We analyze a frequency decrease as well as a frequency transition with a temperature increase in the Hodgkin-Huxley (HH) oscillator undergoing saddle homoclinic bifurcations. A gradient of frequency for temperature is derived by perturbation analysis of the stable HH oscillators, in combination with the other gradient of frequency for input current and a so-called phase response curve (PRC) mul...

Driving mode of MEMS (Micro-Electro-Mechanical Systems) Vibratory Gyroscope is discussed in the paper. We analyze the closed-loop circuit of MEMS gyroscope from two aspects of amplitude fixed and frequency locking. In the amplitude fixed circuit, Automatic Gain Control (AGC) circuit is employed to update the amplitude of the driving force, together with a PI controller to improve the accuracy a...

Based on the daily precipitation data from 53 meteorological stations, 11 extreme precipitation indices were selected, categorized and calculated; the temporal and spatial patterns in these indices and their teleconnections with the large-scale circulations were analyzed by the non-parametric Mann-Kendall test; and Sen’s slope estimator and linear regression for the period of 1960–2014 were cal...

This paper presents the design of a compact third-order sinusoidal oscillator based on an operational transresistance amplifier (OTRA). The proposed circuit consists of a single OTRA combined with three resistors and three capacitors. A review of relevant literature revealed that this is the first study to design a third-order sinusoidal oscillator, constructed with a single OTRA and the minima...

We actively stabilize the harmonic oscillation frequency of a laser-cooled atomic ion confined in a radiofrequency (rf) Paul trap by sampling and rectifying the high voltage rf applied to the trap electrodes. We are able to stabilize the 1 MHz atomic oscillation frequency to be better than 10 Hz or 10 ppm. This represents a suppression of ambient noise on the rf circuit by 34 dB. This technique...

The current-mode quadrature oscillators using 2 current controlled current differencing transconductance amplifiers (CCCDTAs) and 2 grounded capacitors are presented. The proposed oscillators can provide 2 sinusoidal output currents with 90o phase difference. The oscillation condition and oscillation frequency can be electronically/independently controlled by adjusting the bias current of the C...

This article presents new current-mode oscillator circuits using CDTAs which is designed from block diagram. The proposed circuits consist of two CDTAs and two grounded capacitors. The condition of oscillation and the frequency of oscillation can be adjusted by electronic method. The circuits have high output impedance and use only grounded capacitors without any external resistor which is very...

A realization of a current-controlled current-mode four-phase quadrature oscillator based on current differencing transconductance amplifiers (CDTAs) is proposed. The proposed oscillator circuit employs only three CDTAs and two grounded capacitors, which can provide four high output impedance sinusoidal current outputs with four-phase difference. The oscillation condition and oscillation freque...