Complex Regenerative Frequency Divider for Low-Noise Wideband Operation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing regenerative frequency dividers suffer from high phase noise, high broadband noise, limited frequency range, and impractical cascading for higher division ratios, leading to reduced signal-to-noise ratio and increased electromagnetic interference.
Innovation Solution
A complex regenerative divider (CRD) using double-quadrature multipliers in a feedback configuration, which performs frequency division by 2 and provides quadrature components, allowing for cascading without additional circuitry and achieving low noise and wide frequency range operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If digital dividers are used, then frequency division is achieved, but phase noise and broadband noise increase
Solution Approach 1:
The patent replaces digital dividers with an analog regenerative divider that uses continuous feedback and oscillation rather than discrete digital switching. This substitution eliminates the sharp transition edges and quantization effects of digital circuits, thereby reducing phase noise and broadband noise while maintaining accurate frequency division through the regenerative feedback mechanism
Solution Approach 2:
The patent implements a regenerative feedback loop where the output of the frequency divider is fed back through a filter and mixer to the input. This positive feedback mechanism creates sustained oscillation at the divided frequency, enabling the circuit to operate as an analog divider with low noise characteristics. The feedback loop continuously reinforces the desired frequency component while suppressing noise through the filtering action
2Object-generated harmful factors
If injection locked dividers are used, then low noise is achieved, but frequency range is limited
Solution Approach 1:
The patent employs a dynamic regenerative feedback system that can adapt to different input frequencies through the natural oscillation characteristics of the feedback loop. Unlike injection-locked dividers that require precise frequency matching, the regenerative divider automatically adjusts its oscillation frequency based on the input signal and feedback conditions, enabling operation across a wide frequency range from low frequencies up to the bandwidth limits of the active devices
Solution Approach 2:
The patent utilizes the frequency-dependent characteristics of the filter and active devices in the feedback loop to enable operation across different frequency ranges. By designing the filter cutoff frequency and active device bandwidth appropriately, the circuit can maintain low noise performance while adapting to various input frequencies, achieving both low noise and wide frequency range operation
3Object-generated harmful factors
If regenerative dividers are used, then low noise performance is achieved, but frequency range is limited by filter cutoff
Solution Approach 1:
The patent transitions from real-frequency operation to complex-frequency operation by using complex signals with both in-phase and quadrature components. This dimensional extension allows the divider to process a wider range of frequencies simultaneously through the complex feedback mechanism, effectively doubling the usable frequency range compared to traditional real-valued regenerative dividers while maintaining low noise performance
Data Source
AI summary
A regenerative frequency divider device including a plurality of multipliers, each of which has a first input port, a second input port and an output port; a first combiner coupled to the plurality of multipliers so as to receive an output signal from at least two of the multipliers; and a second combiner coupled to the plurality of multipliers so as to receive an output signal from at least two of multipliers. Further, a first output signal generated by the first combiner is coupled to the second input port of at least two of the multipliers; and a second output signal generated by the second combiner is coupled to the second input port of at least two of the multipliers such that a complex signal is fed back to the multipliers performing the down conversion process. The present invention divider CRD can achieve superior output noise floor of −180 dBc/Hz at multi-GHz frequencies.