Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 17 of 17 for “"Sub-harmonic"”.
-
Dinâmica e controle de caos de um sistema pendular com memória de forma
… using Floquet multipliers. Discussions about sub-harmonic orbits stability and the relation between energy consumption and the controller’s parameters are made. The thermal controller uses the thermomechanical behaviour of the SMA for actuation. The results display the usage possibility of SMA …
-
Modeling of V2 Control with Composite Capacitors and Average Current Mode Control
… electronics field. In current mode control, sub-harmonic oscillation is a common issue, especially for constant frequency current mode control: like peak current mode control, valley current mode control, or average current mode control. Recently V2 control is becoming more and more popular …
-
Small-signal Analysis and Design of Constant-on-time V2 Control for Ceramic Caps
… the conventional V2 control suffers from the sub-harmonic oscillation due to the lagging phase of the capacitor voltage ripple relative to the inductor current ripple. Two solutions to eliminate sub-harmonic oscillations are discussed in [39] and the small-signal models are also derived based …
-
SiGe BiCMOS RF ICs and Components for High Speed Wireless Data Networks
… fabrication, and measurement of a 5--6GHz sub-harmonic direct-conversion-receiver (DCR) front-end, implemented in the IBM 0.5um 5HP SiGe BiCMOS process. The design consists of a fully-differential low-noise amplifier (LNA), a set of quadrature (I and Q)x~2 sub-harmonic mixers, and an LO …
-
Chaotic motions of nonlinearly moored structures
… which characterize the moorings. Periodic, sub-harmonic and chaotic responses are observed for both monochromatic and bichromatic waves. In general, sub-harmonic and chaotic responses were obtained forbichromatic excitation to a greater extent than for monochromatic excitation. Transient …
-
Nonlinear resonance of trapped waves on a plane beach
… explanation of the nonlinear mechanism of sub-harmonic resonance. This type of theory has been extended by Minzoni & Whitham (1977), Rockliff (1978), and Rockliff & Smith (1985), among others. Rockliff also initiated a. theory whereby subharmonic resonance can be achieved by an incident …
-
Terahertz beam-steering imager using a scalable 2D-coupled architecture and multi- functional heterodyne pixels
… GHz local oscillation, 280-GHz-signal receiving, sub-harmonic mixing, and intermediate frequency (IF) signal extraction. Each pixel consumes 10 mW power and achieves a sensitivity of 2.9 pW in simulation. The local oscillator (LO) of the pixel is phase coupled with its neighbors; the whole …
-
Circuit Techniques for Multiple and Wideband Beamforming
… simultaneous spectral and spatial filtering by sub-harmonic injection oscillators is presented. The design avoids using expensive delay elements by many conventional wideband phased array. Different from prior art of channelization which cannot solve beam-squinting issue among the sub-channels, …
-
Modelling and analysis of vibrations in flexible cylinders subjected to internal multiphase and external single-phase flows.
… phenomena of flexible straight cylinders subjected to internal two-phase slug flows and external vortex-induced vibrations (VIV) by taking into account the geometric and hydrodynamic nonlinearities. Flow-induced vibration (FIV) is a common phenomenon observed in various engineering systems …
-
5-6 GHz RFIC Front-End Components in Silicon Germanium HBT Technology
… noise amplifier (LNA) and a packaged active x2 sub-harmonic mixer (SHM) have been designed, simulated and measured. The fabrication of the Rifts was through the IBM SiGe foundry; the packaging was performed by RF Micro devices. The mixer and LNA designs were fabricated on separate die, packaged …
-
WEAKLY NONLINEAR DYNAMIC ANALYSIS OF FLOATING BODIES IN WAVES
… occur in the proposed model. 3. In some cases, sub-harmonic motions appear in the nonlinear responses. 4. In the cases with large wave heights, unstable phenomenon occurred which can not be simulated in the linear analysis. From this study, the author thinks that the more reasonable approach …
-
A mechanistic investigation of nonlinear interfacial instabilities leading to slug formation in multiphase flows
… was also adjusted to examine the special case of sub-harmonic resonant interactions which have been observed in many experimental measurements and it was shown that this special case could still effectively create rapid long wave growth with up to bi-exponential growth rates. The second focus area …
-
Wideband and fast THz spectrometer using dual-frequency-comb on CMOS
… structure, which serves as frequency doubler, sub-harmonic mixer and on-chip radiator simultaneously. In particular, theory and design methodology of a dual transmission line feedback scheme are presented, which maximizes the transistor gain near its cut-off frequency fmax. The …
-
Passive Acoustic Mapping of Microbubbles in Focused Ultrasound Induced Brain Therapies for Preclinical Studies
… cloud activity in a vessel-mimicking phantom at sub-, ultra-, and second-harmonic frequencies with high transmit precision. Preliminary in vivo work demonstrated feasibility of this array in inducing localized BBB permeability changes with 3D sub-harmonic MB passive acoustic mapping feedback …
-
Droplet behavior on superhydrophobic surfaces: Interfaces, interactions, and transport
… frequency, the droplet oscillation exhibits sub-harmonic oscillation at half the forcing frequency. ^ The remaining part of the thesis focuses on the design, fabrication and characterization of superhydrophobic surfaces, and droplet behavior on such surfaces. A simple yet highly effective …
-
Equivalent Circuit Model for Current Mode Controls and Its Extensions
… control without any low pass filter, high order harmonics play important role in the feedback control. This is the reason for the difficulty in obtaining the small-signal model for current-mode control in the frequency domain. A continuous time domain model was recently proposed as a successful …
-
Digital enhancement techniques for fractional-N frequency synthesizers
… time-amplifier based TDC (TA-TDC) to achieve sub 1ps resolution. Fabricated in 65nm CMOS process, the prototype PLL achieves better than -106dBc/Hz in-band noise and 3MHz PLL bandwidth at 4.5GHz output frequency using 50MHz reference. The PLL achieves excellent jitter performance of 490fsrms, …