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

Hauspie, D.; Park, Eun-chul; Craninckx, Jan; Côme, B.

doi:10.1109/esscir.2006.307478

Cited by 17 publications

(23 citation statements)

References 15 publications

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“…However, as the tuning range of a VCO is increased and exceeds the typical 20% range obtained in many designs, new problems and trade-offs appear that need a solution. In this design we have tackled the two main problems encountered in wideband LC-VCOs [5]. First, the negative resistance required to maintain oscillation varies a lot over the frequency range, leading to significant overhead when a fixed active core is used.…”

Section: To 5-ghz Voltage-controlled Oscillatormentioning

confidence: 99%

“…At power-up time, before actual operation, both the frequency and the frequency sensitivity of the VCO must be measured and stored in a look-up table for correct operation. The setting chosen must be such that the VCO gain is kept proportional to the frequency over the entire frequency range, as this keeps the PLL bandwidth constant [5]. Figure 1.4(a) shows a selected set of the measured frequency response of the VCO.…”

Section: Circuit Implementationmentioning

confidence: 99%

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Software‐Defined Radio Front Ends

Hueber¹,

Staszewski

2010

Multi‐Mode/Multi‐Band RF Transceivers for Wireless Communications

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The ultimate dream of every software-defined radio (SDR) front-end architect is to deliver a radio-frequency (RF) transceiver that can be reconfigured into every imaginable operating mode, in order to comply with the requirements of all existing and even upcoming communication standards. These include a large range of modes for cellular (2G-2.5G-3G and further), WLAN (802.11a/b/g/n), WPAN (Bluetooth, Zigbee, etc.), broadcasting (DAB, DVB, DMB, etc.), and positioning (GPS, Galileo) functionalities. Obviously, each of them has different center frequency, channel bandwidth, noise levels, interference requirements, transmit spectral mask, and so on. As a consequence, the performances of all building blocks in the transceiver must be reconfigurable over an extremely wide range, requiring ultimate creativity from the SDR designer.Reconfigurability is a requirement for SDR functionality, but often one forgets that it can also be an enabler for low power consumption. Indeed, once flexibility is built into a transceiver, it can be used to adapt the performance of a radio to the actual circumstances instead of those implied by the worst-case situation of the standard. Since linearity, filtering, noise, bandwidth, and so on, can be traded for power consumption in the SDR, a smart controller is able to adapt the radio at runtime to the actual performance required, and hence can reduce the average power consumption of the SDR.In this chapter, several important innovations and concepts are presented that bring this ultimate dream closer to reality. These include circuits for wideband local oscillator (LO) synthesis, multifunctional receiver and transmitter blocks, and novel ADC (analog-to-digital converter) implementations. The result of all this is integrated in the world's first SDR transceiver covering the frequency range from 174 MHz to 6 GHz, implemented in a 1.2-V 0.13-µm CMOS technology.

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Section: To 5-ghz Voltage-controlled Oscillatormentioning

confidence: 99%

Section: Circuit Implementationmentioning

confidence: 99%

Software‐Defined Radio Front Ends

Hueber¹,

Staszewski

2010

Multi‐Mode/Multi‐Band RF Transceivers for Wireless Communications

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“…Tuning ranges of 20% are typical but can be as high as 30% [21]. Recent results suggest that ranges approaching 50% are possible [22].…”

Section: Phase-locked Loopsmentioning

confidence: 99%

Software‐Defined Transceivers

Cafaro

Stengel

2010

Multi‐Mode/Multi‐Band RF Transceivers for Wireless Communications

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“…An obvious drawback of the above method is a reduced tuning range for a given varactor, this is contrary to the intentions of large tuning range. In [8], varactor size is changeable according to the resonate frequency to keep K vco constant, but a detection and calibration loop of K vco is needed to properly choose the size of varactor when the frequency is changed, this significantly increases the design complexity of the VCO and the loop setting time of the PLL.…”

Section: Introductionmentioning

confidence: 99%

“…To suppress K vco variation in conventional wideband LC-VCO, several techniques have been proposed [6][7][8]. In [6], an equivalent variable inductor that consists of an inductor and a fine-tuned varactor is used to cancel out the K vco variation.…”

Section: Introductionmentioning

confidence: 99%

A wideband LC-VCO with small VCO-gain fluctuation for mobile DTV application

Gao

Yan

et al. 2011

Analog Integr Circ Sig Process

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A novel wideband LC-tuned VoltageControlled Oscillator (VCO) with small VCO-gain (K vco ) fluctuation was developed. A combination of parallel switched varactor array and switched capacitor array was introduced into conventional LC-tank, and both arrays are controlled by the same code and switched simultaneously.In this way small VCO-gain fluctuation was achieved and no additional calibration process of K vco was needed. The proposed resonator was applied to two wideband LC-VCOs implemented in a 0.25 lm CMOS technology for mobile DTV application. Each VCO achieves a K vco fluctuation of less than 16%, which is one-fourth of that in a conventional wideband LC-VCO, with a tuning range of more than 46%. The whole output frequency range is from 0.82 to 1.85 GHz, and the power consumption varies accordingly from 6.4 to 3 mA from a 2.5 V supply. The measured phase noise is -127 dBc/Hz at 1 MHz offset from a 1.17 GHz carrier.

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

Cited by 17 publications

References 15 publications

Software‐Defined Radio Front Ends

Software‐Defined Radio Front Ends

Software‐Defined Transceivers

A wideband LC-VCO with small VCO-gain fluctuation for mobile DTV application

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