This paper mainly introduces the Wideband 5-bit MMIC digital attenuator with high precision. Firstly, the theories of basic GaAs digital attenuator MMIC’s configurations are searched. Secondly, every possible configuration is contrasted, subsequently, appropriate topology is selected for each stage. This attenuator has been realized by 0.5!m GaAs pHEMT process. Simulation results of the digital...

There has been a flourishing prospect of UWB technology in recent years in both communication and other purposes like microwave imaging and radar applications. Recent studies of UWB antenna structures are specially concentrated on microstrip [1], slot and planar monopole antennas [2]. In this work, a small monopole antenna with diamond shape of the patch (30 x 26 mm2) printed microstrip fed mon...

Observation techniques for measuring the vibration of a single microcapsule with a hard plastic shell in an acoustic standing wave field are discussed. First, optical observation of a microcapsule vibration by using a laser Doppler vibrometer (LDV), which can observe small capsule vibration amplitudes at high-frequency, was investigated. Capsules of tens of micrometer size were trapped at the a...

Background: The effects of position and exercise on pulse wave distribution across a healthy, compliant arterial tree are not fully understood. We studied the effects of exercise and position on the pattern of pulse arrival times (PATs) in healthy volunteers. Moreover, we compared the pulse arrival time ratios to the respective distance ratios between different locations. Methods: Thirteen youn...

Mammalian spontaneous otoacoustic emissions (SOAEs) have been suggested to arise by three different mechanisms. The local-oscillator model, dating back to the work of Thomas Gold, supposes that SOAEs arise through the local, autonomous oscillation of some cellular constituent of the organ of Corti (e.g., the "active process" underlying the cochlear amplifier). Two other models, by contrast, bot...

In this paper we show that the sensitivity of absorption imaging of ultracold atoms can be significantly improved by imaging in a standing-wave configuration. We present simulations of single-atom absorption imaging both for a travelling-wave and a standing-wave imaging setup, based on a scattering approach to calculate the optical density of a single atom. We find that the optical density of a...

A nonlinear theory of pattern selection in parametric surface waves (Faraday waves) is presented that is not restricted to small viscous dissipation. By using a multiple scale asymptotic expansion near threshold, a standing wave amplitude equation is derived from the governing equations. The amplitude equation is of gradient form, and the coefficients of the associated Lyapunov function are com...

A nonlinear theory of pattern selection in parametric surface waves (Faraday waves) is presented that is not restricted to small viscous dissipation. By using a multiple scale asymptotic expansion near threshold, a standing wave amplitude equation is derived from the governing equations. The amplitude equation is of gradient form, and the coefficients of the associated Lyapunov function are com...