Conjugate RF Filters for Multi-RAT Coexistence and Band Scanning

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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 resources.

Innovation Solution

The implementation of conjugate filters, including switched notch and bandpass filters, allows concurrent communication across the same frequency range for different RATs without the need for additional reconfiguration resources, ensuring coexistence and efficient band scanning.

Engineering Contradictions & Design Principles

VSEngineering 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

Engineering Contradiction:

Improvemulti-RAT communication capabilityVSAvoidsignal interference

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The frequency spectrum is segmented into different bands (e.g., first band, second band, third band) that are allocated to different RATs. The transceiver circuitry is divided into multiple independent transceivers, each dedicated to a specific RAT and operating on assigned frequency bands, thereby preventing interference while maintaining multi-RAT functionality

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Each transmission line path is equipped with dedicated filtering components (bandpass filters for one RAT, notch filters for another RAT) that provide localized frequency selectivity. This ensures that each RAT receives only its designated frequency components, eliminating cross-RAT interference while preserving overall system versatility

Inventive Principle:

Principle #3Local quality

2Reliability

If filter reconfiguration resources are added to prevent interference between RATs, then signal quality improves, but device complexity increases

Engineering Contradiction:

Improvesignal qualityVSAvoidfilter reconfiguration resources

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Frequency allocation is predetermined and assigned to specific RATs before operation begins. Transceiver 1 is permanently assigned to first and second bands, while transceiver 2 is assigned to third band. This preliminary assignment eliminates the need for dynamic filter reconfiguration, maintaining signal quality through dedicated filtering while avoiding the complexity of reconfiguration resources

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Instead of using a single transceiver that switches between different RATs and frequency bands (which would require complex reconfiguration), the patent inverts the approach by using multiple simultaneous transceivers, each dedicated to specific frequency bands. This parallel architecture achieves the same interference prevention goal without requiring filter reconfiguration

Inventive Principle:

Principle #13The other way round (Inversion)

3Device complexity

If a single transceiver switches between different frequency bands, then device complexity is reduced, but communication latency increases due to reconfiguration time

Engineering Contradiction:

Improvetransceiver configurationVSAvoidband switching latency

Core Design Contradiction:

Device complexityVSLoss of time

Solution Approach 1:

Multiple transceivers operate simultaneously and continuously on their assigned frequency bands without interruption. While transceiver 1 continuously communicates on first and second bands, transceiver 2 continuously communicates on third band, eliminating idle reconfiguration periods and ensuring uninterrupted data flow across all RATs

Inventive Principle:

Principle #20Continuity of useful action

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

Conjugate filters enable simultaneous and interference-free operation of multiple RATs by allowing one RAT to sweep through different bands within a frequency range while maintaining optimal performance for both, thus enhancing data rate and minimizing latency.

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

Methodology Applied

Scientific EffectFilter (electronic): Filter (electronic)

Data Source

PatentUS20260066937A1Wireless Circuitry with Multi-Technology Coexistence

Publication Date: 2026.03.05 APPLE INC

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.