Wideband low phase-noise signal generation using coaxial resonator in cascaded phase locked loopBlatnik, Aljaž (Avtor) Batagelj, Boštjan (Avtor) PLLphase-noiseDDScoaxial resonatorultra-widebandspur-freeThe 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 applications20242024-05-29 10:48:36Članek v reviji158203sl