Shared PLL and DTC Frequency Generation for Multi-Radio RF Paths

Solution Overview

Problem

Current multi-radio devices face challenges in miniaturization and power efficiency due to the need for multiple oscillators and synthesizers, which also suffer from frequency pulling issues that degrade modulation quality and spectral performance, especially in MIMO transmitters.

Innovation Solution

A central frequency synthesizer architecture using a single phase-locked loop (PLL) and digital-to-time converters (DTCs) to generate multiple frequencies efficiently, reducing phase noise and decoupling power amplifiers from local oscillators, thereby minimizing circuit real estate and preventing frequency pulling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple oscillators and synthesizers are used for multi-radio devices, then multiple frequency signals can be generated, but device size and power consumption increase

Engineering Contradiction:

Improvemulti-frequency signal generation capabilityVSAvoidcircuit real estate

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent combines multiple oscillators and synthesizers into a single shared local oscillator that serves multiple radio frequency (RF) paths. This consolidation allows multiple frequency signals to be generated through a unified architecture, reducing the overall circuit area while maintaining the capability to support multiple frequency bands and carrier aggregation

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The shared local oscillator is designed to perform multiple functions by generating frequencies for different RF paths through digital control. A single oscillator core can produce multiple output frequencies by adjusting its operation based on control signals, enabling one component to replace what would traditionally require multiple dedicated oscillators

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If multiple oscillators and synthesizers are used for multi-radio devices, then multiple frequency signals can be generated, but power consumption increases

Engineering Contradiction:

Improvemulti-frequency signal generation capabilityVSAvoidpower consumption

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by stationary object

Solution Approach 1:

The patent combines multiple oscillators and synthesizers into a single shared local oscillator that serves multiple radio frequency (RF) paths. This consolidation allows multiple frequency signals to be generated through a unified architecture, reducing the overall circuit area while maintaining the capability to support multiple frequency bands and carrier aggregation

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The shared local oscillator is designed to perform multiple functions by generating frequencies for different RF paths through digital control. A single oscillator core can produce multiple output frequencies by adjusting its operation based on control signals, enabling one component to replace what would traditionally require multiple dedicated oscillators

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Area of stationary object

If power amplifiers are closely coupled with local oscillators, then compact design is achieved, but frequency pulling occurs that degrades modulation quality

Engineering Contradiction:

Improvecircuit real estateVSAvoidmodulation quality and spectral performance

Core Design Contradiction:

Area of stationary objectVSReliability

Solution Approach 1:

The patent introduces a buffer amplifier as an intermediary component between the local oscillator and power amplifiers. This buffer stage acts as a隔离 barrier that prevents the high-power signals from the power amplifiers from coupling back into the local oscillator, thereby eliminating frequency pulling effects while allowing the components to remain in a compact arrangement

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent extracts the local oscillator from the high-power RF path by placing it in a separate, low-power domain. The buffer amplifier serves as the extraction point, allowing the oscillator to be physically close to the power amplifiers for compactness while electrically isolating it from the high-power environment that causes frequency pulling

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentUS10230520B2Direct digital frequency generation using time and amplitude

Publication Date: 2019.03.12 INTEL CORP

AI summary

This application discusses, among other things, apparatus and methods for sharing a local oscillator between multiple wireless devices. In certain examples, an apparatus can include a central frequency synthesizer configured to provide a central oscillator signal having a first frequency, a first transmitter, the first transmitter including a first transmit digital-to-time converter (DTC) configured to receive the central oscillator signal and to provide a first transmitter signal having a second frequency, and a first receiver, the first receiver including a first receive DTC configured to receive the central oscillator signal and to provide a first receiver signal having a first receive frequency.