Terahertz Injection-Locked Radiator Phase Noise

Solution Overview

Problem

Current terahertz circuit implementations face challenges in achieving sufficient output power and low phase noise due to inadequate cut-off frequency and breakdown voltage, leading to inefficient DC-to-RF conversion and high power consumption, particularly in CMOS-based systems.

Innovation Solution

The implementation of an injection-locked terahertz radiator system comprising a voltage-controlled oscillator (VCO) with intrinsic-delay compensation and harmonic boosting techniques, along with injection-locked frequency multipliers, to optimize phase noise and output power, enabling efficient terahertz radiation in a compact, low-cost CMOS-based solution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If existing CMOS-based terahertz circuit implementations are used, then device integration and cost are improved, but DC-to-RF conversion efficiency deteriorates and output power is insufficient

Engineering Contradiction:

Improvedevice integrationVSAvoidDC-to-RF conversion efficiency

Core Design Contradiction:

Ease of manufactureVSUse of energy by moving object

Solution Approach 1:

The system segments the frequency multiplication function into multiple injection-locked frequency multipliers operating in parallel. Each multiplier handles a specific harmonic generation task, allowing optimized design for each function while maintaining overall system integration in CMOS technology.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system employs dynamic frequency multiplication through injection-locked oscillators that can be tuned to different operating frequencies. The VCO generates a fundamental frequency that is dynamically multiplied by integer factors (N=2,3,4) through the frequency multipliers, enabling adaptive frequency synthesis for terahertz generation.

Inventive Principle:

Principle #15Dynamics

2Ease of manufacture

If existing CMOS-based terahertz circuit implementations are used, then device integration and cost are improved, but output power deteriorates

Engineering Contradiction:

Improvedevice integrationVSAvoidoutput power

Core Design Contradiction:

Ease of manufactureVSPower

Solution Approach 1:

The system merges multiple frequency-multiplied signals from parallel injection-locked frequency multipliers and combines them constructively at the antenna array. This signal combining approach achieves higher output power by aggregating the power contribution from multiple synchronized oscillators operating at the same frequency.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The system employs dynamic frequency multiplication through injection-locked oscillators that can be tuned to different operating frequencies. The VCO generates a fundamental frequency that is dynamically multiplied by integer factors (N=2,3,4) through the frequency multipliers, enabling adaptive frequency synthesis for terahertz generation.

Inventive Principle:

Principle #15Dynamics

3Ease of manufacture

If existing CMOS-based terahertz circuit implementations are used, then device integration and cost are improved, but phase noise deteriorates

Engineering Contradiction:

Improvedevice integrationVSAvoidphase noise

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The system introduces a phase noise filtering mechanism where the injection-locked frequency multipliers act as intermediaries. The injection locking process inherently filters phase noise by locking the output phase to the reference input, while the parallel architecture and signal combining further suppress phase noise through coherent addition of multiple low-phase-noise signals.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system employs dynamic frequency multiplication through injection-locked oscillators that can be tuned to different operating frequencies. The VCO generates a fundamental frequency that is dynamically multiplied by integer factors (N=2,3,4) through the frequency multipliers, enabling adaptive frequency synthesis for terahertz generation.

Inventive Principle:

Principle #15Dynamics

4Speed

If high-order harmonics are used for frequency generation above 300 GHz, then terahertz frequency generation is achieved, but power efficiency deteriorates

Engineering Contradiction:

Improvefrequency generation capabilityVSAvoidpower efficiency

Core Design Contradiction:

SpeedVSUse of energy by moving object

Solution Approach 1:

The system segments the frequency multiplication function into multiple injection-locked frequency multipliers operating in parallel. Each multiplier handles a specific harmonic generation task, allowing optimized design for each function while maintaining overall system integration in CMOS technology.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system changes the operating parameters of the frequency multipliers to optimize harmonic generation efficiency. By adjusting the injection ratio, loading conditions, and transistor biasing in the injection-locked oscillators, the system enhances the conversion efficiency from fundamental frequency to high-order harmonics, achieving better power efficiency at terahertz frequencies.

Inventive Principle:

Principle #35Parameter changes

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

This approach results in improved phase noise and DC-to-RF efficiency, achieving output frequencies up to 315.5 GHz with a phase noise of −109.3 dBc/Hz at 10-MHz offset and 0.42% efficiency, suitable for applications like imaging, spectroscopy, and high-speed wireless communication.

Implementation Method 1

a voltage controlled oscillator (VCO) providing multiple-phase output

Methodology Applied

Scientific EffectOscillation: Harmonic Oscillator

Implementation Method 2

injection-locked frequency multipliers (e.g., injection-locked frequency quadruplers (ILFQs))

Methodology Applied

Scientific EffectInjection locking:

Implementation Method 3

antenna elements of an antenna array... for radiating signals in the terahertz frequency range

Methodology Applied

Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Data Source

PatentUS9923599B1Terahertz injection-locked radiator

Publication Date: 2018.03.20 CITY UNIVERSITY OF HONG KONG

AI summary

Systems and methods which provide injection-locked circuit configurations for radiating signals in the terahertz frequency range with improved phase noise and signal output power are described. Embodiments of the invention provide an injection-locked terahertz radiator system comprising a half-quadrature voltage controlled oscillator (HQVCO), a plurality of injection-locked frequency quadruplers (ILFQs), and antenna elements. In operation according to embodiments, injection-locking provided by the ILFQs may be utilized to facilitate individual optimization of the output power and the phase noise. Intrinsic-delay compensation and harmonic boosting techniques may be utilized in configurations of the foregoing injection-locked terahertz radiator system to optimize the phase noise of the HQVCO and the output power of the ILFQs, respectively. Embodiments of an injection-locked terahertz radiator system herein are implemented as a fully integrated solution with compact form factor, providing high reliability and low cost.