Double-Y Balun Phase Shifter With Switchable Stubs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional phase shifters are limited in bandwidth, with phase shifters greater than 45 degrees typically restricted to 4:1 bandwidths and multi-octave 180-degree phase shifters limited to 3:1 bandwidths, necessitating the use of time-delay circuits for applications exceeding these limits.
Innovation Solution
A phase shifter incorporating a double-y balun with switchable stubs, utilizing symmetry changes in the double-y junction to achieve 180-degree phase shifting, implemented with field effect transistors (FETs) or microelectromechanical systems (MEMS) switches, allowing for high bandwidth operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional phase shifters are used to achieve greater than 45 degrees phase shift, then phase shifting capability is improved, but bandwidth is limited to 4:1
Solution Approach 1:
The patent employs switchable stubs that can dynamically change their electrical length and impedance characteristics. By switching between different stub configurations (open/closed states), the phase shifter can achieve 180-degree phase shift while maintaining broadband operation across 20:1 bandwidth, resolving the contradiction between phase shifting capability and bandwidth limitation.
Solution Approach 2:
The invention changes the electrical parameters (impedance, electrical length) of the transmission path by switching stub configurations. This allows the system to achieve different phase shifts (including 180 degrees) while maintaining consistent broadband performance, overcoming the 4:1 bandwidth limitation of conventional phase shifters.
2Measurement precision
If multi-octave 180 degree phase shifters are used, then phase shifting capability is improved, but bandwidth is limited to 3:1
Solution Approach 1:
The patent uses dynamically switchable stubs that can change their state to achieve 180-degree phase shift. This dynamic reconfiguration allows the system to maintain 3:1 or better bandwidth performance while achieving full 180-degree phase shift capability, resolving the limitation of conventional multi-octave phase shifters.
Solution Approach 2:
The phase shifter is segmented into multiple independent switchable stubs (first and second stubs with different impedance values). By independently controlling the state of each stub, the system can achieve precise 180-degree phase shift while maintaining broadband operation, overcoming the 3:1 bandwidth limitation.
3Adaptability or versatility
If time-delay circuits are used to exceed bandwidth limits, then bandwidth is improved, but device complexity increases
Solution Approach 1:
The switchable stub structure serves multiple functions: it provides phase shifting capability, bandwidth extension, and impedance matching all within a single integrated structure. This eliminates the need for separate time-delay circuits, achieving broadband operation without increasing device complexity.
Solution Approach 2:
The invention merges the phase shifting function and bandwidth extension function into a single switchable stub structure. By combining these functions, the system achieves 20:1 bandwidth with 180-degree phase shift capability without requiring additional complex time-delay circuitry.
Data Source
AI summary
A balun includes: a balanced port; an unbalanced port; and a double-y junction portion between the balanced port and the unbalanced port, the double-y junction portion including: a balanced y junction portion having first and second balanced stubs; and an unbalanced y junction portion having first and second unbalanced stubs, wherein at least one of the first balanced stub, the second balanced stub, the first unbalanced stub, and the second unbalanced stub includes a switch.