NLTL Harmonic Phase Standard for Stable Broadband Phase Measurement
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Solution Overview
Problem
Conventional harmonic phase standards face limitations in accurately determining the phase of nonlinear components in telecom networks due to phase stability issues, limited harmonic content, and frequency scalability challenges.
Innovation Solution
A harmonic phase standard utilizing a nonlinear transmission line (NLTL) with a logic gate, amplifier, and varactor diodes on a gallium arsenide substrate, which generates high-frequency content by sharpening waveform edges and adding harmonic content, along with a pulse-forming network and power splitters for scalable frequency measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a Schottky diode is used as a harmonic phase standard, then the device structure is simple, but the harmonic content is limited
Solution Approach 1:
The patent transforms the Schottky diode from its conventional role as a detector into an active nonlinear element by applying reverse bias voltage. This parameter change enables the diode to generate rich harmonic content through its nonlinear capacitance and resistance characteristics, resolving the contradiction between simple structure and limited harmonic content.
2Quantity of substance
If a step-recovery diode is used as a harmonic phase standard, then the harmonic content is enhanced, but phase stability deteriorates
Solution Approach 1:
The patent introduces a pulse generator as an intermediary component that provides precisely timed triggering signals to the Schottky diode. This mediator ensures consistent phase relationships across multiple measurement cycles, resolving the phase stability issue while maintaining the harmonic content enhancement provided by the diode's nonlinear characteristics.
Solution Approach 2:
The system employs periodic pulse triggering at the fundamental frequency to drive the Schottky diode's nonlinear response. This periodic action ensures that harmonics are generated at consistent phase intervals, improving phase stability while maintaining rich harmonic content for measurement.
3Reliability
If an InP-based device is used as a harmonic phase standard, then phase stability is improved, but frequency scalability is limited due to circuit complexity
Solution Approach 1:
The patent designs the Schottky diode-based harmonic phase standard to serve multiple frequency ranges and measurement applications through a unified architecture. The diode's nonlinear characteristics naturally provide harmonic generation across broad frequency ranges, eliminating the need for frequency-specific circuit designs and enabling scalable measurements from low to high frequencies.
4Ease of operation
If conventional VNA calibration is used for nonlinear measurements, then the measurement process is simple, but phase measurement accuracy deteriorates due to different phase lengths at different frequencies
Solution Approach 1:
The patent replaces the conventional VNA's electrical calibration system with a physics-based nonlinear harmonic generation mechanism. By using the Schottky diode's inherent nonlinear characteristics to generate harmonics with known phase relationships, the system eliminates the need for complex multi-frequency electrical calibration procedures while achieving accurate phase measurements.
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 NLTL-based harmonic phase standard provides high phase stability and scalable frequency content, enabling accurate phase measurement and characterization of nonlinear components in telecom networks, addressing previous limitations in phase stability and frequency scalability.
Implementation Method 1
The NLTL receives the amplified waveform from the amplifier and is biased to shape the amplified waveform so as to add harmonic content to the amplified waveform
Implementation Method 2
The logic gate receives the RF signal, buffers it in an amplitude-insensitive manner, and outputs a waveform having modestly sharpened edges relative to the RF signal
Implementation Method 3
The amplifier amplifies the waveform output by the logic gate
Data Source
AI summary
A harmonic phase standard includes an input connectable with a radio frequency (RF) signal source for receiving an RF signal, an output, a signal path extending between the input and the output for propagating the RF signal from the input to the output, and a logic gate, an amplifier and a nonlinear transmission line (NLTL) arranged along the signal path. The logic gate receives the RF signal and outputs a waveform having sharpened edges relative to the RF signal. The amplifier amplifies the waveform output by the logic gate. The NLTL receives the amplified waveform from the amplifier and is biased to shape the amplified waveform so as to add harmonic content to the amplified waveform.