This work develops an adaptive sigma–delta modulator that is based on adapting the quantizer step-size using estimates of the quantizer input rather than the modulator input. The adaptive modulator with a first-order noise shaping filter is shown to be bounded-input bounded-output stable. Moreover, an analytical expression for the signal-to-noise ratio is derived, and it is shown to be independ...

A novel structure of a resonator type guided-wave electrooptic intensity modulator is introduced that uses a higher-order harmonic resonant electrode of coupled microstrip lines combined with polarizationreversed structure. The light modulation cancellation caused by the light transit-time effect in the resonant electrode, which is longer than the wavelength of the standing wave, is compensated...

The excess loop delay in continuous-time LC-based SD modulators, which usually has negative effect on the stability and the signal-tonoise ratio of the modulator, can be used to simplify the modulator architecture and reduce the number of needed feedback branches. The proposed technique is discussed and validated using a design example of a fourth-order bandpass continuous-time LC-based modulator.

In this paper, we propose and study an adaptive delta modulator that has improved SNR performance and better robustness in tracking highly varying signals. The step-size adaptation used in this modulator is based on information about the absolute value of the quantizer input. The modulator is shown to be free of zero-input limit cycles and is BIBO stable.

Previously, the guanylate cyclase activity of Tetrahymena pyriformis was shown to be activated by an endogenous modulator (calmodulin)-like protein (Na-gao, S., Suzuki, Y., Watanabe, Y., and Nozawa, Y. (1979) Biochem. Biophys. Res. Commun. 90, 261-268). This protein has now been identified as the modulator protein. The identification was based on the capability of this protein to activate the b...

An electric optical modulator including a 1 2 multimode interference (MMI) coupler and an integrated Mach–Zehnder Interferometer (MZI) modulator that consists of a microring and a Phase Modulator (PM) is suggested in this paper. Such a modulator can achieve large output RF gain and high linearity performance at the same time. Moreover, due to the application of MMI coupler, traditional direct c...

-In this paper a two dimensional chaotic modulator is proposed, based on an electronic controlled Colpitts Oscillator. The modulator is capable of producing constellations of distinct chaotic patterns in a bifurcation diagram, by creating pairs of specific characteristic values. Key-Words: Chaos, Colpitts Oscillator, Modulator, Voltage Controled Oscilator.

In this paper we have successfully demonstrated a z-propagating Zn-indiffused lithium niobate electro-optic modulator used for optical heterodyne interferometry. Compared to a commercial buck-type electro-optic modulator, the proposed waveguide-type modulator has a lower driving voltage and smaller phase variation while measuring visible wavelengths of 532 nm and 632.8 nm. We also demonstrate a...

In previous work [ 11, we have proposed an adaptive sigma delta modulator with improved dynamic range. The modulator adapts the step-size of the quantizer from estimates of the quantizer input. In this paper, we conduct a stability analysis of the new modulator.

The technology involves a new type of compact device based on magneto-optics in a fiber micro modulator. This type of modulator allows the user to inter manipulate and control the propagation of the incoming light. The operation mechanism uses external magnetic field to manipulate Fe micro particle in order to cause modulation of an optical signal that propagates along an optical waveguide. Thi...