| With the development of the phased array radar technology, whether the radar or the electronic warfare systems require a large phased array antenna with spatial coverage, wide-angle scanning to improve their combat capabilities and scope.The antenna unit is an integral part of the phased array, whose performance directly affects the arrays'. The design of the unit is an essential part of the developing of the phased array radar. So designing a unit that meets the technical requirements of the array is a first and foremost task.For wide-angle scanning phased array antenna, the wide beam feature of the unit is the prerequisite for wide-angle scanning of the phased array.Under this requirement, after in-depth study the two main factors- the mutual coupling between array elements and limited radiation of the antenna unit itself-that affect the scan angle in phased array, this paper started from the thought of change radiation pattern of the antenna unit, a pattern reconfigurable dual-angular antenna based on PIN switches is figured out. There are three different forms of the antenna structure by controlling the switch-off state of the PIN switches: I. only the horizontal direction dipole is feed; II. the horizontal dipole and the normal dipole is connected as two pairs of angular antenna by the PIN switches in the way of lower right to upper left and the feed is in horizontal direction; III. the horizontal dipole and the normal dipole is connected as two pairs of angular antenna by the PIN switches in the way of upper right to lower left and the feed is in horizontal direction. Three patterns would be reconstructed under the three switching control modes. The antenna unit can achieve a large scanning range with high gain of 7dB under the scanning, the 3dB beam-width of the E plane pattern is above 120 degrees, and the 3dB beam-width of the H plane pattern is 115.3 degrees, which meet the potential of the wide-angle scanning in the application of the phased-array antenna.The reconfigurable pattern antenna is also reconstrued by the way of plasma, the simulation results demonstrated that the plasma antenna under three modes is also can achieve the wide-angle reconfigurable feature like the metal antenna. The 3dB beam-width of the E plane pattern is above 120 degrees, and the 3dB beam-width of the H plane pattern is 113.3 degrees. Besides, it avoids the electromagnetic compatibility and DC bias problem of the introduction of the 6 tuning switches in metal antenna. And it is more conducive to miniaturization of the antenna due to that the size of the plasma antenna is 8% smaller than the metal antenna. Last but not the least, it is easy for the plasma antenna to achieve frequency reconfigurablity for the antenna length can be easily controlled, which not like metal one has to tune it by switch. Constantly switching frequency has a very important value to the interference, and other confidential communication. To some extent, plasma is an ideal way to realize the reconfigurable antenna.Plasma is an ideal way to realize reconfigurable antenna, however, in agility, conventional plasma antenna is inferior to the all-optical plasma antena. All-optical plasma antena is that the generation of plasma excitation and maintenance are based on light. So it needs a high-frequency high-voltage pulse excitation source to make the DBD discharge which is a core component to maintain the excitation of the plasma, and the realization of the high-frequency high-voltage pulse generator is depending on the transmission line pulse transformer (TLT) to boost the voltage in high-frequency, so the TLT is a key component in realization of the whole plasma antenna system.This paper is focus on this key component, systematically studied the TLT theory, full analyzed the traditional TLT voltage gain formula and found some problems existed in the formula and the general formula does not facilitate the application of engineering practice, so the discrete voltage gain equation of the 2 to 10 stage for the TLT research is given. Besides, detailed cased is studied, which not only confirms the correctness of the voltage gain equation, but also expressly demonstrated the relationship of the order, gain and impedance ratio. These had never had in the traditional TLT theory but have important practical significance. Finally, experiments are also carried out. The results improved the correctness of the theory of voltage gain. In addition, the study of TLT, we not only take into account the voltage gain problem, but also take into account the current issue, which had not taken into account in the tradition research of the TLT. How to well balance the two as far as possible while improving the secondary line impedance to minimize stray capacitance, this paper has also done a related work from the view of coupling theory and feedback mechanisms, which laid a solid foundation to the future work of the ten stages TLT's research. |
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