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Design of VCO with a Differential Tunable Active Inductor
N. Cheraghi Shirazi,R. Hamzehyan
International Journal of Machine Learning and Computing , 2013, DOI: 10.7763/ijmlc.2013.v3.263
Abstract: This paper presents a wide tuning rang CMOS voltage control oscillator (VCO) suitable for radio frequency operation. The oscillator based upon the classic LC-tuned negative-resistance topology, with a novel low voltage, high performance active inductor. In the proposed circuits' structure, the coarse frequency tuning is provided by the tunable active inductor, while the fine tuning is controlled by varactor. Using a 0.18μm CMOS process, complete pattern VCOs are designed in ADS. The output frequency is 5.5GHz. The measured phase noise in 1-MHz offset is -81dBc. The non existence of passive components causes VCO to have the smaller chip area than the circuit with passive inductors.
Ultra-Low Power, Low Phase Noise 10 GHz LC VCO in the Subthreshold Regime  [PDF]
Davood Fathi, Aboozar Gorbani Nejad
Circuits and Systems (CS) , 2013, DOI: 10.4236/cs.2013.44047

A new design for an ultra-low power, low phase noise differential 10 GHz LC voltage-controlled oscillator (VCO) which is biased in the subthreshold regime, is presented in the 0.18 μm CMOS process, for the first time. The designed circuit topology is an NMOS only cross-coupled LC-tank VCO which has an extra symmetric centre tapped inductor between the source ends of the cross-coupled transistors. Using this inductor leads to an improvement of the phase noise of VCO about 3.5 dB. At the supply voltage of 0.46 V, the output phase noise is -107.8 dBc/Hz at 1 MHz offset frequency from the carrier frequency of 10.53 GHz, so that the dc power consumption is only 0.346 mW. Tuning range is between 10.53 GHz to 11.35 GHz which is 7.5% and the figure of merit is -193.8 dB, which this result shows that this is the first VCO design in the subthreshold regime at this frequency. This VCO can be used for multi-standard wireless LAN communication protocols 802.11a/b/g easily by a frequency division of 2 or 4 respectively.

An 11.5 GHz Cascode VCO with Low Phase Noise in InGaP/GaAs HBT Technology
Shreshtha Bhanu,Kennedy Gary,Kim Nam-Young
IETE Technical Review , 2007,
Abstract: A MMIC cascode VCO is designed, fabricated, and characterized for an X-band Low Noise Block(LNB) system using InGaP/GaAs HBT technology. A phase noise of -116.4 dBc/ Hz at an offset frequency of 1 MHz and an output power of 1.3 dBm is obtained at 11.526 GHz using a 3 V bias and a current consumption of 11 mA. The characteristics of this VCO are comparatively better than those with the different VCO configurations fabricated with other technologies. Also, simulated oscillation frequency and second harmonic suppression agree with the measured results. And, phase noise is improved due to the use of the small value of series resistor of inductor in frequency determining network plus the InGaP ledge in the HBT. The chip size is 830 x 781μm 2.
A Low Phase Noise, Low Power and Wide Tuning Range VCO with Filtering Technique in ISM Band  [PDF]
Masoud Sabaghi, Saeid Marjani, Abbas Majdabadi
Circuits and Systems (CS) , 2016, DOI: 10.4236/cs.2016.72006
Abstract: In this paper, a novel voltage controlled oscillator (VCO) with low phase noise, low power consumption and wide tuning range in the industrial, scientific and medical (ISM) band is proposed for communication systems applications. For improving the phase noise, filtering technique is used and VCO is designed with TSMC CMOS 0.18 μm technology and the power supply is 1.5 V. The simulation results with advanced design system (ADS) shows that phase noise in 1 MHz offset frequency from the carrier is -122 dBc/Hz and tuning range is 2 to 2.8 GHz. The power consumption of the core is 2.49 mW.
Simple Simulated Inductor, Low-Pass/Band-Pass Filter and Sinusoidal Oscillator Using OTRA  [PDF]
Raj Senani, Abdhesh Kumar Singh, Ashish Gupta, Data Ram Bhaskar
Circuits and Systems (CS) , 2016, DOI: 10.4236/cs.2016.73009
Abstract: Although a variety of applications of the OTRAs have been reported in literature, the pole of the transresistance gain Rm of the OTRA has been usually considered to affect the performance of the circuits due to being parasitic. In this paper, the pole of the OTRA has been used to evolve some simple OTRA-based active-R circuits for realizing a synthetic inductor, single resistance controlled oscillator and low-pass/band-pass filter. The workability of all the proposed circuits has been verified by SPICE simulations and all the new circuits have been found to work as predicted by theory. The exemplary propositions suggest that it is worthwhile to further investigate new circuit designs using OTRA-pole.
Design of Low Power VCO using >2G Hz Technology
suchita subhash uparkar
International Journal of Advances in Engineering Sciences , 2011,
Abstract: The design challenges are increasing with the increase in demand for low power, high-frequency wireless systems. The reasons are poor phase noise performance of integrated VCO and large area taken by the loop filter. Many recent reporting show that with careful design, on-chip VCO can be made to give comparable phase noise performance with off-chip VCO. In this paper we have presented a design of a ring oscillator which is implemented in CMOS.
A Low Power Low Phase Noise Lc Voltage-Controlled Oscillator
Hai Feng Zhou;Kam-Man Shum;Ray C. C. Cheung;Quan Xue;Chi Hou Chan
PIER Letters , 2013, DOI: 10.2528/PIERL13011015
Abstract: A low phase noise CMOS complementary cross-coupled LC-tank voltage-controlled oscillator (VCO), implemented with TSMC 0.18 m 1P6M CMOS technology, is presented. Double pair pseudo-resistance transistors biased by the tapped center of the inductor are utilized to reduce the DC bias current. The circuit consumes 1.55 mA from a 1.5 V supply voltage which saves up to 52.4% power, compared with the conventional one. Furthermore, an adaptive body biasing technique (ABB) is used to overcome the effect of PVT variations. The VCO is tunable from 2.58 to 3.07 GHz and has a phase noise -122.7 dBc/Hz at 1 MHz offset from the 3 GHz carrier. The Figure of Merit (FOM) of the proposed VCO is -188.8 dBc, and the figure of merit including the tuning range (FOM ) is -193.5 dBc.
Design of Wide Band CMOS VCO with Common Source Transformer Feedback Topology  [PDF]
Meng-Ting Hsu, Ying-Hsiang Huang, Cheng-Chuan Chung
Wireless Engineering and Technology (WET) , 2013, DOI: 10.4236/wet.2013.41004

This paper demonstrates wide-band CMOS VCO based on the transformer feedback from traditional circuit to our proposed work. The start up condition of the traditional cross-coupled pair is expressed by the high frequency model. The wide band technique of this structure is derived with the help of the high frequency model of the transistor. Therefore, the wide band CMOS VCO based on the common source transformer feedback topology can achieves the high performance in the low voltage and low phase noise. The measurement result of the VCO exhibits the figure of merit, core power consumption and output power at supply voltage 0.8 V are –193.1 dBc/Hz, 4.4 mW and 2.3 dBm, respectively. The phase noise is –124.3 dBc/Hz at 1 MHz offset under the operation frequency 5.8 GHz. And the tuning range of the circuit can obtain 28%, this VCO is fabricated in TSMC 0.18 μm 1P6MCMOS process.

A Subthreshold Low-Voltage Low-Phase-Noise CMOS LC-VCO with Resistive Biasing  [PDF]
Jungnam Bae, Saichandrateja Radhapuram, Ikkyun Jo, Takao Kihara, Toshimasa Matsuoka
Circuits and Systems (CS) , 2015, DOI: 10.4236/cs.2015.65014
Abstract: This paper presents a low-phase-noise LC voltage-controlled oscillator (LC-VCO) with top resistive biasing in subthreshold region. The subthreshold LC-VCO has low-power and low-phase-noise due to its high transconductance efficiency and low gate bias condition. The top resistive biasing has more benefit with the feature of phase noise than MOS current source since it can support the low-noise characteristics and large output swing. The LC-VCO designed in 130-nm CMOS process with 0.7-V supply voltage achieves phase noise of -116 dBc/Hz at 200 kHz offset with tuning range of 398 MHz to 408 MHz covering medical implant communication service (MICS) band.
7GHz and 25.8GHz LC VCO Using 0.18 μm Mixed Signal CMOS Process
Youngho Jung,Hee Sauk Jhon,In Man Kang,Jong Duk Lee
Elektrika : Journal of Electrical Engineering , 2007,
Abstract: This paper presents the design and fabrication of a LC voltage-controlled oscillator (VCO) in 0.18 μm mixed signal CMOS process for operating at 7 GHz and 25.8 GHz. To obtain the high-quality factor inductor in LC resonator, patterned-ground shields (PGS) is placed under the symmetric inductor to reduce the effect of image current of resistive Si substrate. Fabricated VCO operated from 7.04 GHz to 7.34 GHz is tuned by accumulation-mode MOS varactor. The measured phase noise of 7/04 GHz VCO was -83.24 dBc/Hz at the offset of 1 MHz. Also, phase noise of 25.8 GHz VCO was -72.99 dBc/Hz at the offset of 1 MHz. The power consumption of 7 GHz and 25.8 GHz VCO was 6.48 mW and 18.61 mW, respectively
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