Wireless Circuitry Coexistence Using Conjugate RF Filters
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Solution Overview
Problem
Existing wireless communications circuitry in electronic devices face interference issues when multiple radio access technologies (RATs) operate concurrently, particularly when accessing the same frequency bands, leading to deteriorated performance without adequate filter reconfiguration.
Innovation Solution
The implementation of conjugate filters, including switched notch filters and switched bandpass filters, allows concurrent communication across overlapping frequency bands without the need for additional resource allocation or filter reconfiguration, ensuring coexistence of different RATs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple radio access technologies operate concurrently on the same frequency bands, then wireless communication capabilities are enhanced, but signal interference increases and performance deteriorates
Solution Approach 1:
The frequency spectrum is segmented into different bands (e.g., first band for first RAT, second band for second RAT) using filter circuitry. Each RAT is assigned specific frequency segments to operate independently, preventing interference while maintaining multi-RAT capabilities. The transmission line paths are divided into multiple segments with dedicated filters for each RAT.
Solution Approach 2:
Filter circuitry acts as an intermediary between different RAT transmission paths. The filters (including notch filters and bandpass filters) mediate the frequency separation, allowing concurrent operations by blocking interfering frequencies from reaching each other's transmission paths while permitting desired signals to pass.
2Reliability
If filter reconfiguration is implemented to prevent interference between RATs, then signal quality improves, but system complexity and resource allocation requirements increase
Solution Approach 1:
Filter circuitry is pre-configured with fixed frequency responses during device manufacturing. Notch filters are pre-set to reject specific interfering bands, and bandpass filters are pre-configured to pass desired RAT frequencies. This preliminary configuration eliminates the need for complex real-time reconfiguration, reducing system complexity while maintaining reliable interference prevention.
Solution Approach 2:
The filter circuitry is designed to handle multiple RATs simultaneously with a single unified filter structure. The same filter network serves both first RAT and second RAT paths, providing universal interference protection across different frequency bands without requiring separate reconfigurable filter sets for each RAT.
3Device complexity
If fixed filter configurations are used to simplify the system, then device complexity is reduced, but adaptability to different frequency bands is limited
Solution Approach 1:
Different portions of the frequency spectrum are assigned different fixed filter characteristics optimized for specific RATs. The first transmission line path has filters optimized for first RAT frequency bands, while the second path has filters optimized for second RAT bands. Each local filter configuration is tailored to its specific frequency region, providing simple yet effective frequency-specific adaptation.
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 simultaneous and efficient operation of multiple RATs within the same frequency range by minimizing interference, thereby enhancing wireless performance and data throughput.
Implementation Method 1
The wireless circuitry may include a switched notch filter on the first transmission line path and a switched bandpass filter on the second transmission line path. The switched notch filter may be a conjugate of the switched bandpass filter, in which a stopband of the switched notch filter overlaps a passband of the switched bandpass filter.
Data Source
AI summary
An electronic device may have wireless circuitry that includes transceiver circuitry, first and second antennas, and first and second transmission line paths that couple the transceiver circuitry to the antennas. The transceiver circuitry may convey a first radio-frequency signal using a first radio access technology (RAT) over the first transmission line path and the first antenna and may concurrently convey a second radio-frequency signal using a second RAT over the second transmission line path and the second antenna. The wireless circuitry may include a switched notch filter on the first transmission line path and a switched bandpass filter on the second transmission line path. The switched notch filter may be a conjugate of the switched bandpass filter. The transceiver circuitry may scan the first radio-frequency signal over a set of bands while concurrently conveying the second radio-frequency signal without reconfiguring the filters.