Мathematical modeling of voltage-controlled oscillators with  the colpitts and clapp topology

Ulansky, Vladimir; Fituri, M.S.; Machalin, I. A.

doi:10.18372/1990-5548.19.667

Cited by 6 publications

(4 citation statements)

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“…We can classify VCOs as negative impedance (NI) and NDR oscillators. In the NI VCOs, the real part of the input impedance has a negative sign [51,52]. This negative resistance compensates for the losses in the tank circuit.…”

Section: Negative Differential Resistance Voltage-controlled Oscillatorsmentioning

confidence: 99%

Two-Terminal Electronic Circuits with Controllable Linear NDR Region and Their Applications

Ulansky

Raza

Milke³

2021

Applied Sciences

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Negative differential resistance (NDR) is inherent in many electronic devices, in which, over a specific voltage range, the current decreases with increasing voltage. Semiconductor structures with NDR have several unique properties that stimulate the search for technological and circuitry solutions in developing new semiconductor devices and circuits experiencing NDR features. This study considers two-terminal NDR electronic circuits based on multiple-output current mirrors, such as cascode, Wilson, and improved Wilson, combined with a field-effect transistor. The undoubted advantages of the proposed electronic circuits are the linearity of the current-voltage characteristics in the NDR region and the ability to regulate the value of negative resistance by changing the number of mirrored current sources. We derive equations for each proposed circuit to calculate the NDR region’s total current and differential resistance. We consider applications of NDR circuits for designing microwave single frequency oscillators and voltage-controlled oscillators. The problem of choosing the optimal oscillator topology is examined. We show that the designed oscillators based on NDR circuits with Wilson and improved Wilson multiple-output current mirrors have high efficiency and extremely low phase noise. For a single frequency oscillator consuming 33.9 mW, the phase noise is −154.6 dBc/Hz at a 100 kHz offset from a 1.310 GHz carrier. The resulting figure of merit is −221.6 dBc/Hz. The implemented oscillator prototype confirms the theoretical achievements.

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Section: Negative Differential Resistance Voltage-controlled Oscillatorsmentioning

confidence: 99%

Two-Terminal Electronic Circuits with Controllable Linear NDR Region and Their Applications

Ulansky

Raza

Milke³

2021

Applied Sciences

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“…To obtain the calculated values of the voltage and current thresholds, we solve Equations (28) and (29) and use Equations (3), (4), and (22)- (25). The results of calculations and SPICE simulations with the help of Multisim (ed.…”

Section: Threshold Calculated Value Simulated Value Error %mentioning

confidence: 99%

“…A distinctive feature of the first-class oscillators is the presence of a negative real part in the input impedance. Examples of such oscillators are numerous Colpitts, Clapp, Hartley oscillator circuits, and their modifications [27][28][29][30], as well as cross-coupled CMOS oscillators [31][32][33][34]. The second class of microwave oscillators supposes to use a tunnel diode or a Gunn diode [35,36], which have an NDR region in the N-type current-voltage characteristics.…”

Section: Lc Oscillatormentioning

confidence: 99%

Electronic Circuit with Controllable Negative Differential Resistance and its Applications

2019

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Electronic devices and circuits with negative differential resistance (NDR) are widely used in oscillators, memory devices, frequency multipliers, mixers, etc. Such devices and circuits usually have an N-, S-, or Λ-type current-voltage characteristics. In the known NDR devices and circuits, it is practically impossible to increase the negative resistance without changing the type or the dimensions of transistors. Moreover, some of them have three terminals assuming two power supplies. In this paper, a new NDR circuit that comprises a combination of a field effect transistor (FET) and a simple bipolar junction transistor (BJT) current mirror (CM) with multiple outputs is proposed. A distinctive feature of the proposed circuit is the ability to change the magnitude of the NDR by increasing the number of outputs in the CM. Mathematical expressions are derived to calculate the threshold currents and voltages of the N-type current-voltage characteristics for various types of FET. The calculated current and voltage thresholds are compared with the simulation results. The possible applications of the proposed NDR circuit for designing single-frequency oscillators and voltage-controlled oscillators (VCO) are considered. The designed NDR VCO has a very low level of phase noise and has one of the best values of a standard figure of merit (FOM) among recently published VCOs. The effectiveness of the proposed oscillators is confirmed by the simulation results and the implemented prototype.

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“…They are widely generated from voltage-controlled oscillators (VCOs) injected in phase lock loops (PLLs) to up-convert or down-convert signals. There are several different LC VCO topologies, but Copitts and Clapp topologies have attracted more attention in both research and deployment [1], [2], [3], [4].…”

Section: Introductionmentioning

confidence: 99%

A Novel Varactorless Tuning Technique for Clapp VCO Design Using Tunable Negative Capacitor to Increase Frequency-Tuning Range

Nguyen

Seo

2021

IEEE Access

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In this paper, a varactorless frequency-tuning method for Clapp voltage-controlled oscillator (VCO) design is proposed aiming at increasing frequency-tuning range (FTR) in comparison with the conventional varactor-based counterpart. The proposed structure uses a tunable non-Foster (negative) capacitor (TNC) to sweep oscillation frequency instead of a varactor. The analytical demonstration points that total tuning dynamic (TTD) qualitatively representing FTR is traditionally limited to varactor's tuning dynamic (TD); while the TNC-based VCO can exhibit very-high TTD, at least over TNC's TD capacity, if the maximum negative capacitance is appropriately designed, which can tolerate the TD requirement on the tuning component for wideband operation. Circuit realization of TNC is based on a grounded negative impedance inverter (NII) with cross-coupled transistors whose gate voltage controls capacitance. A simulation script using a real discrete transistor model with the realized TNC shows that FTR can be covered with TTD of 2.46 units while the TD of the non-Foster tuning component is only 1.32 units, validating the advantageous operation as well as practical realization possibility of the proposed VCO. In addition, phase noise performance is remained below −100 dBc/Hz for every tuning voltages at 1 MHz offset frequency, while figure of merit comprising FTR effect (FOMT) can be achieved in range of 140-180, which is similar to the existing state-of-the-art VCOs.INDEX TERMS JFET, Colpitt and Clapp VCOs, negative impedance inverter, non-Foster capacitor, negative resistance.

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Мathematical modeling of voltage-controlled oscillators with the colpitts and clapp topology

Cited by 6 publications

References 0 publications

Two-Terminal Electronic Circuits with Controllable Linear NDR Region and Their Applications

Two-Terminal Electronic Circuits with Controllable Linear NDR Region and Their Applications

Electronic Circuit with Controllable Negative Differential Resistance and its Applications

A Novel Varactorless Tuning Technique for Clapp VCO Design Using Tunable Negative Capacitor to Increase Frequency-Tuning Range

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