We have demonstrated and characterized the generation of ultra broadband microwave frequency combs with an optical pulse-injected semiconductor laser. Through optical pulse injection, the microwave frequency combs generated in the slave laser (SL) have bandwidths greater than 20 GHz within a +/-5 dB amplitude variation, which is almost 3-fold of the 7 GHz relaxation oscillation frequency of the...

Measurements of the frequency stability of a far-infrared molecular laser have been made by mixing the harmonic of an ultrastable microwave source with a portion of the laser output signal in a terahertz (THz) Schottky diode balanced mixer. A 3 GHz difference-frequency signal was used in a frequency discriminator circuit to lock the laser to the microwave source. Comparisons of the short- and l...

Experiments have been conducted on a dual electric grid thermionic device to investigate an alternative method of space charge mitigation in a thermionic energy convertor (TEC). Two electric grids, the attractor and deflector grids, provide opposing electric fields to overcome space charge while minimizing power losses to the attractor grid. Electron beams are formed in the electrode gap provid...

Title of Dissertation: SYNTHESIS AND DESIGN OF MICROWAVE WIDEBAND FILTERS AND COMPONENTS Wei Meng, Doctor of Philosophy, 2014 Directed By: Professor Kawthar A. Zaki, Department of Electrical and Computer Engineering In the development of modern communication systems, various stringent requirements are imposed on the hardware components to support emerging applications. There is broad interest i...

Partial discharge (PD) detection is an important method to evaluate the insulation condition of metal-clad apparatus. Non-intrusive sensors which are easy to install and have no interruptions on operation are preferred in onsite PD detection. However, it often lacks of accuracy due to the interferences in PD signals. In this paper a novel PD extraction method that uses frequency analysis and en...

Operation of a spin-torque microwave detector (STMD) in a weak perpendicular bias magnetic field has been studied theoretically. It is shown that in this geometry a novel dynamical regime of STMD operation, characterized by large-angle out-of-plane magnetization precession, can be realized. The excitation of the large-angle precession has threshold character and is possible only for input micro...

Germination is a key process in plants' phenological cycles. Accelerating this process could lead to improvment of the seedling growth as well as the cultivation efficiency. To achieve this, the effect of microwave frequency on the germination of rice seeds was examined. The physiological feedbacks of the MR 219 rice variety in terms of seed germination rate (GR), germination percentage (GP), a...

Microwave absorbing property of composites containing Ag nanoparticles filled multiwalled carbon nanotube buckypaper (Ag-BP) has been investigated. Buckypaper doped with silver was prepared by direct dispersion and filtration method. From the low temperature resistivity measurement it was found that increasing doping level decreases the electrical conductivity of the buckypaper. 30 wt. % and 40...

This paper displays a new access for determining the powerful firing signals for suppression of oscillations by using Optimized PI Based Interline Power Flow Controller [IPFC] through Nonlinear Control Design Block set. The IPFC performance is tested with Proportional Integral Gain [PI] controllers in comparison with Power Oscillation Damping controller [POD] on Modified Phllips-Heffron Model o...