A Novel Three-Point Modulation Technique for Fractional-N Frequency Synthesizer Applications
نویسندگان
چکیده
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 ~ 2.6 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 μs 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 μs, respectively.
منابع مشابه
Quantization Noise Cancellation of Fractional-N Frequency Synthesizers Using Pre-distortion Technique
This work proposes a novel pre-distortion technique for the quantization noise cancellation of fractional-N frequency synthesizers. The proposed technique utilizes the coordinate rotation digital computer (CORDIC) algorithm to pre-distort the baseband signal of a wireless system with the quantization noise. The pre-distorted signal then modulates the noisy output signal of the fractional-N freq...
متن کاملPhase Noise Improvement in Fractional-N Synthesizer with 90" Phase Shift Lock
An effective technique for phase noise improvement in a fractional-N synthesizer is described. The method requires using in a 90" phase shift lock a non-linear continuous-time or sampled-data block before the loop filter. Behavioral simulations on a fractional-N synthesizer incorporating different non-linear blocks and a second-order single bit sigma delta modulator show that it is possible to ...
متن کاملA 2.4-GHz ISM Band Delta-Sigma Fractional-N Frequency Synthesizer with Automatic Calibration Technique
In the paper, a programmable phase-locked loop (PLL) based ISM band fractional-N frequency synthesizer, commonly used in wireless communication system, is presented. The third order error-feedback Delta-Sigma modulator and high linearity offset phase frequency detector (PFD)/ Charge Pump (CP) are adopted to reduce close-in phase noise due to ∆Σ quantization noise folding. Automatic calibration ...
متن کاملDigital High Order Multiplier-free Delta Sigma Modulator for Multistandard Fractional-N Frequency Synthesizer
This paper proposes a new stable design strategy for 1bit high order digital ∆Σ modulator for multistandard fractionalN frequency synthesizer. The proposed digital ∆Σ modulator presents simplicity, low power consumption and controls a dualmodulus divider instead of multi-modulus one as in existing ∆Σ fractional-N frequency synthesizer. Simulation results illustrate the ∆Σ modulator good perform...
متن کاملInvestigation of Mechanisms for Spur Generation in Fractional-N Frequency Synthesizers
With the advances in wireless communication technology over last two decades, the use of fractional-N frequency synthesizers has increased widely in modern wireless communication applications due to their high frequency resolution and fast settling time. The performance of a fractional-N frequency synthesizer is degraded due to the presence of unwanted spurious tones (spurs) in the output spect...
متن کامل