%0 Journal Article %T A Novel Three-Point Modulation Technique for Fractional-N Frequency Synthesizer Applications %A Kang-Chun Peng %A Chiu-Chin Lin %A Ching-Hui Chao %J Radioengineering %D 2013 %I Spolecnost pro radioelektronicke inzenyrstvi %X This paper presents a novel three-point modulation technique for fractional-N frequency synthesizer applications. Convention modulated fractional-N frequency synthesizers suffer from quantization noise, which degrades not only the phase noise performance but also the modulation quality. To solve this problem, this work proposes a three-point modulation technique, which not only cancels the quantization noise, but also markedly boosts the channel switching speed. Measurements reveal that the implemented 2.4 GHz fractional-N frequency synthesizer using three-point modulation can achieve a 2.5 Mbps GFSK data rate with an FSK error rate of only 1.4 %. The phase noise is approximately -98 dBc/Hz at a frequency offset of 100 kHz. The channel switching time is only 1.1 ¦Ěs with a frequency step of 80 MHz. Comparing with conventional two-point modulation, the proposed three-point modulation greatly improves the FSK error rate, phase noise and channel switching time by about 10 %, 30 dB and 126 ¦Ěs, respectively. %K Fractional-N frequency synthesizer %K delta-sigma %K three-point modulation %K phase-locked loop %K GFSK %U www.radioeng.cz/fulltexts/2013/13_01_0269_0275.pdf