Combined-Output LNA Front-End for Multi-Band RF Interconnect Reduction

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Solution Overview

Problem

Current wireless devices with multiple receivers for different frequency bands and radio technologies require extensive circuitry and interconnections, leading to increased cost and complexity, as LNAs are typically implemented on RFICs with separate interconnections and impedance matching circuits for each frequency band.

Innovation Solution

Implementing LNAs with combined outputs on a front-end module, where the outputs are connected via a single interconnection to receive circuits on an RFIC, reducing the number of interconnections and impedance matching circuits, and sharing receive circuits among multiple LNAs to minimize circuitry and cost.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If LNAs are implemented on RFIC with separate interconnections and impedance matching circuits for each frequency band, then each frequency band can be received independently, but the number of interconnections and circuitry increases

Engineering Contradiction:
Improvefrequency band reception capabilityVSAvoidnumber of interconnections and circuitry
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Multiple LNAs for different frequency bands are merged into a single integrated structure on the front-end module, with their outputs combined and connected to the RFIC through a single interconnection. This consolidates multiple separate circuits into one unified system, reducing the overall number of interconnections and circuit components while maintaining the ability to receive multiple frequency bands.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The front-end module is designed as a universal platform that houses multiple LNAs capable of handling different frequency bands through a single interface to the RFIC. This multi-functional design allows the same physical infrastructure to support multiple frequency reception functions without requiring separate dedicated paths for each band.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If multiple LNAs are implemented with separate interconnections, then each LNA can be optimized for its specific frequency band, but the number of interconnections and cost increase

Engineering Contradiction:
Improvefrequency band optimizationVSAvoidmanufacturing cost and complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

Multiple frequency-optimized LNAs are physically combined on the front-end module with their outputs merged into a single connection point. This allows each LNA to maintain its frequency-specific optimization while sharing common infrastructure, thereby reducing manufacturing complexity and cost compared to implementing separate independent connections for each LNA.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system is segmented into two functional parts: frequency-specific LNA stages on the front-end module and a universal RFIC interface. This segmentation allows optimization at the LNA level for different frequencies while consolidating the interconnection infrastructure at the RFIC interface level, reducing overall manufacturing complexity.

Inventive Principle:
Principle #1Segmentation

3Device complexity

If LNAs are located on the front-end module with combined outputs, then the number of interconnections is reduced, but the receive circuits must handle combined signals from multiple LNAs

Engineering Contradiction:
Improvenumber of interconnectionsVSAvoidsignal combination handling
Core Design Contradiction:
Device complexityVSDifficulty of detecting and measuring

Solution Approach 1:

The outputs of multiple LNAs are merged into a single combined signal path that connects to the RFIC. This merging reduces the number of interconnections required, as multiple separate signal paths are consolidated into one. The receive circuits on the RFIC are designed to handle this combined signal, processing it accordingly.

Inventive Principle:
Principle #5Merging (Combining)

4Device complexity

If receive circuits are shared among multiple LNAs, then circuitry is reduced, but the receive circuits must support multiple frequency bands

Engineering Contradiction:
Improvecircuitry reductionVSAvoidmulti-frequency support capability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The receive circuits on the RFIC are designed as universal, multi-functional components capable of processing signals from multiple frequency bands. This universality allows the same receive circuit infrastructure to handle combined outputs from LNAs tuned to different frequencies, reducing the need for separate receive circuits for each frequency band while maintaining full multi-frequency support capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP2745407B1Low noise amplifiers with combined outputs
Publication Date: 2018.07.04 QUALCOMM INC
  • EP2745407B1 patent drawingFigure 1
  • EP2745407B1 patent drawingFigure 2
  • EP2745407B1 patent drawingFigure 3

AI summary

Multiple low noise amplifiers (LNAs) with combined outputs are disclosed. In an exemplary design, an apparatus includes a front-end module and an integrated circuit (IC). The front-end module includes a plurality of LNAs having outputs that are combined. The IC includes receive circuits coupled to the plurality of LNAs via a single interconnection. In an exemplary design, each of the plurality of LNAs may be enabled or disabled via a respective control signal for that LNA. The front-end module may also include receive filters coupled to the plurality of LNAs and a switchplexer coupled to the receive filters. The front-end module may further include at least one power amplifier, and the IC may further include transmit circuits coupled to the at least one power amplifier.