Microwave Frequency Synthesizer With Balanced Delay Drift Canceling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing frequency synthesizers are unsuitable for applications requiring signal modulation and phase coherent frequency switching, particularly in the microwave region, due to high phase noise and inadequate long-term phase stability across multiple channels.
Innovation Solution
A frequency synthesizer with a drift canceling loop and a linear signal path, featuring a balanced delay configuration with a fixed and adjustable complementary delay, enabling low phase noise and rapid phase coherent frequency switching, suitable for microwave operations and applications like radar signal simulation and direction finding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a drift canceling loop is used to reduce phase noise, then phase noise is reduced, but the delay balance is difficult to maintain across frequency ranges
Solution Approach 1:
The patent implements a dynamically adjustable delay line that can be tuned to compensate for group delay variations across different frequency ranges. This dynamic adjustment mechanism allows the system to maintain optimal delay balance adaptively, resolving the contradiction between reducing phase noise through drift canceling loops and maintaining delay balance across frequencies.
2Object-affected harmful factors
If a high stability oscillator is used to achieve low phase noise, then phase noise is reduced, but frequency switching time increases
Solution Approach 1:
The patent segments the frequency synthesis function into multiple oscillators operating at different frequency ranges, each with its own drift canceling loop. This segmentation allows rapid switching between frequency ranges while maintaining low phase noise within each range, resolving the contradiction between phase noise reduction and frequency switching speed.
Solution Approach 2:
The system pre-configures multiple oscillators with their respective drift canceling loops ready to operate. When frequency switching is required, the system can immediately activate the pre-configured oscillator for the target frequency range, eliminating warm-up time and achieving rapid frequency switching while maintaining low phase noise performance.
3Stability of the object's composition
If multiple frequency synthesizers are coordinated for long term phase stability, then phase stability is improved, but system complexity increases
Solution Approach 1:
The patent merges multiple frequency synthesizers into a coordinated system where each synthesizer operates with its own drift canceling loop but shares common calibration procedures and control mechanisms. This merging approach maintains long-term phase stability across channels while reducing coordination complexity through standardized interfaces and unified calibration protocols.
Data Source
AI summary
An example frequency converter includes a drift canceling loop with a balanced delay and a linear signal path (e.g., linear with respect to frequency scaling, amplitude modulation, and/or phase modulation). One side of the drift canceling loop includes a fixed delay, and the opposite side includes an adjustable, complementary delay. The adjustable, complementary delay facilitates precision matching of the signal delays on each side of the loop over a range of frequencies, which results in a significant improvement in noise cancelation, particularly at large offsets to the carrier, while permitting the use of a higher noise, but very fast tuning course scale oscillator. The linear signal path from the signal generator to an RF output facilitates modulation of the signal by the signal generator. A modular format is an advantageous embodiment of the invention that includes the removal of the frequency synthesizer's low phase noise reference into a separate module.