Shared Harmonic Rejection Mixer Layout for Multi-Carrier RF Mixing

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Solution Overview

Problem

The expansion of circuitry in mixer designs due to the need to handle multiple carriers leads to issues with cost, size, power consumption, and signal path considerations, particularly at high frequencies, where traditional approaches result in increased complexity and inefficiency.

Innovation Solution

A mixer arrangement that shares mixer unit cells between harmonic rejection mixers, utilizing a signal generation unit to provide binary control signals for sign switching and current output, ensuring all mixer unit cells remain active and transconductances sum to resemble a sinusoidal waveform, thereby reducing circuitry and layout area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple separate mixers are used to handle multiple carriers, then the ability to process multiple carriers is improved, but the circuitry size and complexity increase

Engineering Contradiction:
Improveability to process multiple carriersVSAvoidcircuitry size
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple harmonic rejection mixers into a single integrated mixer arrangement that processes multiple carriers simultaneously. Multiple carriers are mixed in parallel within the same circuit structure, sharing common components such as the pulse sequence generator and mixer core, thereby reducing overall circuitry size while maintaining the ability to handle multiple carriers

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The mixer arrangement is designed with universal functionality to process multiple carriers through a single unified structure. The same mixer circuitry can handle different carrier frequencies by applying appropriate local oscillator signals, making the device multi-functional rather than requiring separate dedicated mixers for each carrier

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

2Productivity

If multiple separate mixers are used to handle multiple carriers, then the processing capability is improved, but the power consumption increases

Engineering Contradiction:
Improveprocessing capabilityVSAvoidpower consumption
Core Design Contradiction:
ProductivityVSUse of energy by stationary object

Solution Approach 1:

By merging multiple mixer functions into a single integrated arrangement, the patent reduces the total number of active circuit elements required. The shared components and parallel processing architecture allow multiple carriers to be processed while consuming less power than would be required by multiple independent mixer circuits operating separately

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If traditional mixer designs are used, then the signal mixing function is achieved, but the layout area increases

Engineering Contradiction:
Improvesignal mixing functionVSAvoidlayout area
Core Design Contradiction:
Ease of operationVSArea of stationary object

Solution Approach 1:

The mixer arrangement employs a segmented architecture where the mixing function is divided into modular unit cells that can be efficiently arranged in parallel. This segmentation allows for compact layout while maintaining full signal mixing functionality, as each unit cell is optimized for minimal area and can be replicated and combined systematically

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements a nested structure where multiple mixing operations are embedded within a hierarchical circuit architecture. Lower-level mixing unit cells are nested within higher-level signal paths, allowing efficient space utilization and reducing overall layout area while preserving complete signal processing capability

Inventive Principle:
Principle #7Nested doll (Nesting)

4Adaptability or versatility

If more mixer circuitry is added to handle multiple carriers, then the carrier processing ability is improved, but the high-frequency signal path performance deteriorates

Engineering Contradiction:
Improvecarrier processing abilityVSAvoidsignal path performance
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

By consolidating multiple carrier processing functions into a single integrated signal path structure, the patent minimizes the number of discrete signal routing connections required. This merging approach reduces signal path length and the number of high-frequency interconnections, thereby maintaining signal integrity and performance while still enabling multiple carrier processing

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2654202B1Harmonic Rejection Mixer Arrangement
Publication Date: 2020.01.01 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP2654202B1 patent drawingFigure 1
  • EP2654202B1 patent drawingFigure 2
  • EP2654202B1 patent drawingFigure 3

AI summary

It is disclosed a mixer arrangement for complex signal mixing comprising a first harmonic rejection mixer, and a second harmonic rejection mixer. Each of the harmonic rejection mixers comprises at least one mixer unit cell wherein each mixer unit cell comprises a differential input, transconductance elements corresponding to the differential input, and a switching network arranged to switch signals from the transconductance elements to a differential output, and the first and the second harmonic rejection mixers have mutual quadrature phase relationship. The first and the second rejection mixer share a first mixer unit cell comprising an input for receiving a signal to be mixed, an input for receiving control signals derived from a local oscillator signal, and one output for each of the first and second harmonic rejection mixers. A radio circuit comprising such a mixer arrangement and a communication apparatus comprising such a radio circuit are also disclosed.