摘要:

Two new phenomena, (i) the considerable dependence of the one-port equivalent impedance, represented by an injection-locked self-oscillating system at the locking frequency (within the locking bandwidth), on the external low-frequency signals and (ii) the frequency conversion with a lower-sideband signal gain and an upper-sideband signal suppression using injection-locked oscillator are examined. The paper shows that the manifestation mechanism of such phenomena is parameteric. The explanation lies in the reversibility of the modulation-parametric interactions in perturbing nonlinear self-oscillating systems and in the influence of the second harmonic of the time-varying injection-locked oscillator impedance. An original method of investigation for modulating-parametric and conversion phenomena in perturbing nonlinear self-oscillating systems has been developed, based on the perturbation theory and the method of Samoylo and Spasov. The analytically and experimentally established relations between the components of the low-frequency impedance and the transmission impedance of frequency conversion of a negative-resistance injection-locked oscillator and the locking frequency have been derived.

DOI:10.1049/ip-g-1.1984.0001

出版商:IEE    

年代:1984

数据来源: IET

摘要:

In the variable-phase-shift automatic voltage regulator, the output is sampled at half-cycle intervals, and compared to a reference. The error is applied to a phase control circuit and filter, whose output is a sinusoid of constant amplitude, at mains frequency, but variable phase. This is amplified by a class B power amplifier, and added to the mains line voltage in such a sense as to correct it. Theoretical, simulation and experimental results are given to demonstrate the high accuracy (of the order of 0.2%), very fast response (between one half and one cycle) and low distortion of the device.

DOI:10.1049/ip-g-1.1984.0003

出版商:IEE    

年代:1984

数据来源: IET

摘要:

The hardware implementation of a sixth-order wave digital filter on a single printed-circuit board has been described in the literature. In the present paper, a greatly improved hardware design is discussed. By including more parallelism into the architecture, sampling rates of over 500 kHz can be achieved for a fifthorder filter. With the aid of a microprocessor development system, the filter can be programmed for any order up to 15. Once programmed, the filter runs independently. An example is given, which illustrates the hardware performance with various coefficient wordlengths. Attention is also paid to the question of in-band noise.

DOI:10.1049/ip-g-1.1984.0004

出版商:IEE    

年代:1984

数据来源: IET

摘要:

Nonlinear resonance and parametric phenomena in an oscillating circuit with two nonlinear opposite reactive elements and negative resistance are presented. The examination has been performed on the basis of a nonlinear oscillating circuit represented by a two-transistor model of apnpn-type device with nonlinear inductance and negative resistance and a self biaspnjunction with nonlinear capacitance and a nonlinear conductance.

DOI:10.1049/ip-g-1.1984.0005

出版商:IEE    

年代:1984

数据来源: IET

摘要:

A method is described for encoding the residual speech signal in residual-excited linear predictive coders. In this method, a low-sequency baseband of the residual is transmitted by encoding the coefficients of the lower half of the Walsh spectrum. Techniques for reconstructing the upper portion of the spectrum are discussed. The resulting algorithms are simple to implement and simulation studies have shown that a bit rate of 10 kbits−1can be achieved.

DOI:10.1049/ip-g-1.1984.0006

出版商:IEE    

年代:1984

数据来源: IET

摘要:

A nonlinear sensitivity criterion is defined for the single-loop feedback circuits in terms of the Volterra-Wiener series. It is shown that, when the input-signal amplitude is sufficiently small, this sensitivity approaches the linear definition for the change in amplifier gain. The result is applied to a single-amplifier filter whose dynamic range is limited by slew-induced distortion. It is demonstrated that, for such circuits, the nonlinear sensitivity is closely related to the gain-sensitivity product.

DOI:10.1049/ip-g-1.1984.0007

出版商:IEE    

年代:1984

数据来源: IET