摘要 :
The purpose of the study is to investigate the transient behavior of various radiating elements used in radar phased array systems such as the dipole,the loop,the log-periodic,the slot,the horn,and the spiral antennas. Both the dr...
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The purpose of the study is to investigate the transient behavior of various radiating elements used in radar phased array systems such as the dipole,the loop,the log-periodic,the slot,the horn,and the spiral antennas. Both the driving point impulse response and the step modulated response in the far field are evaluated experimentally and theoretically. (Author)
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摘要 :
Generally speaking, many photonic engineers, while working in a systems development mode, still focus on presenting the unique physical details of the optical elements, instead of using functional representation to describe the s...
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Generally speaking, many photonic engineers, while working in a systems development mode, still focus on presenting the unique physical details of the optical elements, instead of using functional representation to describe the system. The purpose of this presentation is to introduce symbols that can be used to represent the functional intent of most of the phased array architecture.
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摘要 :
The radiation-phase-pattern of a phased array element was measured to assess performance when used in an array requiring a non-planar phasefront. The E- and H-plane element-phase-patterns were found to give constant phase for scan...
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The radiation-phase-pattern of a phased array element was measured to assess performance when used in an array requiring a non-planar phasefront. The E- and H-plane element-phase-patterns were found to give constant phase for scan-angles exceeding 60 deg., but the phase centers were displaced from each other. This separation has to be taken into account when calculating required phase settings for non-planar aperture excitations.
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摘要 :
Some years ago it was proposed that an array of electronic oscillators coupled to nearest neighbors can be made to mutually injection lock and oscillate as an ensemble thus implementing spatial power combining.
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This document presents graphical investigations of the array factor of phased arrays with digital phase shifters. A software program based on basic antenna array theory has been developed in Matlab to obtain the main array charact...
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This document presents graphical investigations of the array factor of phased arrays with digital phase shifters. A software program based on basic antenna array theory has been developed in Matlab to obtain the main array characteristics (array factor and directivity). The array factors of linear arrays of different sizes with different types of phase shifters have been studied as a function of the number of bits and the frequency. Unconventional two-dimensional colour graphical representations are used to identify some characteristics of the array factor of arrays with digital phase shifters that can not be so clearly and quickly visualised with conventional graphical representations. Particularly, the effects of quantisation on the array factor for arrays of different sizes and for phase shifters with different numbers of bits, over scanning and frequency ranges, are shown using this representation. Numerous data are also provided.
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摘要 :
One of the most important problems to be overcome in implementing conformal arrays is controlling the element phases for beam steering. A simplified approximate technique for controlling steering phases of conformal arrays on a ge...
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One of the most important problems to be overcome in implementing conformal arrays is controlling the element phases for beam steering. A simplified approximate technique for controlling steering phases of conformal arrays on a general surface was developed. The technique is to divide the array into several subarrays and to judiciously locate the elements on the curved surface so that the conventional row -- column phase setting can be used in each subarray. Because of the approximate nature of the technique, some phase errors are introduced. However, for a given array size and shape of the conformal surface, the number of subarrays can be chosen such that phase errors are within a specified limit. Analytical and computed results are presented for the techniques application to arrays on circular and parabolic curves. The results show that in many practical cases the approximate technique can be used with negligible degradation in performance.
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