| HF radar is widely used in military and civilian, HF radar research has beengrowing in importance, however, the operating frequency is relatively low,corresponding to the relatively long wavelength, the size of the antenna will berelatively large, in order to ensure that the actual application of the angularresolution and signal to noise ratio requirements, according to the traditional designmethod, the size of a conventional array is often very large, even up to ten thousandmeters. Therefore, the miniaturization of HF radar design has very importantsignificance. After a limited array aperture compact design, accordingly, the widthof the main lobe is pretty wide, by using general beamforming methods can notachieve the same resolution compare with traditional regular arrays,super-resolution algorithms are needed to estimate angles. In this paper, an array ofminiaturized design of key technologies were discussed and analyzed.Firstly, the array antenna theory, a mathematical model of the array signalprocessing, introduced the broadband matching network design, intelligentoptimization algorithms, super-resolution algorithm, as discussed later laid atheoretical foundation.When the case of the array antenna noise ratio factor to meet certain conditions,to ensure that external noise dominant array signal conditions (external noise ismuch larger than the internal noise). External noise under the same conditions, thehigher the efficiency of the antenna unit, the noise factor can reach lower than thelower limit, the smaller the size of the array may therefore improve the efficiency ofthe receiving array element array has a very compact design is important meaning.Design of an antenna matching network is an important way to improve theefficiency of the array element having the array of small importance for design. Forhigh-frequency radar operating frequency, the need to design a broadband matchingnetwork, using real frequency method and genetic algorithm and particle swarmalgorithm combining methods from the use of the intelligent optimizationalgorithms of global search capability makes up for the shortcomings of the realfrequency method. Meanwhile, according to match the needs of differentfrequencies segmented design, the results show that this method can effectivelydesign a matching network for antenna miniaturization design foundation.Receiving antenna compared to the general, a directional antenna can beobtained over a greater directivity in the same aperture, or with a smaller pore sizeto obtain the same directivity. Applications for ultra-miniaturized directionalreceiving array array has a very important significance. Meanwhile, in order to meet the conditions of external noise dominated necessary to add noise ratio constraints,and based on the actual demand for sidelobe pattern of the array is required, theneed for sidelobe control. Select the end-fire array and circular array as an array ofminiaturized receiver array unit, ultra-directional synthesis, simulation analysis todetermine the appropriate size of the array as an array parameter receiving unit.To meet the system requirements for the resolving power of the angle of theresolving power of a conventional planar array is discussed using conventionalplanar array of capabilities as a standard resolution, using super-resolutionalgorithm uses the angle size of the receive array is estimated using the arraywithout grating lobes conditions determine the array element spacing, determine thenumber of array elements at different SNR to achieve the same resolving power canbe miniaturized size of the receiving array with conventional array comparison, thesize of the array has been greatly reduced, proved an array of small the effectivenessof the design... |
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