A wide-range VCO with optimum temperature adaptive tuning

Abstract

-This paper presents an integrated wide-range VCO with a modified tuning scheme to deal with VCO frequency drift over temperature. In this approach, during the coarse-tune operation, VCO tune voltage is a function of temperature such that it resembles the inverse function of VCO fine-tune characteristic. Without degrading VCO performance, the proposed temperature adaptive tuning optimizes the maximum tolerable VCO temperature frequency drift over which PLL remains locked. As a result, VCO gain can be reduced significantly, making VCO less sensitive to PLL tune voltage noise. Integrated in a multistandard multi-band transceiver with a small VCO gain of 50MHz/V at 3.90GHz, PLL remains locked despite 45MHz frequency drift of VCO over [-30ºC, 85ºC]. Using an on-chip inductor, VCO covers from 3.15GHz to 4.60GHz, achieving -138.0dBc/Hz phase noise at 3.0MHz at 3.90GHz by drawing just 8.5mA from 1.60V supply in 0.13u CMOS process.Index Terms -Wide-range VCO, VCO temperature frequency drift, VCO fine-tune , on-chip inductor, PLL

A new method to improve the phase noise performance of the frequency synthesizer for UHF RFID

“…It can be seen that the temperature drift characteristics of VCO can be effectively reduced by using dual inductances. In parallel inductance mode, the L-T curve shows a negative temperature coefficient, while in single inductance mode, the L-T curve shows a positive temperature coefficient [7,8,9]. The curve of the capacitance varies with temperature shows a positive temperature trend.…”

Nanometrinių ir submikroninių integrinių grandynų įtampa ir skaitmeniniu būdu valdomiems generatoriams kūrimas ir tyrimas

“…Apžvelgiant FOM T kokybės funkcijos kitimą vertės kinta nuo −155,54 dBc/Hz (Jeong et al, 2012) iki −200,35 dBc/Hz (Saeidi et al, 2010).…”

“…Iš 1.10 paveikslo matoma, kad geriausias FOM T rezultatas yra −200,35 dBc/Hz (Saeidi et al, 2010). Šį bendrą rezultatą lemia labai mažas fazės triukšmas -(−138,00 dBc/Hz) bei maža vartojamoji galia -13,60 mW.…”

A 12GHz 67% tuning range 0.37pS RJ<inf>rms</inf> PLL with LC-VCO temperature compensation scheme in 0.13&#x03BC;m CMOS

“…It is also highly desirable that the PLL remains locked over a wide temperature range after initially being calibrated [1]- [4]. However, the oscillation frequency of an LC-VCO will decrease as the temperature increases and vice versa [2].…”

“…Once the frequency drift is beyond the coverage of the fine tuning band, the PLL will lose lock and the communication will be interrupted. To avoid this kind of failure, several solutions have been proposed which can be categorized into three main approaches: (I) Extending the fine tuning band coverage by increasing VCO gain [2]; (II) Reducing the frequency drift by adding redundancy into the LC-tank [1], [3]; (III) Optimizing the VCO control voltage during the coarse-tune calibration [4]. For the first solution, high VCO gain will increase the spur level and degrade the phase noise.…”