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The present work is concerned with studying and analysing the operation of the Colpitts oscillator based on operational amplifier with different technologies. During the study, two different operational amplifier types, TLV2374IEN and TL084ACN were used. First, the different operational amplifier parameters including; input offset voltage, input bias current, offset current, voltage gain, input impedance, and output impedance, as well slew rate were measured. Second, the effect of oscillator circuit inductance values (L) on the circuit parameters including; quality factor, signal frequency, inductor impedance, oscillator output impedance, amplification factor and output voltage gain were investigated, whenever the two proposed operational amplifiers were used. The quality factor, signal frequency, inductor impedance, and oscillator output impedance were observed to be affected by L variation. While, both the attenuation and amplification factors were shown to be affected by L till the value of around 860 µH, after this value a semi-saturation for the parameter values wasobserved. [ABSTRACT FROM AUTHOR]

The article proposes an all-embracing approach to designing a temperature compensated crystal oscillator in Keysight ADS CAD system, which allows: to investigate the conditions for the occurrence of self-oscillations in a given oscillator circuit; analyze the temperature-frequency characteristics of the resonator; form requirements for the frequency control function; simulate noise characteristics of the generator; optimize the circuit according to the given parameters. In contrast to the well-known numerical design of a thermally compensated crystal oscillator in SPICE programs with subsequent analysis of the results in a mathematical program, for example, Mathcad, the proposed method allows us to investigate the real shape of oscillations, the spectral purity of the output signal, take into account the nonlinear influence of the circuit and more subtle effects.

The purpose of this paper is to introduce a new chaotic oscillator. Although different chaotic systems have been formulated by earlier researchers, only a few chaotic systems exhibit chaotic behaviour. In this work, a new chaotic system with chaotic attractor is introduced for triangular wave non-linearity. It is worth noting that this striking phenomenon rarely occurs in respect of chaotic systems. The system proposed in this paper has been realized with numerical simulation. The results emanating from the numerical simulation indicate the feasibility of the proposed chaotic system. More over, chaos control, stability, diffusion and synchronization of such a system have been dealt with.

The purpose of this paper is to introduce a new chaotic oscillator. Although different chaotic systems have been formulated by earlier researchers, only a few chaotic systems exhibit chaotic behaviour. In this work, a new chaotic system with chaotic attractor is introduced for triangular wave non-linearity. It is worth noting that this striking phenomenon rarely occurs in respect of chaotic systems. The system proposed in this paper has been realized with numerical simulation. The results emanating from the numerical simulation indicate the feasibility of the proposed chaotic system. More over, chaos control, stability, diffusion and synchronization of such a system have been dealt with. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to introduce a new chaotic oscillator. Although different chaotic systems have been formulated by earlier researchers, only a few chaotic systems exhibit chaotic behaviour. In this work, a new chaotic system with chaotic attractor is introduced for triangular wave non-linearity. It is worth noting that this striking phenomenon rarely occurs in respect of chaotic systems. The system proposed in this paper has been realized with numerical simulation. The results emanating from the numerical simulation indicate the feasibility of the proposed chaotic system. More over, chaos control, stability, diffusion and synchronization of such a system have been dealt with. [ABSTRACT FROM AUTHOR]

This paper investigates a simple memristor emulator consisting of a diode bridge and a capacitor. It exhibits pinched hysteresis loops, and what is more striking is the higher frequency, as it operates up to greater than 5 MHz. Based on the proposed memristor, a higher-frequency Colpitts circuit was established. According to the mathematical model of the system, the system only possesses one unstable equilibrium point. Period doubling bifurcation, reverse periodic doubling bifurcation, different types of periodic and chaotic orbits, transient chaos, coexisting bifurcations and offset boosting are depicted. More interestingly, it has coexisting multiple attractors with different topologies, such as a chaotic attractor accompanied with periodic orbits, period-1 orbits with bicuspid structure and periodic-2 orbits with tridentate structure. Moreover, a hardware circuit using discrete components was fabricated and experimental measurements were consistent with the MATLAB numerical results, further confirming the real feasibility of the proposed circuit. [ABSTRACT FROM AUTHOR]

This paper demonstrates an on–off keying (OOK) super-regenerative quenching transmitter operating in 402–405 MHz MICs band applications. To reduce power consumption, the transmitter is controlled by a novel digital quenching signal controller that generates a digital control signal to start transmitter operation when a baseband signal is input to the transmitter. The digital signal controller consists of an envelope detector, a comparator, and a quench timer designed using a state machine to synchronize the operation between the digital controller and the input baseband signal. The transmitter consists of a Colpitts oscillator operating in double operating frequency followed by a frequency divider by 2; this configuration reduces system area and improves phase noise and signal spectrum. The proposed transmitter is implemented using UMC 130 nm CMOS technology and a 1.2 V supply. Simulation shows that the proposed transmitter can meet MICS band mask specifications with data rates up to 1 Mbps and total power dissipation of 537 uW. [ABSTRACT FROM AUTHOR]

This paper presents complete design guidelines for a typical fractional-order Colpitts oscillator (FOCO) with a non-ideal op-amp. These guidelines include effects of op-amp non-idealities like, open-loop dc gain, unity gain frequency and output resistance, into the design. The relation among these non-idealities and the frequency of oscillation ( f o ) are analytically established and an optimal configuration for FOCO is identified. The paper discusses multiple case studies on parametric variation, parameter sensitivities and oscillator stability. The proposed guidelines are validated with LTSpice simulations and practical experimentation along with step-by-step design examples. Practical results are compared with earlier reported FOCO which shows higher frequency and larger amplitude for the designed FOCO at a comparable THD. The proposed guidelines are generic in the sense that they are applicable for any order (including integer order), for any type of fractor realization technique, and also for any active element which has first-order behavioral model. [ABSTRACT FROM AUTHOR]

In this paper, two logarithmic non-linearities are proposed for a new four-dimensional chaotic system. The phase portrait, Lyapunov exponent, bifurcation, stability, and other dynamical features of the new chaotic system are all discussed. The multi-stability of the new chaotic system with coexisting attractors has been established. The adaptive backstepping control approach with proper Lyapunov functions is used in the control application to retrieve the unknown parameters of the system. To synchronise the states between the drive-response system, non-linear feedback control is used, as well as backstepping control to synchronise the states on the system's error dynamics. Op-amp circuits are used to create the electronic circuit design for a new chaotic system. The system's efficiency is confirmed using MATLAB numerical simulation. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to introduce a new chaotic oscillator. Although different chaotic systems have been formulated by earlier researchers, only a few chaotic systems exhibit chaotic behaviour. In this work, a new chaotic system with chaotic attractor is introduced. It is worth noting that this striking phenomenon rarely occurs in respect of chaotic systems. The system proposed in this paper has been realized with numerical simulation. The results emanating from the numerical simulation indicate the feasibility of the proposed chaotic system. More over, chaos control, stability, diffusion and synchronization of such a system have been dealt with.

A single-trim, highly accurate Colpitts-based frequency reference is presented. Our analysis shows that the Colpitts-topology outperforms the cross-coupled LC-topology in terms of temperature stability. Measurements on prototypes in a 0.13- $\mu \text{m}$ high-voltage CMOS silicon on insulator (SOI) process were carried out from −50 °C to 170 °C. Based on sample-specific single room temperature trim and batch calibration, our frequency reference achieves an accuracy of ±120 ppm for 16 samples from a single wafer utilized for extracting the batch-calibration polynomial and ±300 ppm for 48 samples across three wafers from the same batch. This is a 4 $\times $ improvement over related single-trim state-of-the-art solutions. Frequency drift due to aging, tested after a six-day 175 °C storage, is below 100 ppm. The oscillator core dissipates 3.5 mW from a 2.5-V supply and has 220-ppm/V supply sensitivity without supply regulation. [ABSTRACT FROM AUTHOR]

This paper investigates a simple memristor emulator consisting of a diode bridge and a capacitor. It exhibits pinched hysteresis loops, and what is more striking is the higher frequency, as it operates up to greater than 5 MHz. Based on the proposed memristor, a higher-frequency Colpitts circuit was established. According to the mathematical model of the system, the system only possesses one unstable equilibrium point. Period doubling bifurcation, reverse periodic doubling bifurcation, different types of periodic and chaotic orbits, transient chaos, coexisting bifurcations and offset boosting are depicted. More interestingly, it has coexisting multiple attractors with different topologies, such as a chaotic attractor accompanied with periodic orbits, period-1 orbits with bicuspid structure and periodic-2 orbits with tridentate structure. Moreover, a hardware circuit using discrete components was fabricated and experimental measurements were consistent with the MATLAB numerical results, further confirming the real feasibility of the proposed circuit.

The purpose of this paper is to introduce a new chaotic oscillator. Although different chaotic systems have been formulated by earlier researchers, only a few chaotic systems exhibit chaotic behaviour. In this work, a new chaotic system with chaotic attractor is introduced. It is worth noting that this striking phenomenon rarely occurs in respect of chaotic systems. The system proposed in this paper has been realized with numerical simulation. The results emanating from the numerical simulation indicate the feasibility of the proposed chaotic system. More over, chaos control, stability, diffusion and synchronization of such a system have been dealt with. [ABSTRACT FROM AUTHOR]

This paper demonstrates an on–off keying (OOK) super-regenerative quenching transmitter operating in 402–405 MHz MICs band applications. To reduce power consumption, the transmitter is controlled by a novel digital quenching signal controller that generates a digital control signal to start transmitter operation when a baseband signal is input to the transmitter. The digital signal controller consists of an envelope detector, a comparator, and a quench timer designed using a state machine to synchronize the operation between the digital controller and the input baseband signal. The transmitter consists of a Colpitts oscillator operating in double operating frequency followed by a frequency divider by 2; this configuration reduces system area and improves phase noise and signal spectrum. The proposed transmitter is implemented using UMC 130 nm CMOS technology and a 1.2 V supply. Simulation shows that the proposed transmitter can meet MICS band mask specifications with data rates up to 1 Mbps and total power dissipation of 537 uW.

A highly efficient push-push voltage-controlled oscillator (VCO) with a new inductive frequency tuning topology for (sub) terahertz frequencies is presented. The tuning technique is based on a variable inductance seen at the emitter node of a base-degenerated transistor. The variable inductor exhibits high quality factor and high tuning range due to the tunable transistor transconductance via bias current. Fabricated in a 0.13-$\mu\hbox{m} $ SiGe BiCMOS process, the VCO achieves a tuning range of 3.5% and an output power of $-$7.2 dBm at 201.5 GHz. The dc power consumption of the VCO is 30 mW, resulting in a high dc to RF power efficiency of 0.6% and a figure of merit $({\rm FoM}-{T})$ of $-$ 165, which is the highest FoM for any silicon-based VCO reported to date at this frequency range. To demonstrate the functionality of the tuning technique, three VCO prototypes at different oscillation frequencies, including one operating in the 222.7-229-GHz range, are implemented and measured. © 1963-2012 IEEE.

A highly efficient push-push voltage-controlled oscillator (VCO) with a new inductive frequency tuning topology for (sub) terahertz frequencies is presented. The tuning technique is based on a variable inductance seen at the emitter node of a base-degenerated transistor. The variable inductor exhibits high quality factor and high tuning range due to the tunable transistor transconductance via bias current. Fabricated in a 0.13-$\mu\hbox{m} $ SiGe BiCMOS process, the VCO achieves a tuning range of 3.5% and an output power of $-$7.2 dBm at 201.5 GHz. The dc power consumption of the VCO is 30 mW, resulting in a high dc to RF power efficiency of 0.6% and a figure of merit $({\rm FoM}-{T})$ of $-$ 165, which is the highest FoM for any silicon-based VCO reported to date at this frequency range. To demonstrate the functionality of the tuning technique, three VCO prototypes at different oscillation frequencies, including one operating in the 222.7-229-GHz range, are implemented and measured. © 1963-2012 IEEE.

We investigate in detail the nonlinear and chaotic dynamics of the Colpitts oscillator. We show that we can control the dynamics of the oscillator by either inductors, capacitors or resistors in the emitter or collector network. We find the bifurcation diagram and the Lyapunov exponent of the oscillator and investigate them. We also find bifurcation diagram in 2D space when two parameters from the mentioned parameters are variables. The 2D diagram shows the nonlinear behaviour of the system more clearly. [ABSTRACT FROM AUTHOR]

In this paper we introduce an approach to increase density of field-effect transistors framework an enhanced swing differential Colpitts oscillator. Framework the approach we consider manufacturing the oscillator in heterostructure with specific configuration. Several required areas of the heterostructure should be doped by diffusion or ion implantation. After that dopant and radiation defects should by annealed framework optimized scheme. We also consider an approach to decrease value of mismatch-induced stress in the considered heterostructure. We introduce an analytical approach to analyze mass and heat transport in heterostructures during manufacturing of integrated circuits with account mismatch-induced stress.

A millimeter-wave (mm-wave) voltage-controlled inductor (VCI) that is based on a series inductor–capacitor tank and that achieves large ratios of maximum to minimum inductance is proposed. For demonstration, a VCI with an inductance ratio of 4 is employed in a 22-nm CMOS silicon on insulator (SOI) Colpitts third-order-harmonic-extracted injection-locked (IL) oscillator (ILO) operating from 112.5 to 135 GHz. The ILO dc power consumption is 13 mW with a 1.2-V supply but is reduced to 5.6 mW with a 0.8-V supply when a 2-V back-gate voltage is applied. Due to the proposed VCI, the core of the mm-wave ILO occupies only 0.018 mm 2, the tunable operating range is ≥16%, and the added phase noise (PN) (~10 dB) is close to the theoretical prediction (20log(3) dB). [ABSTRACT FROM AUTHOR]

This letter presents a negative conductance ($G_{m}$)- and swing-enhanced Colpitts voltage-controlled oscillator (VCO) based on optimization of the capacitance ratio. In the proposed VCO structure, a current source typically used in conventional VCOs is replaced with an inductor to increase the output voltage swing. A current-reuse configuration is also adopted to decrease power consumption. Theoretical analyses and simulations show that the devised VCO with an optimized capacitance ratio exhibits enhanced $G_{m}$ and swing when compared to a conventional VCO. Measurements revealed a phase noise of −129.67 dBc/Hz at a 1-MHz offset frequency from the 2.2-GHz carrier, while power consumption was 2.2 mW from a 1.2-V supply voltage. This resulted in a figure-of-merit of −193.1 dBc/Hz. The proposed device was implemented using a 65-nm CMOS process. [ABSTRACT FROM AUTHOR]

We are exploring an optoelectronic oscillator featuring a Colpitts oscillator in its electrical path. The Colpitts oscillator generates high frequency electrical signals and exhibits dynamical behaviors such as periodic and bursting oscillations which can be easily monitored using a potentiometer. Inserting the Colpitts oscillator in the optoelectronic oscillator, we put forward the interaction between optical nonlinearity and electronic nonlinearity to obtain also complex dynamical behaviors. The temporal dynamics of the system with and without delayed feedback is investigated experimentally. It is shown that a wide variety of periodic and chaotic states can be excited and that there is an amplification of the signal frequencies. In particular, bursting, chaotic bursting and chaotic pulse-package oscillations with slow-fast temporal dynamics are experimentally observed in the system. [ABSTRACT FROM AUTHOR]

Frequency oscillator is one of the basic devices that can be used in most electrical, electronics and communications circuits and systems. There are many types of oscillators depending on frequency range used in an application such as audio, radio and microwave. The needed was appeared to use high and very high frequencies to make the rapid development of advanced technology Colpitts oscillator is one of the most common types of oscillator, it can be used for radio frequency (RF), that its output signal is often utilized at the basic of a wireless communication system in most application. In this research, a Colpitts oscillator is comprised from a bipolar junction transistor (BJT) amplifier with LC tank. This design is carrying out with a known Barkhausen criterion for oscillation. Firstly, is carried out using theoretical calculation. The secondary is carried out using simulation (Multisim 13). All the obtained result from the above two approaches are 10 MHz and 9.745 MHz respectively. This result is seen to be very encouraging. [ABSTRACT FROM AUTHOR]

In this work we present a novel technique to estimate the resonance frequency of LC chipless tags (inductor-capacitor parallel circuit) with improved sensitivity and linearity. The developed reader measures the power consumption of a Colpitts oscillator during a frequency sweep. The readout circuit consists of a Colpitts oscillator with a coil antenna, varactor diodes to change the oscillator frequency, analog circuitry to measure the power consumption and a microcontroller to control the whole system and send the data to a PC via USB. When an LC tag is inductively coupled to the oscillator, without contact, a maximum power peak is found. As shown by an experimental calibration using an LC tag made on FR4 substrate, the frequency of this maximum is related to the resonance frequency. Both parameters, power consumption and resonance frequency, present an excellent linear dependence with a high correlation factor (R2 = 0.995). Finally, a screen-printed LC tag has been fabricated and used as relative humidity sensor achieving a sensitivity of (−2.41 ± 0.21) kHz/% with an R2 of 0.946. [ABSTRACT FROM AUTHOR]

By the aid of nullor-mirror models of the second-generation current-controlled conveyor (CCCII) and applying the nodal admittance matrix (NAM) expansion method, the family of current-mode Colpitts oscillators employing four CCCIIs and three grounded capacitors is synthesized. Thirty-two Colpitts oscillators using CCCIIs are obtained in all. By using canonical number of components, the circuits can be easily integrated and the oscillation criterion and the oscillation frequency can be independently and electronically tuned by tuning bias currents of the CCCIIs. The paper-and-pencil analysis and Pspice simulation results have been included to support the synthesis method. [ABSTRACT FROM AUTHOR]

A chaotic radar system has been developed for through-wall detection and ranging of targets. The chaotic signal generated by an improved Colpitts oscillator is designed as a probe signal. Ranging to target is achieved by the cross-correlation between the time-delayed reflected return signal and the replica of the transmitted chaotic signal. In this paper, we explore the performance of the chaotic radar system for target detection and ranging through lossy media. Experimental results show that the designed chaotic radar has the advantages of high range resolution, unambiguous correlation profile, and can be used for through wall target detection and sensing.

This paper presents a new circuit topology of millimetre-wave quadrature voltage-controlled oscillator (QVCO) using an improved Colpitts oscillator without tail bias. By employing an extra capacitance between the drain and source terminations of the transistors and optimising circuit values, a low-power and low-phase-noise (PN) oscillator is designed. For generating the output signals with 90° phase difference, a self-injection coupling network between two identical cores is used. The proposed QVCO dissipates no extra dc power for coupling, since there is no dc-path to ground for the coupled transistors and no extra noise is added to circuit. The best figure-of-merit is −188.5, the power consumption is 14.98-15.45 mW, in a standard 180-nm CMOS technology, for 58.2 GHz center frequency from 59.3 to 59.6 GHz. The PN is −104.86 dBc/Hz at 1-MHz offset. [ABSTRACT FROM AUTHOR]

This paper presents a 1.8-mW 2.4-GHz channelized receiver for ISM-band applications. Unlike traditional ISM-band radios which typically require a phase-locked loop (PLL) for channelization, we propose a modified sliding-IF receiver architecture with a suitable local oscillator (LO) frequency plan utilizing a temperature-compensated thin film bulk acoustic-wave resonator (FBAR). This strategy completely eliminates the need for a PLL by directly dividing down the fixed FBAR oscillator frequency. An inductor-less current-reuse balun LNA is proposed allowing a low-power wideband matching as well as noise cancelling. The frequency conversion is achieved by a hybrid mixer, which stacks a switching mixer on a switched- gm mixer for current reuse. It also features good voltage headroom and common-mode noise rejection. The FBAR-based Colpitts oscillator achieves the phase noise of −144 dBc/Hz at 3.5-MHz offset. The measured RX gain, noise figure, and in-band IIP3 are 57.8 dB, 15.7 dB, and −18.5 dBm, respectively, without external crystal and on-chip inductors, which allows us to reduce the size and weight of the receiver system. It dissipates 0.86 mW (RX) and 0.92 mW (LO) from a single 1-V supply. [ABSTRACT FROM AUTHOR]

The maximum oscillation frequency depends on the oscillator topology and the loss of oscillator’s active and passive components. The oscillator phase noise, and hence the oscillator figure-of-merit ( $FOM$ ), degrades much faster than the well-known low-frequency expressions as the oscillation frequency reaches the maximum oscillation frequency. This paper covers the analysis and design of Colpitts oscillators with the best possible phase noise as the oscillation frequency approaches the maximum oscillation frequency while predicting the degradation in $FOM$. Experimental results corresponding to proof-of-concept differential Colpitts oscillator prototypes at 106 and 148 GHz that use a resonant biasing scheme to reduce phase noise, implemented in a 130-nm SiGe HBT BiCMOS technology, are presented. Ideally, the oscillator phase noise at a given frequency can be reduced by increasing the power consumption, while appropriately scaling the oscillator components. Such power scaling cannot be done indefinitely as it leads to impractical passive component values. Coupling identical oscillators is an alternate approach to enhance the phase noise. In this paper, a common-mode coupling scheme is introduced as a robust technique in reducing phase noise in millimeter wave frequencies. Experimental results of a 106-GHz 8-element common-mode coupled Colpitts oscillator, implemented in a 130-nm SiGe HBT BiCMOS technology, with a measured phase noise of −111 dBc/Hz at 1-MHz offset while consuming 90 mW are presented. [ABSTRACT FROM AUTHOR]