Sharif Digital Repository

A new broadband frequency discriminator is introduced for demodulating the frequency modulated signals in the microwave frequency range. Direct demodulation with no need for tuning the center frequency of the resonance circuits is the most important advantage of the proposed technique. This technique uses the in-phase/quadrature demodulation, in some manner, without using any additional local oscillator for down conversion. Simulation of the proposed demodulator has been done with Advanced Design System software to evaluate and predict the system behavior. A setup based on the proposed method was designed and implemented in order to verify the accuracy of the theory. We tested the proposed... 

This paper presents application of high-Q cavity resonator in phase-shifter less technique. A mathematical analysis is presented to show the dependency of the measured phase noise in terms of loaded quality factor and resonance frequency of the high-Q cavity resonator. Experimental measurements resulted from different methods for a synthesized oscillator at 9.976 GHz show great validity and accuracy of the proposed technique. This technique needs no tuning for the phase-shifter and can introduce better sensitivity compared to the setup that uses a delay-line as a frequency discriminator element due to much lower insertion loss particularly at high carrier frequencies. The sensitivity of -113... 

In this paper, a modified method based on the frequency discriminator technique for measuring phase noise of microwave oscillators is presented. In the proposed method, the phase shifter is omitted. In contrast, a 90° hybrid with one more channel containing a phase detector, and a low-noise amplifier is added to the measurement setup. It can be said that an in-phase/quadrature phase-noise detection has been developed. With the proposed method, tuning of the variable phase shifter is not needed anymore. Therefore, the measurement is done automatically, and as a result, the measurement time is decreased. Another considerable advantage of this method is that the method is theoretically... 

The general goal of the facility layout problem is to arrange a given number of facilities to minimize the total cost associated with the known or projected interactions between them. One of the special classes of the facility layout problem is the Single Row Facility Layout Problem (SRFLP), which consists of finding an optimal linear placement of rectangular facilities with varying dimensions on a straight line. This paper first presents and proves a theorem to find the optimal solution of a special case of SRFLP. The results obtained by this theorem prove to be very useful in reducing the computational efforts when a new algorithm based on tabu search for the SRFLP is proposed in this... 

In this paper, we have discussed the results of sensitivity analysis in a payoff matrix of the Matching Pennies game. After representing the game as a LP model, the sensitivity analysis of the elements of the payoff matrix is presented. The game value and the optimal strategies for different values of parameters are determined and compared  

In this paper a new method for measuring phase noise of microwave oscillators based on delay line frequency discriminator is proposed. Elimination of phase shifter is the major advantage of this technique over the traditional delay line technique. By using this new technique, manual or electronic tuning of phase shifter to reach phase quadrature at the phase detector input ports is not needed anymore. A 90-degree hybrid is used in this technique and another path including a phase detector and LNA is added. Finally by using a dual channel FFT analyzer and performing some processing over the sampled data of the two channels, the phase noise of the oscillator will be extracted. A setup based on... 

Inherent properties of UWB signals prevent both coherent and noncoherent processing with conventional methods used in narrow-band RADARs. In this paper, we show how to exploit the Hough transform, first developed to detect lines in an image distorted by noise, to detect moving objects from successive scans that are corrupted by noise and clutter. We discuss why conventional methods fail to process UWB pulses noncoherently/coherently and investigate different aspects of using the Hough transform in noncoherent integration of UWB signals. Simulation results to support our approach are also presented. © 2008 EuMA  

By locating a steel shear panel on the intersection point of the X-braces, concentrically or eccentrically braced shear panel (CBFSP or EBFSP) is formed. In this paper, to perform parametric study, 1-story CBFSP and EBFSP models with span length greater or less than height are considered. Using linear static analyses, the effects of size and location of the shear panel on the lateral stiffness of the frame with respect to the moment resisting frame with the same member sections are investigated. Next, for 1- And 3-story models, maximum displacement, along with base shear, and the ratio between the dissipated energy and input energy are examined under 4 ground motion records. Behavior of the...