23,929 research outputs found
Nonlinear analog-to-digital converter Patent
Describing continuous analog to digital converter with parallel digital output and nonlinear feedbac
High efficiency multivibrator Patent
Improved semiconductor multivibrator circuit which approaches 100 percent efficienc
Continuous Fourier transform method and apparatus
An input analog signal to be frequency analyzed is separated into N number of simultaneous analog signal components each identical to the original but delayed relative to the original by a successively larger time delay. The separated and delayed analog components are combined together in a suitable number of adders and attenuators in accordance with at least one component product of the continuous Fourier transform and analog signal matrices to separate the analog input signal into at least one of its continuous analog frequency components of bandwidth 1/N times the bandwidth of the original input signal. The original analog input signal can be reconstituted by combining the separate analog frequency components in accordance with the component products of the continuous Fourier transform and analog frequency component matrices. The continuous Fourier transformation is useful for spectrum analysis, filtering, transfer function synthesis, and communications
Nonlinear feedback reduces analog-to-digital converter error
Nonlinear analog-to-digital converter measures the analog input level and continuously adjusts the digital readout scale sensitivity to effectively increase the accuracy. It is able to acquire more accurate low-level data
Phase quadrature-plural channel data transmission system Patent
Plural channel data transmission system with quadrature modulation and complementary demodulatio
Continuous Fourier transform system
Complex digital computer is not required, only summing amplifiers and attenuators are used for transformation of signal. Continuous transform system may be used for spectrum analysis, filtering, transfer function synthesis, and communications
Attractive and Repulsive Casimir Vacuum Energy with General Boundary Conditions
The infrared behavior of quantum field theories confined in bounded domains
is strongly dependent on the shape and structure of space boundaries. The most
significant physical effect arises in the behaviour of the vacuum energy. The
Casimir energy can be attractive or repulsive depending on the nature of the
boundary. We calculate the vacuum energy for a massless scalar field confined
between two homogeneous parallel plates with the most general type of boundary
conditions depending on four parameters. The analysis provides a powerful
method to identify which boundary conditions generate attractive or repulsive
Casimir forces between the plates. In the interface between both regimes we
find a very interesting family of boundary conditions which do not induce any
type of Casimir force. We also show that the attractive regime holds far beyond
identical boundary conditions for the two plates required by the Kenneth-Klich
theorem and that the strongest attractive Casimir force appears for periodic
boundary conditions whereas the strongest repulsive Casimir force corresponds
to anti-periodic boundary conditions. Most of the analysed boundary conditions
are new and some of them can be physically implemented with metamaterials.Comment: 21 pages, 11 figure
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