Switched All-Pass Phase Shifter for Adjustable Band Phase Control
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Solution Overview
Problem
Existing phase shifters have a uniquely determined frequency characteristic and phase-shift error in desired frequency bands, limiting flexibility in achieving a desired amount of phase shift.
Innovation Solution
A phase shifter design incorporating first and second all-pass filters with specific element configurations and switching switches, allowing for impedance matching and adjustable phase shift through free variables, enabling flexible frequency characteristics in desired frequency bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a combination of lumped-parameter elements is used in all-pass filters, then the circuit structure is simple and easy to manufacture, but the frequency characteristic of the amount of phase shift is uniquely determined and cannot be adjusted to achieve desired phase shift in desired frequency bands
Solution Approach 1:
The patent applies parameter changes by introducing a transformation circuit that converts impedance parameters between different frequency points. This allows the phase shifter to adjust its frequency characteristic by transforming the impedance parameters of the all-pass filters, thereby achieving desired phase shift amounts in desired frequency bands while maintaining the simple lumped-parameter element structure for ease of manufacture.
2Device complexity
If the phase shifter uses fixed lumped-parameter elements, then the device complexity is low, but the phase-shift error is uniquely determined and a desired amount of phase shift cannot be obtained
Solution Approach 1:
The patent introduces a transformation circuit as an intermediary component between the fixed lumped-parameter elements and the output. This transformation circuit acts as a mediator that adjusts the impedance parameters dynamically, enabling precise phase shift control without requiring complex fixed elements, thus reducing device complexity while improving phase-shift accuracy.
3Reliability
If conventional all-pass filter designs are used, then the matching condition is satisfied, but the frequency characteristic is fixed and cannot be optimized for specific frequency bands
Solution Approach 1:
The patent applies dynamics by making the impedance parameters of the all-pass filters adjustable through the transformation circuit. This allows the phase shifter to dynamically adapt its frequency characteristic to optimize performance for specific frequency bands while maintaining the matching condition, thereby achieving both reliability and frequency characteristic adjustability.
Data Source
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AI summary
A phase shifter (1) is configured in such a manner that the phase shifter (1) includes a first all-pass filter (11) including a plurality of elements; a second all-pass filter (12) including a plurality of elements; a first switching switch (13) that provides a signal to either one of the first all-pass filter (11) and the second all-pass filter (12); and a second switching switch (14) that selects the signal having passed through the first all-pass filter (11) or the signal having passed through the second all-pass filter (12), and the first all-pass filter (11) includes two inductors and three capacitors as the plurality of elements, and the second all-pass filter (12) includes two inductors and three capacitors as the plurality of elements, or the first all-pass filter (11) includes three inductors and two capacitors as the plurality of elements, and the second all-pass filter (12) includes three inductors and two capacitors as the plurality of elements, and element values of the plurality of elements included in the first all-pass filter (11) and element values of the plurality of elements included in the second all-pass filter (12) are determined by impedance at which impedance matching is achieved, a frequency of the signal, and a variable.