Circulator-Based Reflective RF Filter for Wideband Reconfiguration
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Solution Overview
Problem
Existing wireless communication systems struggle to operate effectively over a wide range of frequencies, particularly in microwave communication systems that require reconfigurable filters to handle different frequencies efficiently.
Innovation Solution
A reconfigurable wideband high-frequency filter using a non-reciprocal circulator, comprising at least one non-reciprocal circulator and multiple reflective filter elements, including amplitude change reflectors with N-path filters, which modify RF signal amplitudes at different frequencies through switches and capacitors, allowing selective control of signal paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional filters are used in wireless communication systems, then the system can operate at specific frequencies, but the system cannot operate effectively over a wide range of frequencies
Solution Approach 1:
The filter employs dynamic reconfiguration capabilities through varactor diodes and switching mechanisms that allow the filter characteristics (center frequency, bandwidth, Q-factor) to be changed electronically. This enables a single filter structure to adapt to multiple frequency ranges, resolving the contradiction between wide frequency adaptability and device complexity by making the filter parameters dynamically adjustable rather than fixed
Solution Approach 2:
The invention changes physical parameters of the filter (capacitance values, inductance values, coupling coefficients) to achieve different frequency responses. By using varactor diodes whose capacitance can be tuned via voltage control, and switches that reconfigure the circuit topology, the filter can operate across a wide frequency range without requiring multiple separate filter devices, thus improving adaptability while managing complexity
2Adaptability or versatility
If multiple filters are used to cover different frequencies, then the frequency coverage is improved, but the device complexity and size increase
Solution Approach 1:
The filter design achieves multi-functionality by incorporating reconfigurable elements that allow a single filter structure to perform multiple filtering functions across different frequency bands. The circulator-based architecture with switchable and tunable components enables the same physical filter to serve multiple frequency coverage requirements, eliminating the need for multiple separate filters and reducing overall device complexity
Solution Approach 2:
The invention merges multiple filter functions into a single integrated structure using a circulator with shared resonant circuits. The circulator allows multiple filter paths to coexist and be selectively activated, combining the functionality of what would traditionally require separate filters into one unified device, thereby improving frequency coverage while reducing component count
3Reliability
If reflective filter elements are used with circulator, then the filtering performance is improved, but the signal path complexity increases
Solution Approach 1:
The circulator acts as an intermediary device that manages the signal paths between the input, output, and reflective filter elements. It provides isolation between different signal paths and enables controlled reflection without requiring complex direct connections between filter elements, thus improving filtering performance while managing signal path complexity through the mediating circulator structure
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
Enables highly reconfigurable and linear filtering across a wide frequency range, supporting applications in high-power wireless communications and devices like 5G base stations, with the ability to adapt filter elements dynamically for desired frequency responses.
Implementation Method 1
at least one non-reciprocal circulator
Implementation Method 2
each of the amplitude change reflectors comprises an N-path filter having multiple paths, each path comprising a switch and a capacitor
Implementation Method 3
multiple reflective filter elements. Each reflective filter element is configured to receive a radio frequency, RF, signal from the at least one non-reciprocal circulator and to provide a filtered RF signal to the at least one non-reciprocal circulator
Data Source
Figure 1~2
Figure 3A~3B
Figure 4
AI summary
A method includes receiving (506) a radio frequency (RF) input signal (108) using at least one non-reciprocal circulator (102, 402). The method also includes generating (510) an RF output signal (110) using at least one of multiple reflective filter elements (104a-104n, 404a-404b). Each reflective filter element is configured to receive an RF signal from the at least one non-reciprocal circulator and to provide a filtered RF signal to the at least one non-reciprocal circulator. The reflective filter elements include amplitude change reflectors configured to modify amplitudes of the RF signal at different frequencies. The RF output signal represents the RF input signal as modified (508) by the at least one of the reflective filter elements.