Single-VCO UWB Synthesizer With Parallel Divider Branches
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Solution Overview
Problem
Conventional frequency synthesizers for ultra-wideband (UWB) applications require multiple voltage-controlled oscillators (VCOs), leading to complex designs, large chip sizes, and high costs, while using a single VCO with a large tuning range compromises phase noise performance and startup conditions.
Innovation Solution
A frequency synthesizer architecture utilizing a single high-frequency VCO with a limited tuning range, coupled with a divider bank featuring multiple parallel divider branches, provides a continuous spectrum with at least 64% frequency coverage, allowing generation of multiple UWB frequencies without the need for multiple VCOs or a wide-tuning-range VCO.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple VCOs are used to target different UWB frequencies, then frequency coverage is improved, but device complexity and chip size increase
Solution Approach 1:
The patent combines multiple VCO functions into a single VCO by integrating it with a divider bank system. The single VCO operates at a fixed frequency while the divider bank provides multiple division ratios to generate different UWB frequencies, thereby achieving wide frequency coverage without requiring multiple separate VCO circuits.
Solution Approach 2:
The single VCO is designed to work universally across all UWB channels when combined with the divider bank. The VCO serves multiple functions by providing a stable reference frequency that, when divided by different ratios, covers the entire UWB spectrum, making the system adaptable to various frequency requirements.
2Adaptability or versatility
If a single VCO with large tuning range is used to cover wide spectrum, then frequency coverage is improved, but phase noise performance and startup conditions deteriorate
Solution Approach 1:
The frequency generation function is segmented between the VCO and the divider bank. The VCO is responsible for generating a single stable high-frequency signal, while the frequency multiplication and spectrum expansion functions are segmented to the divider bank, which provides multiple division ratios to achieve wide frequency coverage without compromising VCO performance.
Solution Approach 2:
The divider bank acts as an intermediary between the single VCO and the output frequencies. Instead of requiring the VCO to directly generate all UWB frequencies with a large tuning range, the divider bank mediates by dividing the VCO's fixed frequency by different ratios, thereby achieving wide frequency coverage while maintaining the VCO's optimal phase noise performance.
3Adaptability or versatility
If multiple VCOs are used to target different UWB frequencies, then frequency coverage is improved, but chip size and cost increase
Solution Approach 1:
The patent merges multiple VCO circuits into a single VCO integrated with a divider bank. This consolidation reduces the total chip area by eliminating redundant VCO structures while maintaining the capability to generate all required UWB frequencies through the divider bank's multiple division ratios.
Data Source
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AI summary
The present disclosure relates to a frequency synthesizer capable of generating a full spectrum for ultra-wideband applications by utilizing a single voltage-controlled oscillator (VCO). The disclosed frequency synthesizer includes a phase-frequency detector (PFD), a charge pump (CP), a VCO, a feedback divider, and a divider bank. The PFD, the CP, the VCO, and the feedback divider are coupled in series in a closed loop, while the divider bank follows the VCO and is not included in the closed loop. Herein, the VCO has a tuning range less than 35%. The divider bank includes two or more divider branches parallel to each other, each of which is configured to provide a different division ratio. An oscillating spectrum of the VCO and division ratios of the two or more divider branches are selected such that the divider bank is capable of providing a continuous spectrum with at least a 64% frequency coverage.