Wideband low phase-noise signal generation using coaxial resonator in cascaded phase locked loop

Blatnik, Aljaž (author), Batagelj, Boštjan (author)

The generation of high-quality wideband frequency sweeps presents a significant challenge, particularly in modern telecommunication, radar, and measurement systems where miniaturization is paramount. While phase-locked loops (PLLs) have become the dominant technique for signal generation, their application in broadband sweeps necessitates fractional-N operation. This, in turn, degrades phase noise and introduces unwanted spurs. This paper proposes a novel approach for broadband signal generation. By cascading two PLLs and utilizing a coaxial resonator, we achieve a high-performance oscillator that operates without the excessive fractional spurs, maintaining their level below 80 dBc across the entire frequency band. The prototype demonstrates non-degraded phase noise performance, reaching 102 dBc/Hz at 100 kHz offset and 121 dBc/Hz at 1 MHz offset for signals at 10 GHz. Despite significant frequency jumps, our design achieves lock times below 41 ▫$\mu▫$s. These results, supported by theoretical analysis, validate the proposed methods effectiveness in generating low-noise broadband frequency sweeps, ideal for local oscillator applications

• Language: English
• Keywords: PLL, phase-noise, DDS, coaxial resonator, ultra-wideband, spur-free
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FE - Faculty of Electrical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2024
• Number of pages: 16 str.
• Numbering: Vol. 13, iss. 10, [article no.] 1934
• PID: 20.500.12556/RUL-158203
• UDC: 621.39
• ISSN on article: 2079-9292
• DOI: 10.3390/electronics13101934
• COBISS.SI-ID: 196609283
• Publication date in RUL: 29.05.2024

Record is a part of a journal

• Title: Electronics
• Shortened title: Electronics
• Publisher: MDPI
• ISSN: 2079-9292
• COBISS.SI-ID: 523068953

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: fazno-sklenjena zanka, fazni šum, DDS, koaksialni resonator, ultra-širokopasovno