PLL Frequency Source Using YIG SNE for Phase Noise Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Low cost, compact frequency synthesizers often have inferior phase noise performance, making them unsuitable for certain applications, particularly in military and commercial systems where improved phase noise is required.
Innovation Solution
A frequency source system incorporating a phase-locked loop and a signal-to-noise enhancer (SNE) with a thin film of yttrium iron garnet (YIG) on a gadolinium gallium garnet (GGG) substrate, which acts as a nonlinear passive device to attenuate low-power signals while transmitting high-power signals with minimal loss, thereby suppressing phase noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a low cost, compact frequency synthesizer is used, then the device size and cost are reduced, but the phase noise performance deteriorates
Solution Approach 1:
A signal-to-noise enhancer (SNE) is introduced as an intermediary component between the frequency synthesizer and the output. The SNE uses a magnetic component (yttrium iron garnet film) that selectively attenuates low-power noise signals while allowing high-power desired signals to pass through with minimal loss, thereby improving phase noise performance without sacrificing the compactness or low-cost advantages of the original synthesizer
Solution Approach 2:
The system changes the power level parameter of the signal passing through the frequency synthesizer by using an amplifier to boost the signal power before it enters the SNE. This ensures the signal exceeds the threshold power level, causing the SNE to provide minimal attenuation to the desired signal while still attenuating noise components
2Object-generated harmful factors
If a signal to noise enhancer is added to improve phase noise, then phase noise performance is improved, but the device complexity increases
Solution Approach 1:
The SNE serves as a dedicated intermediary component that handles noise suppression independently, allowing the main frequency synthesizer to remain simple while the noise reduction function is offloaded to a specialized subsystem with passive magnetic materials and basic amplification
Solution Approach 2:
The signal-to-noise enhancer operates autonomously based on the power level of the input signal. When the signal power exceeds the threshold, the SNE automatically provides minimal attenuation; when power is below threshold, it automatically provides high attenuation. This self-adjusting behavior eliminates the need for complex control circuits or calibration procedures
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 system significantly improves phase noise performance by providing high attenuation for low-power signals and low attenuation for high-power signals, resulting in a substantial reduction of phase noise and improved frequency agility without the need for calibration or additional control, suitable for use in phased array systems and stringent commercial applications.
Implementation Method 1
a magnetic component capable of supporting magnetostatic waves; the magnetic component secured in proximity to the microwave transmission line
Implementation Method 2
a thin film of yttrium iron garnet (YIG) epitaxially grown on a gadolinium gallium garnet (GGG) substrate... one or more magnets secured in proximity to the magnetic component... produce, in the magnetic component, a biasing magnetic field
Data Source
AI summary
A frequency source with improved phase noise. In one embodiment a phase-locked loop is used as a component of a frequency source and a signal to noise enhancer (SNE) is used to suppress phase noise produced by the phase-locked loop. The signal to noise enhancer is a nonlinear passive device that attenuates low-power signals while transmitting high power signals with little loss. The signal to noise enhancer may be fabricated as a thin film of yttrium iron garnet (YIG) epitaxially grown on a gadolinium gallium garnet (GGG) substrate, the GGG substrate being secured to a microwave transmission line from the input to the output of the signal to noise enhancer, such that the thin film of yttrium iron garnet is close to the transmission line.