Oscillators and amplifiers in integrated E-plane technique

An overview is presented of solid-state oscillators and amplifiers realized in E-plane technology. The circuit topology, basic design procedures, and performance characteristics are described and compared. Gunn oscillators, IMPATT oscillators, transistor oscillators, injection-locked Gunn oscillators, and transistor amplifiers are surveyed. Gunn and transistor oscillators have been realized successfully for frequencies from 10 to 110 GHz, thus covering almost the entire frequency range suitable for E-plane technology. IMPATT oscillators are difficult to design and to reproduce in quasi-planar form because of the high impedance ratio that must be overcome by the circuit. E-plane FET amplifiers have been built for frequencies up to 60 GHz     

On the systematic synthesis of OTA-based Wien oscillators

A NAM expansion method for systematic synthesis of OTA-based Wien oscillators is given. Moreover, the NAM expansion method for four different classes of the oscillators is considered. The class I oscillators employ three OTAs, the class II oscillators employ four OTAs, the class III oscillators employ five OTAs, and the class IV oscillators employ six OTAs. Each class has 32 different forms, resulting in 128 Wien oscillators using OTAs. Having used grounded capacitors, the circuits are easy to be integrated and their parameters can be tuned electronically through tuning bias currents of the OTAs. The MULTISIM simulation results have been included to support the generation method.     

Some comments on potential and space charge distribution in a symmetrical magnetic diode

A general, simple and systematic method for generating RC harmonic oscillators is proposed. These oscillators, which are classified into fifteen oscillator families, are constructed by cross-cascading easily designed first-order circuits. The method is developed by eighteen examples. Single-resistor controlled oscillators, grounded-capacitor oscillators and two-phase oscillators can be designed. It is also shown that GIC circuits can be obtained from some of these oscillator circuits.     

Operating principles of reactance-less memristor-based oscillators

The aspects of design of reactance-less oscillators based on memristors are considered. The requirements on load elements in the circuits of such oscillators are formulated. The equations describing the dynamical behavioral of the memristor oscillators with the use of linear-drift models are presented. Examples of the analysis and synthesis of oscillators using such equations are presented. The possibility of generation in the circuits under consideration of periodic signals with a waveform close to harmonic oscillations is shown.     

A hyperchaotic memristor system with exponential and discontinuous memductance function

Most of the memristor chaotic and hyperchaotic oscillators discussed in the literatures use the cubic flux controlled memristor model. The drawback of this model is that in spite of knowing the terminal voltage polarity, one cannot easily determine whether the memductance increase or decrease. Hence we propose new memristor hyperchaotic oscillators derived using exponential memductance and discontinuous memductance functions. Dynamical analysis of the proposed oscillators are conducted using equilibrium points, stability of equilibrium, Eigen values and Lyapunov exponents. Bifurcation plots are derived to understand the parameter dependence of the proposed oscillators. Multistability and coexisting attractors are exhibited by these memristor oscillators.     

Microstrip active path array with beam scanning

A four-element microstrip active path array with beam scanning is described consisting of locked path oscillators with DC bias phase control. The radiating elements are formed by transistor oscillators whose frequency is controlled by a rectangular patch. The oscillators are locked to an external source. Control of the radiated phase is achieved by varying the bias on the transistor. Close to 360 degrees of radiated phase control can be achieved from each element by locating two oscillators on each patch. Measured results indicate that beam scanning in excess of 40 degrees can be achieved.<>     

Effects of changes in operating conditions on the phase of a frequency-locked Gunn oscillator in X band

The frequency and phase-locking properties of solid-state microwave oscillators are of current interest in the contexts of phase control of oscillators, and the combining of a number of oscillators to achieve improved output power. A particular case of interest is that of the phased array antenna, in which the dual functions of power combination and beam steering are needed. In the latter case, it may be necessary to have control over the relative phases of a large number of oscillators locked to a common frequency. In a phased array, there is a special need to set the relative phases of the oscillators accurately, and to maintain the accuracy of the settings as parameters such as ambient temperature vary. A number of workers have investigated the frequency-locking properties of negative-resistance oscillators, but no comprehensive study of their phase-locking properties has been reported.     

Transformation of oscillators using Op Amps,unity gain cells and CFOA

A new approach in the systematic synthesis of current conveyor based active RC canonic oscillators is given. The synthesis procedure is based on the generalized systematic synthesis framework using admittance matrix expansion. The resulting derived oscillators include many novel oscillators, using various types of current conveyors and inverting current conveyors. The oscillators considered in this paper uses the minimum number of passive elements namely two capacitors and three resistors necessary to have independent control on the condition of oscillation and on the frequency of oscillation. The generated oscillators employ two grounded capacitors and have the advantage of their ability to absorb parasitic element effects. Three classes are considered in this paper, class I oscillators have a common node between one of the capacitors and one of the two grounded resistors. Class II oscillators have a common node between one of the capacitors and the floating resistor. Class III has all three resistors being grounded and one of them shares a node with one of the capacitors. It should be noted that this is the first paper in the literature to use nodal admittance matrix expansion in the generation of current conveyor oscillators. Spice simulation results are included to support the theory. The proposed method can be generalized to other active devices.     

注频锁相振荡器阵列的低相位噪声信号产生方法

提出了注频锁相振荡器阵列的拓扑结构及相位噪声模型,根据该模型简要推导了注频锁相振荡器阵列相位噪声的计算公式并对整个阵列的相位噪声进行了分析,完成了1×4单元注频锁相振荡器阵列相位噪声的测试,测试结果与理论分析吻合,最终得出了注频锁相振荡器阵列的低相位噪声信号产生方法。     

On the generation of CCII and ICCII oscillators from three Op Amps oscillator

A new quadrature oscillator using two current conveyors (CCII) and two inverting current conveyors (ICCII) is generated from a three Op Amp two integrator loop oscillator. The proposed oscillator is generalized and it is found that it is a member of a family of 64 oscillator circuits using combination of CCII and ICCII. Four of the reported oscillators are floating. The three Op Amps oscillator is also found to be the reference oscillator circuit in the generation of two basic CCII two integrator loop grounded passive element oscillators. The nodal admittance matrix (NAM) expansion is used to show the basic steps in the generation of the two alternatives CCII grounded passive element oscillators. Each of the two CCII oscillators is a member of a family of sixteen oscillator circuits using combination of CCII and ICCII. Two of the reported oscillators are floating and their adjoint oscillator circuits are not floating. Simulation results are included.     

Experiments on integrated gallium-arsenide f.e.t. oscillators at X band

Experimental results obtained with GaAs f.e.t. oscillators at X band are described. It is demonstrated that the output power of f.e.t. oscillators is sufficient to drive X band mixers. The noise measure of these oscillators is competitive with Gunn devices, and can be reduced further.     

Some effects of spatially nonuniform pumping in pulsed optical parametric oscillators

Previous analyses of the large signal operation of optical parametric oscillators have considered uniform plane-wave pump beams. These analyses are not adequate to describe the behavior of efficient pulsed oscillators pumped by beams having nonuniform intensity profiles and pulse durations that are short enough that the steady-state transverse modes of the oscillator cavity do not become established. This situation is typical of oscillators with plane-parallel cavities pumped byQ-switched lasers. This paper theoretically and experimentally investigates the behavior of such oscillators when pumped with beams having Gaussian intensity profiles. Each of the three basic external optical parametric oscillators are considered. For simplified cases it is shown that the response to a Gaussian pump beam is quantitatively and qualitatively much different than that predicted by the uniform plane-wave calculations. Experimental results in fair agreement with these calculations are presented. More importantly, uniform plane-wave behavior was observed by using an aperture to probe a small section of the pump beam transmitted through the oscillator. This useful technique gives a sensitive indication of the oscillator operation and, at present, it is the most accurate means of measuring thresholds in pulsed oscillators. As a result of our calculations and experiments, previous experimental observations that were puzzling are now well understood.     

Optical control of microwave semiconductor devices

The use of optically controlled devices to perform a range of circuit functions is reviewed. The optical control of amplifier performance is discussed. The optical control of two- and three-terminal oscillators and optically pumped mixers is discussed. Among the active devices treated are Gunn and IMPATT oscillators; MESFET and HEMT amplifiers, oscillators, and mixtures; and diode mixers. Future directions for research in this area are discussed     

A Time-Domain Model for Predicting the Injection Locking Bandwidth of Nonharmonic Oscillators

A delay-based model in the time domain is introduced to describe injection locking in nonharmonic oscillators, such as ring or relaxation oscillators. Using this model, the locking bandwidth of differential ring oscillators is derived. The model predictions are verified against simulations and measurements of a four-stage ring oscillator circuit built using discrete components     

Effect of selective tungsten as a polysilicon shunt on CMOS ring-oscillator performance

Selective tungsten is applied as a polysilicon shunt to CMOS ring oscillators specifically designed to be interconnect limited. The tungsten shunted ring oscillators operate at a frequency almost twice that of nonshunted oscillators. Shunting of source/drains as well as gates leads to further performance enhancements. Similar improvements are demonstrated for VLSI circuits.     

Chaos Synchronization in Complex Oscillators Networks with Time Delay via Adaptive Complex Feedback Control

This paper investigates the problem of chaos synchronization in complex oscillators networks. An adaptive complex feedback controller is designed to realize chaos synchronization in complex oscillators networks. The adaptive complex feedback controller consisting of real part controller and imaginary part controller. The real part controller and the imaginary part controller control the real part system and the imaginary part system of complex oscillators system of complex dynamical networks, respectively. Chaos synchronization in complex oscillators networks with constant delay and chaos synchronization in complex oscillators networks with time-varying coupling delay are researched. Finally, the numerical simulations show the effectiveness of theoretical analysis.     

Start-up and frequency stability in high-frequency oscillators

Start-up criteria in harmonic oscillators are explored. Conventional criteria for start-up prediction are shown to be necessary but not always sufficient for high-frequency oscillators, due to the effects of parasitic elements. Design methods are derived to allow design of reliable oscillators with a well-defined frequency of oscillation. The theory is confirmed with the design, fabrication, and characterization of a 2-GHz monolithic LC oscillator     

Microwave Integrated Oscillators for Broad-Band High-Performance Receivers

The design and development of a variety of microwave integrated circuit oscillators for use in integrated broad-band high-performance receiving systems is described. Examples of various thin-film microstrip oscillators directed to this application are provided including: 1) fixed-frequency Gunn-effect oscillators covering C to Ku band; 2) X-band varactor-tuned Gunn-effect oscillators providing up to 15 percent tuning bandwidth; 3) S-band step-tuned transistor oscillator assembly with better than half-octave digital tuning range; 4) L-band varactor-tuned transistor oscillator with almost an octave tuning range.     

Wide-Band Varactor-tuned Coaxial Oscillators

An experimental investigation into the effects of package and circuit reactances on wide-band varactor-tuned oscillators is described. The results are used to design an X-band Gunn coaxial oscillator with a tuning range in excess of 3 GHz. It is shown that the stray reactance, junction capacitance, and bond-wire inductance affect the varactor tuning characteristics. The characteristics are conveniently displayed by the reflection phase variation with tuning voltage and frequency. A general theory for wide-band varactor-tuned oscillators is presented which is related to the impedance characteristics. These results are used to design three coaxial varactor-tuned oscillators. The first two oscillators are series arrangements while the third oscillator is a parallel arrangement. A simple circuit technique is used to improve the tuning range of each arrangement. This technique is shown to increase the coupling to the varactor diode and decrease the oscillator Q by reactance compensation.     

Phased arrays based on oscillators coupled on triangular and hexagonal lattices

Phased arrays have been proposed in which a two-dimensional array of voltage-controlled oscillators coupled to nearest neighbors provides excitations for the radiating elements which are properly phased to result in a steerable radiated beam. These arrays have been arranged on a rectangular lattice and the beam is steered by tuning the oscillators along the four edges of the array. Proposed here are similar arrays in which the oscillators are coupled on a triangular lattice or a hexagonal lattice and provide excitations for radiating elements similarly disposed in a planar triangular array. Beam steering is accomplished by tuning the oscillators along the three edges of the array. The dynamic behavior of the arrays is studied via a continuum model and the results compared with those of a full nonlinear discrete analysis and a linearized discrete model.