| The critical method to maintain national security in the fifth domain of warfare,after land,sea,air and space,is electromagnetic interference,among which radar interference is an important part.On the background of airborne platform,the integrated device radiating radar interference signals with the power combination of active phased-array is designed in the form of the kernel electrical function layer in‘smart skins'.It is of great practical significance to national defense construction.The concept and innovation point of the design are listed as follow.1.There are strict restrictions to space,weight and energy consumption in the aircraft especially the UAV(unmanned aerial vehicle).As a result,the power of centralized transmitter is also restricted.As a solution to this,the device is designed with active phased-array,which can not only decrease system consumption while meeting the power needs in radar interference by spatial power combination,but also focus the energy on a particular direction or area with flexible beam control to improve the effects of interference.According to relevant information abroad,interference device of the next generation has initial developed and wideband phased array is a critical part.Technique and theory of wideband phased array are used as reference in the design,which is applied based on the characteristics and demands of radar interference device.2.The structure with synchronous clock tree and power driver group of which phase can be shifted is built.Power drivers and antenna array elements are paired together to form the active phase array elements.Elements use clock generated by synchronous clock tree as reference and numerical control to modulate phase independently.The design has simple structure.It can be controlled flexibly and expanded easily.To meet the request of combined power and beam form,only the deflection of synchronous clock tree should be controlled.The device avoid that the request power of centralized transmitter is high and the problem in power distributing and phase shifting.It also reduce the path loss and meet the request of the interference power and beam modulation.3.One type of super-miniature wideband RF antenna stimulation sub-module,whose phase and amplitude can be controlled is designed.Its frequency range is 150MHz~4.4GHz.it can control the phase of reference clock with 12bit and the phase of 360°,at the accuracy of 4096.The control accuracy of power is 0.5dB.The dynamic range is 24.5dB.The linear output power is 0.5W(27dBm).Saturated output is 1W(30dBm).Shield and RF circuit are designed integral with delicate structure,which is sized as 35mm×35 mm×10mm to be fit for‘smart skins'.4.The engineering realization is figured out with smart skins.Smart skin consists of ultrathin antenna the same size as the platform,transmitter,receiver and beam forming device with super miniature radiation units inside.The electrical and structure characteristics are supreme and it is applied in radar,EW and communication systems.Smart skin is advanced realized technique successfully mixed with design of aircraft structure,composite material,information mixture and electromagnetic compatibility technology.The process of realization is complex system engineering project.The design attempts to combine electronic modulation for smart skins,antenna elements,system construction and physical structure and be realized with high density packaging technology.5.The active phased-array is designed with independent numerical control methods.As a result,it is easy to expand the scale of the array to increase the aperture radiation power obviously as the array being expanded.The area of smart skins will increase with the number of elements and the thickness will stay the same with advanced flat packaging methods.The whole system is made up of micro-strip array,active phased-array simulation group,synchronous clock tree,and auxiliary heat dissipation device in the modulation of phase control and ports.The prototype is built with 4×4 antenna array,2×8 active simulation sub-elements group and smart skins which has an area of 400×300mm~2 and thickness of 15~20mm.It dissipates heat with water.The overall index of the system is as follow.The frequency range is3.8~4.4GHz.The gain of array is 18dB.The consumption of power amplifier is about 32W.Equivalent radiation power with no distortion is 500W(compared with centralized power amplifier with Omni-directional antenna).The efficiency of space power combination is 75%.The subject of the issue refers to the concept of smart skins and phased-array.It is the latest research both in the field of smart skins and active phased-array.The issue has beneficial practical results. |
PDF Full Text Request