Dual-Mode RF Oscillator Using One Resonator for Wide Tuning

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Solution Overview

Problem

Radio frequency oscillators face challenges in achieving a high tuning range without increasing noise floor or size, particularly when implemented as RFICs on semiconductor substrates, as existing solutions often require separate resonator circuits or mode switching, leading to power consumption and area penalties.

Innovation Solution

A radio frequency oscillator design that utilizes a single resonator circuit resonant in both differential and common modes, employing a transformer with a 1:2 turns ratio and a Colpitts oscillator configuration, allowing for tunable resonance frequencies and efficient tuning range expansion without area penalties or degradation in differential mode performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If separate resonator circuits are employed to increase tuning range, then the tuning range is improved, but the die area and power consumption increase

Engineering Contradiction:
Improvetuning rangeVSAvoiddie area
Core Design Contradiction:
Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

A single resonator circuit is designed to support both differential mode and common mode oscillations, enabling it to function across multiple frequency bands (2.4-5.3 GHz) without requiring separate resonator circuits. This multi-functional approach allows the same physical structure to serve dual purposes, achieving wide tuning range while minimizing die area occupation

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

2Adaptability or versatility

If separate resonator circuits are employed to increase tuning range, then the tuning range is improved, but the power consumption increases

Engineering Contradiction:
Improvetuning rangeVSAvoidpower consumption
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The resonator circuit is designed to be universally applicable for both differential and common mode operations, eliminating the need for multiple separate resonator circuits. This reduces the overall power consumption by avoiding the power requirements of additional circuit components while maintaining the ability to operate across the full 2.4-5.3 GHz tuning range

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

3Adaptability or versatility

If mode switching is used to expand tuning range, then the tuning range is improved, but the LC resonator circuit size increases

Engineering Contradiction:
Improvetuning rangeVSAvoidLC resonator circuit size
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The resonator circuit employs dynamic mode switching between differential and common mode oscillations to achieve frequency tuning. By dynamically changing the oscillation mode rather than physically reconfiguring the circuit structure, the patent achieves wide tuning range (2.4-5.3 GHz) while maintaining a compact LC resonator circuit size suitable for integrated implementation

Inventive Principle:
Principle #15Dynamics

4Adaptability or versatility

If high-order LC resonator circuits are used for mode switching, then the tuning range is improved, but the noise floor increases

Engineering Contradiction:
Improvetuning rangeVSAvoidnoise floor
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent uses dynamic switching between differential and common mode oscillations in a carefully designed resonator circuit rather than relying on high-order LC resonators. This dynamic approach allows for clean mode transitions with proper isolation, achieving wide tuning range while maintaining low noise floor performance suitable for RFIC applications

Inventive Principle:
Principle #15Dynamics

5Area of stationary object

If a single resonator circuit is used for both differential and common mode, then the area is reduced, but the coupling factor must be precisely controlled

Engineering Contradiction:
Improvedie areaVSAvoidcoupling factor control
Core Design Contradiction:
Area of stationary objectVSManufacturing precision

Solution Approach 1:

The resonator circuit is designed with specific local structural characteristics that create different magnetic coupling factors for differential and common mode oscillations. By optimizing the local geometry and configuration of the resonator elements, the patent achieves the required coupling factor differentiation (higher for differential mode, lower for common mode) through precise structural design rather than relying solely on component tolerances

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution provides a compact, efficient radio frequency oscillator with a high tuning range, maintaining low size and phase noise performance, suitable for implementation as RFICs, by leveraging the difference in magnetic coupling factors between differential and common modes.

Implementation Method 1

the transformer (201) comprises a primary winding (203) and a secondary winding (205), the primary winding (203) being inductively coupled with the secondary winding (205)

Methodology Applied
Scientific EffectInductive coupling: Electromagnetic Induction

Implementation Method 2

the resonator circuit (101) is resonant at an excitation of the resonator circuit (101) in a differential mode and at an excitation of the resonator circuit (101) in a common mode

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP3158640B1A radio frequency oscillator
Publication Date: 2021.04.07 HUAWEI TECH CO LTD
  • EP3158640B1 patent drawingFigure 1
  • EP3158640B1 patent drawingFigure 2
  • EP3158640B1 patent drawingFigure 3

AI summary

The invention relates to a radio frequency oscillator (100), the radio frequency oscillator (100) comprising a resonator circuit (101) being resonant at an excitation of the resonator circuit (101) in a differential mode and at an excitation of the resonator circuit (101) in a common mode, wherein the resonator circuit (101) has a differential mode resonance frequency at the excitation in the differential mode, and wherein the resonator circuit (101) has a common mode resonance frequency at the excitation in the common mode, a first excitation circuit (103) being configured to excite the resonator circuit (101) in the differential mode to obtain a differential mode oscillator signal oscillating at the differential mode resonance frequency, and a second excitation circuit (105) being configured to excite the resonator circuit (101) in the common mode to obtain a common mode oscillator signal oscillating at the common mode resonance frequency.