Understanding a simple crystal oscillator transmitter circuit The transistor in common emitter configuration contributes -180 deg phase shift between base. Write short notes on (i) RC Oscillator (ii) Wien bridge Oscillator (iii) Crystal It consists of a conventional single transistor amplifier and a RC phase shift network. The wien-bridge oscillator is the standard oscillator circuit for all fr...

In this paper we derive an exact master equation for two coupled quantum harmonic oscillators interacting via bilinear coupling with a common environment at arbitrary temperature made up of many harmonic oscillators with a general spectral density function. We first show a simple derivation based on the observation that the two harmonic oscillator model can be effectively mapped into that of a ...

Chaotic signals must have specific characteristics in order to be used in certain applications. One of them is band-limited power spectrum. An approach to design of chaotic sources with band-limited feature is proposed. Realization of the approach in microwave band is demonstrated.

Electronic feedback is used to self-excite the axial oscillation of a single electron in a Penning trap. Large, stable, easily detected oscillations arise even in an anharmonic potential. Amplitudes are controlled by adjusting the feedback gain, and frequencies can be made nearly independent of amplitude fluctuations. Quantum jump spectroscopy of a perpendicular cyclotron motion reveals the abs...

Molecular mechanisms responsible for 24 h circadian oscillations, entrainment to external cues, encoding of day length and the time-of-day effects have been well studied experimentally. However, it is still debated from the molecular network point of view whether each cell in suprachiasmatic nuclei harbors two molecular oscillators, where one tracks dawn and the other tracks dusk activities. A ...

In this chapter, we take a different approach. In Section 2, we analyze the basics of analog subtractive synthesis, using the simple patch of a square-wave oscillator processed by a low-pass filter with a dynamically variable cutoff frequency. In Section 3, we show how a single mathematical function can model both the oscillator and filter together, and describe an efficient formation for this ...

An oscillatory network of columnar architecture located in 3D spatial lattice was recently designed by the authors as oscillatory model of the brain visual cortex. Single network oscillator is a relaxational neural oscillator with internal dynamics tunable by visual image characteristics - local brightness and elementary bar orientation. It is able to demonstrate either activity state (stable u...

Systems theoretic tools, including mathematical modeling, control theoretic analysis, and feedback design, advance the understanding of the circadian clock: a set of noisy oscillators that communicate to ensure its function as a reliable pacemaker. The clock’s internal time, or phase, is a key performance measure used to investigate dynamics of a single deterministic oscillator for the purpose ...