Multi-Phase Harmonic Local Oscillator for Low-Power RF Mixing

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Solution Overview

Problem

Existing RF-receivers consume a significant amount of power due to the generation of local oscillator (LO) signals for down-conversion, with more than 50% of total power consumption attributed to the local oscillator and its buffers.

Innovation Solution

The apparatus comprises a local oscillator (LO) configured to oscillate at an oscillation frequency and generate a set of LO signals, where each signal has a frequency equal to a multiplication factor m times the oscillation frequency, and is separated by adjacent signals by a phase difference of 360° divided by an integer n, allowing for reduced power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the local oscillator operates at a higher frequency to provide sufficient LO signal strength for down-conversion, then the down-conversion effectiveness is improved, but the power consumption of the local oscillator and its buffers increases

Engineering Contradiction:

Improvedown-conversion effectivenessVSAvoidpower consumption of local oscillator

Core Design Contradiction:

PowerVSUse of energy by moving object

Solution Approach 1:

The patent divides the LO signal generation into multiple frequency components (fundamental frequency and harmonics) and distributes them to different mixer paths. The fundamental frequency LO signal drives one set of mixers while harmonic frequency LO signals drive other mixer paths, allowing each path to operate effectively at its optimal frequency while sharing the total power burden across multiple oscillation sources

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent extends the LO signal generation from a single frequency dimension to multiple frequency dimensions by utilizing both the fundamental frequency and its harmonics. This multi-dimensional approach allows the system to achieve effective down-conversion across multiple mixer paths simultaneously, reducing the power requirement per individual LO source while maintaining overall conversion effectiveness

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Use of energy by moving object

If the local oscillator operates at a lower frequency to reduce power consumption, then the power requirements are reduced, but the down-converted signal strength decreases and requires additional filtering

Engineering Contradiction:

Improvepower consumption of local oscillatorVSAvoiddown-converted signal strength

Core Design Contradiction:

Use of energy by moving objectVSPower

Solution Approach 1:

The patent segments the down-conversion process into multiple parallel paths, each handling a specific frequency component. By distributing the LO signal across fundamental and harmonic frequency paths, each path processes a portion of the total signal energy, maintaining adequate signal strength in each branch while allowing the individual LO sources to operate at lower power levels

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent converts the typically harmful effect of harmonic distortion into a beneficial resource. Instead of filtering out harmonics as unwanted noise, the system intentionally generates and utilizes harmonic frequency LO signals to drive additional mixer paths, thereby converting what would be signal degradation into useful down-conversion capability that reduces overall power consumption

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Use of energy by moving object

If higher harmonics of the LO signal are used for down-conversion to reduce power consumption, then the power consumption of the local oscillator is reduced, but the down-converted signal with the main harmonic becomes significantly stronger than the desired harmonic signal

Engineering Contradiction:

Improvepower consumption of local oscillatorVSAvoidsignal ratio between main harmonic and desired harmonic

Core Design Contradiction:

Use of energy by moving objectVSLoss of information

Solution Approach 1:

The patent segments the LO signal distribution so that different mixer paths receive different frequency components (fundamental and harmonics). This segmentation ensures that each path processes a specific harmonic component, preventing the overwhelming main harmonic from interfering with the desired harmonic extraction in any single path, while maintaining the power consumption benefits of lower frequency operation

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by providing different LO signal characteristics to different mixer paths based on their specific requirements. Each path receives LO signals optimized for its function, with appropriate frequency components and phase relationships, allowing effective extraction of desired harmonic signals while suppressing unwanted components in each local processing domain

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS12323102B2Apparatus comprising a local oscillator for driving a mixer

Publication Date: 2025.06.03 RENESAS DESIGN NETHERLANDS BV

AI summary

An apparatus comprising a local oscillator (LO) for driving a mixer, the LO being configured to oscillate at an oscillation frequency, and generate a first set of LO signals, wherein each of the first set of LO signals has a LO signal frequency equal to a first multiplication factor m multiplied by the oscillation frequency, the first multiplication factor m, being an integer greater than or equal to two, and each of the first set of LO signals is separated by adjacent LO signals by a phase difference equal to 360° divided by a first variable n, the first variable n being an integer that is greater than or equal to two.