Design of Down Scalers in Mixed-Signal GHz Frequency Synthesizer

An optimized method is presented to design the down scalers in a GHz frequency synthesizer. The down scalers are comprised of dual modulus prescaler （DMP） and programmable ＆ pulse swallow divider,different methods of high frequency analog circuit and digital logical synthesis are adopted respectively. Using a DMP high speed, lower jitter and lower power dissipation are obtained,and output frequency of 133.0MHz of the DMP working at divide-by-8 shows an RMS jitter less than 2ps. The flexibility and reusability of the progrs, mmable divider is high;its use could be extended to many complicated frequency synthesizers. By comparison,it is a better design on performance of high-frequency circuit and good design flexibility.

Low Jitter,Dual-Modulus Prescalers for RF Receivers

Dual-modulus prescalers （DMP） for RF receivers are studied. An improved D-latch is proposed to increase the speed and the driving capability of the DMP. A novel D-latch architecture integrated with ‘OR＇ logic is proposed to decrease the complexity of the circuit. A divided-by-16/17 DMP for application in a digital video broadcasting-terrestrial receiver is realized with a TSMC 0.18μm mixed-signal CMOS process. The programmable ＆ pulse swallow divider in this receiver is designed with a 0.18μm CMOS standard cell library and realized in the same process. The measured results show that the DMP has an output jitter of less than 0.03% and works well with the programmable ＆ pulse swallow divider.

Frequency synthesizer for DRM/DAB/AM/FM RF front-end

This paper describes a wideband low phase noise frequency synthesizer.It operates in the multi-band including digital radio mondiale DRM digital audio broadcasting DAB amplitude modulation AM and frequency modulation FM .In order to cover the signals of the overall frequencies a novel frequency planning and a new structure are proposed. A wide-band low-phase-noise low-power voltage-control oscillator VCO and a high speed wide band high frequency division ratio pulse swallow frequency divider with a low power consumption are presented.The monolithic DRM/DAB/AM/FM frequency synthesizer chip is also fabricated in a SMIC＇s 0.18-μm CMOS process.The die area is 1 425 μm ×795 μm including the test buffer and pads. The measured results show that the VCO operating frequency range is from 2.22 to 3.57 GHz the measured phase noise of the VCO is 120.22 dBc/Hz at 1 MHz offset the pulse swallow frequency divider operation frequency is from 0.9 to 3.4 GHz.The phase noise in the phase-locked loop PLL is-59.52 dBc/Hz at 10 kHz offset and fits for the demand of the DRM/DAB/AM/FM RF front-end. The proposed frequency synthesizer consumes 47 mW including test buffer under a 1.8 V supply.

A 37 GHz wide-band programmable divide-by-N frequency divider for millimeter-wave silicon-based phase-locked loop frequency synthesizers

A 37 GHz wide-band programmable divide-by-N frequency divider(FD) composed of a divide-by-2 divider(acting as the first stage) and a divider with a division ratio range of 273–330(acting as the second stage) has been designed and fabricated using standard 90 nm CMOS technology. The second stage divider consists of a high-speed divide-by-8/9 dual-modulus prescaler, a pulse counter, and a swallow counter. Both the first stage divider(with high speed) and the divide-by-8/9 prescaler employ dynamic current-mode logic(DCML) structure to improve the operating performance. The first stage divider can work from 2 to 40 GHz and the whole divider covers a wide frequency range from 25 to 37 GHz. The input sensitivity is as low as-20 d Bm at 32 GHz and the phase noise at 37 GHz is less than-130 d Bc/Hz at an offset of 1 MHz. The whole chip dissipates 17.88 m W at a supply voltage of 1.2 V and occupies an area of only 730 μm×475 μm.