly
Solution Approach 1:
The patent inverts the conventional reflective phase shifter topology by using a forward-transmission configuration instead. The phase shifter uses forward transmission through the device rather than reflection, which fundamentally changes the signal path and reduces insertion loss while maintaining phase shifting capability.
Solution Approach 2:
The patent changes the operating parameters by using a different topological configuration that operates in forward transmission mode. This parameter change from reflection-based to transmission-based operation allows the phase shifter to achieve lower insertion loss while maintaining the required phase shifting function.
2Manufacturing precision
If conventional reactive components are used at mm wave frequencies, then phase shifting is achieved, but component values become impractically small
Solution Approach 1:
The patent replaces conventional reactive components (inductors and capacitors) with a transmission line-based topology. This substitution eliminates the need for impractically small reactive component values at mm wave frequencies by using distributed transmission line elements that are more feasible to manufacture and maintain at these frequencies.
Solution Approach 2:
The patent changes the fundamental parameters by transitioning from lumped reactive components to distributed transmission line parameters. This allows the phase shifter to operate at mm wave frequencies with practical component dimensions and manufacturing tolerances while maintaining the required phase shifting capability.
3Area of stationary object
If reflective phase shifter design is used, then phase shifting function is achieved, but physical layout size increases
Solution Approach 1:
The patent segments the phase shifter into two independent 90-degree phase shift sections. Each section contributes 90 degrees of phase shift, and when combined, they provide the required 180-degree total phase shift. This segmentation allows for a more compact physical layout compared to a single reflective section while maintaining the required phase shifting performance.
Solution Approach 2:
The patent inverts the conventional reflective design by using forward transmission through two cascaded sections. This inverted topology reduces the physical layout size by eliminating the need for large reflective paths and associated matching networks, while maintaining the required phase shifting function through the cascaded transmission line sections.
4Adaptability or versatility
If wideband operation is achieved, then frequency range is improved, but insertion loss increases
Solution Approach 1:
The patent changes the topological parameters to a forward-transmission configuration that inherently provides lower insertion loss across a wide frequency range. This parameter change allows the phase shifter to maintain wideband operation while reducing insertion loss compared to conventional reflective designs, as the transmission-based topology is more efficient across broad frequency ranges.
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 achieves reduced insertion loss, a more compact design, and robust operation up to 300 GHz, with lower power consumption and reduced physical layout size, while maintaining efficient phase shifting capabilities.
Implementation Method 1
a first transformer having a first winding and a second winding, the first winding coupled to the second port and the third port
Data Source
AI summary
A low loss, wide band, phase shifter utilizing one or more transformers in presented. In one case, the phase shifter includes a reflective SPDT switch that is coupled to a transformer. In another case, the phase shifter includes a distributed SPDT switch that includes switchable conduction paths having series connected unit elements of a same phase shift. The transformer may be part of an existing circuit and may be reused to provide the functionality of the phase shifter by introducing the reflective or the distributed SPDT switch.