A wide-tunable translinear second-order oscillator

This paper describes the design and measurement of a translinear second-order oscillator. The circuit is a direct implementation of a nonlinear second-order differential equation and follows from a recently developed synthesis method for dynamic translinear circuits. It comprises only two capacitors and a handful of bipolar transistors and can be instantaneously controlled over a very wide frequency range by only one control current, which indicates its suitability for spread-spectrum communications. Its total harmonic distortion can be made small by the design, which enables fully integrated transmitters. A semicustom test chip, fabricated in a standard 2-μm, 7-GHz, bipolar IC process, operates from a single supply voltage, which can be as low as 2 V and oscillates over six decades of frequency with -31 dB total harmonic distortion     

Current controlled oscillator based on translinear conveyors

A current controlled oscillator based on translinear current conveyors is presented. The oscillation frequency can be varied proportionally to the bias current. The oscillator uses two CCCII's, and two grounded capacitors. SPICE simulation results agree with the theory     

Electronically tunable multiphase sinusoidal oscillator using translinear current conveyors

A new electronically tunable current-mode multiphase sinusoidal oscillator based on translinear current conveyors is presented. The proposed oscillator circuit, which employs only one translinear current conveyor and one grounded capacitor for each phase, can generate arbitrary N output current equal-amplitude signals that are equally spaced in phase (N being even or odd), all at high output impedance terminals. The frequency of oscillation and the condition of oscillation can be controlled electronically and independently through the bias current of the translinear current conveyor. The proposed structure also has simple circuitry, low-component count, and is highly suitable for integrated circuit implementation. The theoretical results were verified by PSPICE simulation. In addition, the modification of the N sinusoidal oscillators to construct a programmable multiphase oscillator is also discussed.     

Quadrature oscillator and universal filter based on translinear current conveyors

This paper presents quadrature oscillator and universal filter based on translinear current conveyors. The proposed circuit can realize as a quadrature oscillator or a universal filter without changing the circuit topology. When it works as a quadrature oscillator, four quadrature current outputs and two quadrature voltage outputs can be obtained. The condition and frequency of oscillation of oscillator can be controlled orthogonally and electronically. When it works as a universal filter, low-pass, band-pass, high-stop, band-stop, and all-pass filtering functions can be obtained simultaneously. The natural frequency and quality factor of filters can be controlled orthogonally and electronically. The proposed topology is simulated using PSPICE simulators and experimental results are also used to confirm workability of new circuit.     

A translinear floating current-source with current-control

A current-controlled floating current-source using bipolar junction transistors is proposed. One translinear mixed cell (including PNP and NPN transistors) and four complementary current mirrors have been employed to implement it. Accuracy, wide bandwidth and low distortion are their more important qualities. The characteristics and the properties of the practical realization are presented and discussed.     

Research on the chaotic secure communication of the phase-space symmetric Lorenz oscillator group

To meet the demand of chaotic oscillators for large scale secure communications,the Lorenz oscillator was taken as an example,a phase-space symmetric chaotic oscillator group model was proposed and the synchronization problem was studied.According to the condition of synchronization,a communication model based on symmetric chaotic oscillator was constructed and verified by simulation.The symmetrical oscillator group can provide an infinite number of symmetric chaotic oscillators,which can satisfy the application in large-scale secure communication and maintain the excellent characteristics of the original chaotic oscillator,and has a good application prospect.     

Negative impedance converter with a translinear implementation

A new negative impedance converter circuit, which is a current inversion type (I-NIC), is described. The basic cell consists of a mixed translinear loop comprising two pnp and two npn bipolar transistors. This cell is used in conjunction with a constant current source and two complementary current mirrors. The characteristics and the properties of the practical realization are presented and discussed. A new bandpass filter, which is a current processing circuit, using the I-NIC and a current-controlled current source (CCCS) are also introduced. Experimental results are given.     

A biochemical translinear principle with weak inversion ISFETs

A weak inversion region is shown to exist in ion-sensitive field effect transistor (ISFET) sensors. It is therefore proposed that the ISFET and its chemically sensitive (ChemFET) counterparts be used as translinear elements in the synthesis of novel biochemical input stages which perform real-time mathematical manipulation of biochemical signals. A Biochemical Translinear Principle using weakly inverted ChemFETs is presented. A low-power current-mode input stage circuit is presented as an application of the principle. This yields a linear relation between drain current and hydrogen ion concentration valid over four decades. This paper demonstrates an important and necessary step toward biochemical VLSI.     

Application of the translinear principle in digital circuits

The translinear principle, which is useful in the design of analog integrated circuits, can also be applied to the design of digital integrated circuits. As an example of this technique, a new nonsaturating bistable element is described, which operates according to the translinear principle and which is realizable with standard bipolar integrated circuit processes. The circuit can operate over a wide range of supply current from some milliamperes down to below 1 nA.     

Large signal analysis of the SiGe HBT translinear harmonic mixer

Analytical expressions are obtained for the amplitudes of the desired output components of a SiGe translinear harmonic mixer excited by large-amplitude local oscillator and radio-frequency signals. Comparison with previously published calculated and simulated results is included.     

用Matlab分析Lorenz系统族

用Matlab分析了Lorenz系统族的演化过程,并分析了该系统族中3大典型系统、即Lorenz系统,Chen系统和Lü系统之间类似的定性特征及他们之间的联系。重点展示了Lü系统在该系统族中所起的桥梁作用。     

Hyperchaotic oscillator with gyrators

A fourth-order hyperchaotic oscillator is described. It contains a negative impedance converter, two gyrators, two capacitors and a diode. The dynamics of the oscillator is shown to be characterised by two positive Lyapunov exponents. The performance of the circuit is investigated by means of numerical integration of appropriate differential equations, hardware experiments and PSPICE simulations     

RESEARCH ON THE RELAXATION OSCILLATOR WITH BNRT

A piecewisely linear(with three or four segments)dynamic version for relaxation oscillations in acircuit with bidirectional negative resistance transistor is studied.The circuit and dynamic equation are given andsome properties of the relaxation oscillations are discussed.Experimental results agree well with the computations,showing that the dynamic model is adequate and useful.     

A BJT translinear loop based optoelectronic integrated circuit with variable transimpedance for optical storage systems

A 0.35 μm SiGe BiCMOS optical receiver with voltage-controlled transimpedance is presented. A variable-gain current amplifier using a BJT translinear loop is applied. A transimpedance dynamic range of 1554 (63.8 dB) with the largest transimpedance of 2.84 MΩ, a bandwidth up to 379 MHz, and a transimpedance bandwidth product up to 168 TΩHz are achieved.     

Analogue control of the slew-rate in LIN bus digital transitions using translinear circuits

A novel technique to control the LIN (Local Interconnect Network) bus slew-rate transitions in automotive environment, where large fluctuations of the battery voltage are present, is reported. A bipolar translinear circuit generates a non-linear current that is used to modulate a MOS relaxation oscillator, producing a clock frequency that delivers a constant number of pulses during the LIN bus digital signal transition. This frequency modulated clock when applied to a digitally controlled analogue wave-shape driver results in a LIN bus digital transition with a slew-rate that is constant and independent of the car battery voltage. Experimental results measured in an IC implemented in a BiCMOS process showed that constant slew-rate transition of 1?±?2% V/??s is obtained for battery voltages varying from 6 to 40 V, over the temperature range of ?40 to 150°C.     

Transit-time oscillator with velocity-limited injection

The basic theory of a space-charge transit-time oscillator is outlined in which phase lag of current is caused by using low-velocity injection. Large negative resistances are anticipated at microwave frequencies, giving generation of moderate power levels with low-noise operation. Approximate design calculations for a representative idealised structure 100 ?m square, based on silicon and operating at a frequency of 10 GHz, suggest a negative resistance of ?50 ? and a negative Q factor of -?/2, with a maximum output power of about 1 W and an efficiency of about 7%.     

用HDL语言实现循环冗余校验

文章介绍了用硬件描述语言（HDL）实现循环冗余校验（CRC）的方法。     

Lorenz, Lorentz, and the gauge

Briefly discusses work by L. Lorentz and H.A. Lorentz together with the concept of the Coulomb gauge