Reconfigurable Passive Mixer Cores for Linearity-Power Tradeoffs

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Solution Overview

Problem

Conventional passive mixers in wireless receivers have fixed conversion gain and linearity, leading to unnecessary high power consumption, as they are designed to satisfy worst-case performance requirements across multiple communication standards, while active mixers suffer from higher distortion and noise due to flicker noise.

Innovation Solution

A configurable passive mixer with a controller and clock generator that varies the effective transistor size of multiple passive mixer cores connected in parallel, allowing for adaptive performance adjustments based on communication standards, minimizing power consumption and improving linearity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If passive mixers are designed with fixed conversion gain for worst case receiver configuration, then linearity performance is improved, but power consumption increases unnecessarily for all receiver configurations

Engineering Contradiction:
Improvelinearity performanceVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements dynamic reconfiguration of the passive mixer by dividing it into multiple independently controllable mixer cores. Each core can be selectively enabled or disabled based on the specific communication standard and performance requirements, allowing the mixer to adapt its effective transistor size and conversion gain dynamically rather than being fixed for worst-case scenarios

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the effective transistor size parameter of the passive mixer by selectively enabling different numbers of mixer cores. This parameter change allows the mixer to optimize its conversion gain and linearity performance for different communication standards (TDD, FDD, etc.) without always operating at the worst-case design point, thereby reducing unnecessary power consumption

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If active mixers are used to provide conversion gain greater than 0 dB, then power consumption is reduced, but distortion and noise figure increase due to flicker noise

Engineering Contradiction:
Improvepower consumptionVSAvoiddistortion and noise
Core Design Contradiction:
Use of energy by moving objectVSObject-generated harmful factors

Solution Approach 1:

The patent segments the passive mixer into multiple independent mixer cores that can be selectively activated. This segmentation allows the system to use a passive mixer (which has lower noise and distortion) while still achieving effective gain control by adjusting the number of active cores, avoiding the need to use an active mixer that would introduce flicker noise

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The reconfigurable passive mixer structure provides multi-functionality by being able to adapt to different communication standards and performance requirements. It can achieve variable conversion gain without switching between active and passive mixer types, maintaining the low noise and distortion characteristics of passive mixers across different operating conditions

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

Data Source

PatentEP2342816B1Re-configurable passive mixer for wireless receivers
Publication Date: 2012.11.07 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP2342816B1 patent drawingFigure 1
  • EP2342816B1 patent drawingFigure 2
  • EP2342816B1 patent drawingFigure 3

AI summary

A configurable passive mixer is described herein. According to one exemplary embodiment, the passive mixer comprises a clock generator, a controller, and a plurality of passive mixer cores connected in parallel. The clock generator comprises a local oscillator drive unit for each passive mixer core. The controller varies an effective transistor size of the passive mixer by separately configuringeachof the passive mixercoresto enable/disable each passive mixer core. For example, the controller may selectively enable one or more of the passive mixer cores to vary the effective transistor width of the passive mixer. As the performance requirements and/or the operatingcommunication standard change, the controller may re-configure eachpassive mixer core.