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In this paper, a wide tuning-range CMOS voltage-controlled oscillator (VCO) with high output power using an active inductor circuit is presented. In this VCO design, the coarse frequency is achieved by tuning the integrated active inductor. The circuit has been simulated using a 0.18-µm CMOS fabrication process and presents output frequency range from 100 MHz to 2.5 GHz, resulting in a tuning range of 96%. The phase noise is –85 dBc/Hz at a 1 MHz frequency offset. The output power is from –3 dBm at 2.55 GHz to +14 dBm at 167 MHz. The active inductor power dissipation is 6.5 mW and the total power consumption is 16.27 mW when operating on a 1.8 V supply voltage. By comparing this active inductor architecture VCO with general VCO topology, the result shows that this topology, which employs the proposed active inductor, produces a better performance. [ABSTRACT FROM PUBLISHER]

The paper describes a method for the numerical study of the growth of current in circuits which comprise a non-linear inductor. The non-linear magnetization curve is supposed to be composed of a number of linear chords and an analytical expression for current is developed for each chord. Computation of current over any chord at equally spaced points along the time axis is carried out until the difference of the magnitude of this current and that at the end of the chord is the minimum. The method of solution has been explained taking the numerical illustration of the field circuit of a generator where the impressed potential difference is constant, the solution being obtained with the help of a digital computer. The graph showing the nature of the build-up of current is in perfect agreement with experimental data. The method has also been extended to circuits where the impressed voltage is alternating as in the case of an iron core transformer. [ABSTRACT FROM AUTHOR]

A circuit for realizing floating inductance, grounded to a floating admittance converter, floating frequency dependent negative resistance (FDNR) and floating capacitance simulators depending on the passive element selection is presented. The proposed circuit employs only grounded passive elements and second-generation current conveyors (CCIIs) but it requires single passive component matching. Replacing second-generation current controlled conveyors (CCCIIs) instead of the CCIIs in the developed circuit, an electronically tunable floating inductor with bias currents can be obtained. Also, replacing dual X second-generation current conveyors (DXCCIIs) instead of the CCIIs in the introduced circuit, an electronically tunable floating inductor with bias voltages can be obtained. Under non-ideality conditions, the proposed circuit can realize a lossless floating inductor and a capacitor depending on the passive element choice. Simulation results using SPICE program are given to verify the theory. [ABSTRACT FROM AUTHOR]

A McMurray commutation circuit with a (di/dt) inductor in series with the main thyristors is analysed. Analysis shows that advanced firing on the commutation current ring is necessary in order to avoid the commutation failure in case of sudden loading of the inverter. Advanced firing boosts the commutation capacitor voltage. Hence, the operating conditions should be adjusted so as to control the commutation capacitor voltage in a narrow range from no-load to full-load conditions. At the same time, the commutation energy corresponding to these conditions should not deviate much from the minimum commutation energy. [ABSTRACT FROM AUTHOR]