PLA's new AWACs will be Stealth uniquely worldwide, by a new technological breakthrough with hightech Radar antenna skin over their planes. The external surface (most parts) will be a flexible antenna material that transmits and receives signals efficiently. It's system will choose weather to absorb or transmit signals, when absorbed, it is stealth. When transmitting it is functioning like radar antenna dish.
Chinese news release show a sample photo of their new material developed.
http://mil.news.sina.com.cn/jssd/2018-06-08/doc-ihcscwxa4375145.shtml
中国攻克一项世界顶尖技术 预警机隐身化或将实现
中国攻克一项世界顶尖技术 预警机隐身化或将实现
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近日，中航工业集团直升机所完成了中国首部直升机柔性共形天线的研制，并将在某款新研制的直升机上采用。据相关报导显示，中航工业直升机所对“柔性共型天线”的定位是为了匹配“速度更快、隐身性能更好、可靠性更高”的直升机，由此不少媒体和分析人士认为，“柔性共型天线”的出现是隐身直升机在研的信号。
图为国外厂商展出的共型阵原型，可见其高度贴合于飞行器的蒙皮弧度。
所谓“共型天线”，就是将雷达、通信等设备的天线整合在飞行器机身的蒙皮或蒙皮内。而在此之前，飞行器机身的天线必定要突出于机身外表面或占用关键部位，诸如预警机的“大圆盘”和“平衡木”、战斗机机身外的“刀型通信天线”、乃至于武装直升机的机鼻或旋翼顶的“顶个球”，都是为传统平面雷达天线阵列专设的空间。
这些凸出于流线体机身的天线，毫无疑问会给飞行器增加极大的空气阻力，乃至于大大降低飞行器平台的飞行性能，至于隐身不隐身的问题倒显得不那么重要了。
图为“顶个球”的AH-64D“长弓阿帕奇”。
当然，单用一个“飞行性能损失”的说法显得较为笼统。先以家喻户晓的AH-64D“长弓阿帕奇”武装直升机为例：纵观整个“长弓阿帕奇“，我们不难发现其旋翼轴顶的相控阵雷达几乎游离于整个机身（包括旋翼）之外，因此该部分的结构强度相当有限，可以说是整架武装直升机强度上的“短板”所在，也正是“长弓阿帕奇”最大容许过载的命门。
换句话说，若能将这部分天线整合在机身内部，“长弓阿帕奇”便可以在战场上做更加复杂和随心所欲的机动，不再受薄弱的天线结构限制。
图为展开平板雷达天线的卡-31舰载预警直升机。
另一个很典型的例子则是苏/俄设计和制造的卡-31舰载预警直升机，其预警雷达天线为折叠式，不用时能够贴合在平坦的机身下方，以减小阻力。
但在展开时，这面巨大的长方形天线就极大地限制了卡-31的飞行速度，甚至还影响到了它的飞行稳定性。
当然，这台E-801雷达的设备位于机身内部，所以若能将天线集成在卡-31机身的蒙皮上，那么它在速度方面的飞行性能就将得到极大改善，雷达启动和转移的时候都能飞出最高速度。
图为运-9平台改造而来的空警-200预警机。机背上的“平衡木”是相控阵雷达的两面天线。
值得一提的是，随着远程主动雷达空空导弹的实用化，原本不必身处战线前沿的预警机也成了战斗机“斩首”的目标，因此预警机的隐身化可谓是势在必行。
但即便机身能够隐藏起来，预警机硕大的“平衡木”或“大圆盘”用吸波涂料还是藏不住的。而在有了共型天线之后，“隐身预警机”也就从不可能变为可能了。
图为诺斯罗普-格鲁曼公司的第六代（国标第五代）战斗机设想图。
相应的，由于探测需求的增加，柔性共型天线和射频管理结合在一起，被认定为是第六代战斗机的标配技术之一：机头尺寸的缩小和雷达天线面积的增大，本质上是矛盾的。因此，下一代战斗机在利用共型天线技术的基础上，可以做到“浑身上下是天线”，极大地改善了机载雷达的辐射性能，同时又为隐身和气动外形的布局设计提供了方便。（利刃/TO）
China has conquered one of the world’s top technology AWACS stealth or will realize
China has conquered one of the world’s top technology AWACS stealth or will realize
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Recently, AVIC Helicopters completed the development of China's first helicopter flexible conformal antenna and will be used on a newly developed helicopter. According to relevant reports, AVIC Helicopter’s positioning of “flexible common antenna” is to match “helicopters with faster speed, better stealth performance and higher reliability”, and many media and analysts believe that “ The emergence of "flexible common antenna" is a signal for stealth helicopters.
The picture shows the prototype of a common-array array exhibited by foreign manufacturers. It can be seen that it is highly fitted to the curvature of the aircraft's skin. The picture shows the prototype of a common-array array exhibited by foreign manufacturers. It can be seen that it is highly fitted to the curvature of the aircraft's skin.
The so-called "conformal antenna" is the integration of radar, communications and other equipment in the aircraft's skin or skin. Before that, the antenna of the aircraft's fuselage must protrude from the outer surface of the fuselage or occupy key parts, such as the "big disk" and "balance beam" of the AWACS, the "knife-type communication antenna" outside the fighter's fuselage, and even The nose of the helicopter gunship or the "top ball" on the top of the rotor is a space reserved for traditional planar radar antenna arrays.
These antennas protruding from the streamlined fuselage will undoubtedly add great air resistance to the aircraft, and even greatly reduce the flight performance of the aircraft platform. As for stealth and non-stealth, it is less important.
The picture shows the "top ball" AH-64D "Longbow Apache." The picture shows the "top ball" AH-64D "Longbow Apache."
Of course, the single use of a "flight performance loss" is more general. Take the example of the well-known AH-64D Longbow Apache helicopter gunship first. Throughout the “Longbow Apache”, we can easily find that the phased-array radar on the top of the rotor shaft is almost free of the entire fuselage ( In addition to rotors, the structural strength of this part is rather limited, which can be said to be the "short board" of the entire armed helicopter, and it is also the life gate of the Longbow Apache that allows maximum overload.
In other words, if this part of the antenna can be integrated inside the fuselage, the "Longbow Apache" can do more complex and arbitrary maneuvers on the battlefield, no longer limited by the weak antenna structure.
The picture shows a card-31 ship-warning helicopter with a flat radar antenna. The picture shows a card-31 ship-warning helicopter with a flat radar antenna.
Another very typical example is the Soviet-Russian-designed and manufactured card-31 carrier-based early-warning helicopter. Its early-warning radar antenna is folded and can fit under a flat fuselage when not in use to reduce resistance.
However, at the time of deployment, this large rectangular antenna greatly limited the flight speed of the Ka-31, and even affected its flight stability.
Of course, the equipment of this E-801 radar is located inside the fuselage, so if the antenna can be integrated into the skin of the Ka-31, then its flight performance in terms of speed will be greatly improved. When you transfer, you can fly the highest speed.
The picture shows the Air Police-200 early warning aircraft transformed from the Win-9 platform. The "balance beam" on the back of the aircraft is the two-sided antenna of the phased array radar. The picture shows the Air Police-200 early warning aircraft transformed from the Win-9 platform. The "balance beam" on the back of the aircraft is the two-sided antenna of the phased array radar.
It is worth mentioning that with the practicalization of long-range active radar air-to-air missiles, the original AWACS that were not at the forefront of the front have also become the target of the fighter's "dagger." Therefore, the concealment of the AWACS can be described as imperative.
But even if the fuselage can be hidden, the large "bombardment beam" or "big disk" of the AEW could not be concealed. With the common antenna, the "stealth early warning machine" has never become possible.
The picture shows the Northrop Grumman's sixth-generation (GB5) fighter plan. The picture shows the Northrop Grumman's sixth-generation (GB5) fighter plan.
Correspondingly, due to the increase in detection requirements, the combination of flexible common antenna and radio frequency management has been recognized as one of the standard technologies of the sixth generation fighter: the reduction of the head size and the increase of the radar antenna area. It is contradictory. Therefore, on the basis of using common antenna technology, the next generation of fighter jets can achieve "beneath the antenna", greatly improving the radiation performance of airborne radar, and at the same time providing convenience for the layout design of stealth and aerodynamic shapes. (Leader/TO)
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