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Evaluation of beam steering in circular planar array of coupled microwave oscillators
, Article International Journal of RF and Microwave Computer-Aided Engineering ; Volume 21, Issue 4 , 2011 , Pages 383-391 ; 10964290 (ISSN) ; Banai, A ; Farzaneh, F ; Sharif University of Technology
2011
Abstract
A Green's function to describe the time behavior of the locking phases in a circular planar array of mutually coupled microwave oscillators is proposed. Using this Green's function the dynamic behavior of the array can be described for any arbitrary free running frequency of elements of the oscillator array. Beam steering is realized via detuning the edge oscillators of the array from a reference frequency and the beam direction is controlled by the amount of detuning for each oscillator at the edge. Some detuning functions such as sinusoidal, triangular and rectangular ones have been applied and, the resulting array patterns are compared with one another
Beam Steering in Circular Planar Array of Coupled Microwave Oscillators
, M.Sc. Thesis Sharif University of Technology ; Banai, Ali (Supervisor)
Abstract
In this thesis, it is shown that by detuning the array peripheral elements, without using phase shifters, and locking the array to the common frequency there exists a phase difference between two adjacent elements which is constant along the array and is proportional to the amount of free running frequency detuning. By changing free running frequency and therefore resultant phase difference, one can control the array beam direction. Linear, ring, hexagonal and triangular array configurations have been analyzed so far. In this work we endeavor to explore a circular planar array with weak coupling. The aim is to yield an analytical relationship to determine the free running frequency of each...
Analysis of Resonant Mode Distributions and Suppression of Undesired Modes at Strongly Coupled Oscillator Arrays
, M.Sc. Thesis Sharif University of Technology ; Banai, Ali (Supervisor)
Abstract
Mutually coupled oscillator arrays may be used for power combining at the millimeter-wave region. In addition, these arrays have the capability of beam steering without the use of any phase shifter. Using the strong coupling method is inevitable to obtain synchronization between all elements in the large arrays. One of the challenges in strongly coupled oscillators is the multi-moding problem or oscillation at undesired frequencies. In this thesis, we obtain mode distributions in a one-dimensional and a two-dimensional array with rectangular boundary, using a method based on circuit equations in the frequency domain. Then, we compared the results with the previous works and also verified...
Analytical mode distributions and resonant frequencies in ladder networks used in power combining oscillator arrays
, Article Scientia Iranica ; Volume 15, Issue 2 , 2008 , Pages 175-181 ; 10263098 (ISSN) ; Banai, A ; Farzaneh, F ; Sharif University of Technology
Sharif University of Technology
2008
Abstract
An analysis of resonant modes in ladder networks is performed using difference equations. Linear and loop configurations are studied and analytical relations are derived for the mode distributions and resonant frequencies of these networks, having arbitrary elements. Furthermore, it is shown that a) Modes with an exponential distribution along network nodes may exist in some cases and b) The mode distributions in loop networks are independent of network elements. Finally, a simple criterion is obtained for a loop structure to control the spacing between resonant frequencies. © Sharif University of Technology, April 2008
Various coupling configurations on the performance of two-dimensional coupled oscillator arrays
, Article IET Microwaves, Antennas and Propagation ; Volume 11, Issue 3 , 2017 , Pages 426-432 ; 17518725 (ISSN) ; Banai, A ; Sharif University of Technology
Institution of Engineering and Technology
2017
Abstract
Coupled oscillator arrays (COAs) can be used to control the phase distribution across the aperture of an array antenna in such a manner as to affect steering of the beam without the use of phase shifters. Given the various possible planar configurations of COAs, a systematic design approach is necessary. In this study, the authors present a comprehensive comparison of various configurations of planar COAs based on their sensitivity to random errors in their free running frequencies. The parameters considered are (a) the beam pointing error of the array, (b) the locking probability, (c) the side lobe level, and (d) the beam width of the radiation pattern. These results can serve as a design...
Error Analysis of Electronic Beam Steering in Coupled Oscillator Arrays
, M.Sc. Thesis Sharif University of Technology ; Banayi, Ali (Supervisor)
Abstract
Mutually coupled oscillator arrays have been considered. Detuning of free running frequencies of perimeter elements has been used in these arrays in order to steer the beam without phase shifters. Characteristic equations of transient and steady-state conditions of amplitude and phase of the elements of coupled oscillator arrays has been derived. Literature review is done in coupled oscillator arrays. Sensitivity analysis of beam pointing angle due to free running frequencies of elements in coupled oscillator arrays has been done and the various planar arrays has been compared. Sensitivity analysis of beam pointing angle due to phase error of elements in conventional phased array antennas...