Wideband VCO With Simultaneous Switching of Frequency Band, Active Core, and Varactor Size

Hauspie, D.; Park, Eun-Chul; Craninckx, Jan

doi:10.1109/jssc.2007.899105

Cited by 91 publications

(20 citation statements)

References 16 publications

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“…Several studies were reported to reduce the Kvco and fste p variation in LC VCO. [14] and [15] only addressed the Kvco issue. And [16] proposed a new capbank structure to reduce the Kvco and fste p variations together, but it relied on arbitrary fractional scaling of the capacitance value over the sixteen tuning curves, which made it difficult to apply the method to an even wider tuning range and more tuning curves.…”

Section: B Loop Gain Calibrationmentioning

confidence: 99%

An FDC-based auto-calibration technique for ΔΣ fractional-N PLL

Shin

2011

2011 IEEE 54th International Midwest Symposium on Circuits and Systems (MWSCAS)

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Auto-calibration of veo frequency and loop gain is an essential process in PLL frequency synthesizers before the closed-loop locking process begins. It is crucial for the lock time and phase noise performances especially in a wide tuning-range fractional-N PLL frequency synthesizer. This paper reviews the design issues and limitations of the previous auto-calibration techniques. And a very simple and efficient auto-calibration method by using a high-speed frequency-to-digital converter (FDC) is proposed. It is highly suited for a .:ll: fractional-N PLL, and provides a fast and accurate calibration of the veo frequency and loop bandwidth over an octave tuning range.

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Section: B Loop Gain Calibrationmentioning

confidence: 99%

An FDC-based auto-calibration technique for ΔΣ fractional-N PLL

Shin

2011

2011 IEEE 54th International Midwest Symposium on Circuits and Systems (MWSCAS)

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“…With the rapid development of communication techniques, the requirements for RF transceivers has changed from meeting one standard to multimode, which means that the voltage‐controlled oscillator (VCO) should cover a wide‐frequency tuning range. Many methods have been reported for realising a wideband VCO [1–7]. In [1], the wide tuning range is achieved by using a digital‐controlled capacitor array.…”

Section: Introductionmentioning

confidence: 99%

Low‐phase‐noise wideband VCO with optimised sub‐nH inductor

Ren

Zhang

et al. 2015

Electron. lett.

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A wideband voltage-controlled oscillator (VCO) covering 2.24-4.95 GHz for multi-standard wireless applications is presented. Realised in TSMC 180 nm RFCMOS process, the VCO provides a phase noise <-124.2 dBc/Hz at a 1 MHz offset in the whole frequency range, while drawing 10 and 18 mA at 4.95and 2.24 GHz from a 1.8 V supply, respectively. The achieved tuning range is 75% and the core chip area is 0.51 mm².Introduction: With the rapid development of communication techniques, the requirements for RF transceivers has changed from meeting one standard to multimode, which means that the voltagecontrolled oscillator (VCO) should cover a wide-frequency tuning range. Many methods have been reported for realising a wideband VCO [1][2][3][4][5][6][7]. In [1], the wide tuning range is achieved by using a digitalcontrolled capacitor array. To achieve better phase-noise performance, an amplitude control calibration adopting a digital-to-analogue converter and an off-chip state machine was used, which increased the difficulty of design and the chip area. A combination of switch-controlled inductors and capacitors to allow a wider tuning range is another kind of solution, however, the parasitic resistance of the switches may degrade the quality (Q) of the inductor, and it is challenging to limit the degeneration of the phase-noise performance induced by the insertion of these switches [3]. A more popular way wideband VCO design is to utilise a transformer [4,[6][7], however, the low Q of the on-chip transformer may seriously degrade the phase noise. Adopting a switched VCO core could also cover a wide tuning range [5]; however, similarly, these switches are the main cause of poorer phase-noise performance. Though the traditional narrow band VCO could be utilised for wideband VCO design, the Q of the resonator varies with the frequency, especially when the frequency range is very wide. Thus, it is difficult to consider the trade-offs among phase noise, power consumption and chip area. In this Letter, we present a VCO that covers 2.24-4.95 GHz utilising an optimised high-Q sub-nH inductor with the traditional complementary current-biased structure. The VCO provides good phase-noise performance simultaneously with a wide tuning range of 75%. The frequency range can be extended to 32 MHz-4.95 GHz with the integrated dividers.

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“…To obtain wide frequency tuning range, varactor and switched-capacitor array are commonly utilized for CMOS VCOs [4], [5]. However, the varactor has smaller capacitance ratio, and the ratio of the maximum-to-minimum capacitance of a typical varactor in CMOS technology is around 4-6 [6].…”

Section: Introductionmentioning

confidence: 99%

A Wide-Tunable LC-Based Voltage-Controlled Oscillator Using a Divide-by-N Injection-Locked Frequency Divider

Hara

Okada

Matsuzawa

2010

IEICE Trans. Electron.

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This paper proposes a novel wideband voltage-controlled oscillator (VCO) for multi-band transceivers. The proposed oscillator has a core VCO and a tuning-range extension circuit, which consists of an injection-locked frequency divider (ILFD) and flip flop dividers. The two-stage differential ILFD generates quadrature outputs and realizes two, three, four, and six of divide ratio with very wide output frequency range. The proposed circuit is implemented by using a 90 nm CMOS process, and the chip area is 250 × 200 µm 2. The measured result achieves continuous frequency tuning range of 9.3 MHz-to-5.7 GHz (199%) with −210 dBc/Hz of figure-of-merit (FoM T).

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Wideband VCO With Simultaneous Switching of Frequency Band, Active Core, and Varactor Size

Cited by 91 publications

References 16 publications

An FDC-based auto-calibration technique for ΔΣ fractional-N PLL

An FDC-based auto-calibration technique for ΔΣ fractional-N PLL

Low‐phase‐noise wideband VCO with optimised sub‐nH inductor

A Wide-Tunable LC-Based Voltage-Controlled Oscillator Using a Divide-by-N Injection-Locked Frequency Divider

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Wideband VCO With Simultaneous Switching of Frequency Band, Active Core, and Varactor Size

Cited by 91 publications

References 16 publications

An FDC-based auto-calibration technique for &#x0394;&#x03A3; fractional-N PLL

An FDC-based auto-calibration technique for &#x0394;&#x03A3; fractional-N PLL

Low‐phase‐noise wideband VCO with optimised sub‐nH inductor

A Wide-Tunable LC-Based Voltage-Controlled Oscillator Using a Divide-by-N Injection-Locked Frequency Divider

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An FDC-based auto-calibration technique for ΔΣ fractional-N PLL

An FDC-based auto-calibration technique for ΔΣ fractional-N PLL