Design of the GIF Antenna Based on Phased-Array Technology Yang Jia, Hong-bin Ren b and Jing-xin Liuc

Transcription

1 5th International Conference on Environment, Materials, Chemistr and Power Electronics (EMCPE 016) Design of the GIF Antenna ased on Phased-Arra Technolog Yang Jia, Hong-bin Ren b and Jing-in Liuc Air and Missile Defense College, Air Force Engineering Universit, Shani Xi an, , China a jiangjs@163.com, b @163.com, cpuma330@16.com Kewords: Fuze, Seeker, Integrated design, Phased-arra antenna. Abstract. The need of antenna design and the basic principle of phased-arra antenna are analsised. Then the rectangular-grid-plane phased arra with circular boundar design of antenna which is shared b seeker and fuze is put forward. choosing the parameters and number of elements, the antenna adaptivel changes the beam pointing and flap width to meet two different working requirements of the seeker and fuze. Finall, the performance of Guidance Integrated Fuzing (GIF) antenna is simulated and validated. The results indicate that the antenna adapts to the needs of seeker and fuze, and it is a new sort to improve the coordination efficienc of fuze and warhead. 1. Introduction With the continuous developments of anti-aircraft missiles and high maneuvering targets, missile-target encountering environment is becoming more and more comple. Effective measures must be taken to improve the coordinated efficienc of the fuze and the warhead[1-3]. The Guidance Integrated Fuzing (GIF) can be interpreted that the fuze and the seeker are considered and designed comprehensivel in man was such as working principle, structure design, circuit design, signal processing, etc. Integrated design of fuze and seeker antenna can make sure that fuze makes full use of the related information to adaptivel control the detonation of warhead and make the fragment aim at the target. The seeker can not onl guide missile flight but also control the detonation of warhead adaptivel. The central content of the GIF is that the fuze and the warhead share the information and equipment with each other. This technolog is presented to improve the coordinated efficienc of the fuze and the warhead and make sure anti-interference performance and reliabilit of the detonating sstem. The most important technolog of the GIF on hardware is the integration design of the target detection device. It should not onl ensure that the fuze can obtain the information accuratel but also ensure that the seeker can search, capture and track the target. The beam inclination angle and the beam width are two important parameters during the design of antenna.. Integrated Design of Antenna The theor of the integrated design of fuze and seeker antenna based on phased-arra technolog is shown as Fig.1. The sstem is based on the active phased-arra antenna and each element is made up of the transceiver, the phase shifter and power dispatcher, etc. The power distribution and composition sstem presents transmit power and forms receiving beam. eam controller is the particular component of phased-arra seeker and fuze. It substitutes for machine scanning sstem. Under the control of the information processing machine, beam controller calculates controlling code which each phase shifter of antenna element needs and transmits it to the driver. In the diagram, the fuze and seeker share the phased-arra antenna, signal and data processing equipment. At the beginning of the approach of missile and target, antenna sstem chooses working condition of the seeker to provide information for the sstem of guidance and control for missile. At the stage of the terminal guidance, antenna sstem switches to the working condition of fuze. Make sure the fuze detect the target and control adaptivel the detonation of warhead The authors - Published b Atlantis Press 511

2 Fig.1 The function block diagram of the GIF antenna 3. Theor of Phased-arra Antenna 3.1 asal principle [4-7] Phased-arra antenna can scan simultaneousl in two directions which are pitch plane and bearing plane. The chart of rectangle phased-arra antenna on plane and 3D beam-scanning picture are shown as Fig.. On o plane, the sum of antenna arra elements is M N and the spacing between the elements can be described with d d and z z Target ( r,, ) 0.5 i,0 0,0 o φ d i,k 0,k d Fig. Rectangle phased-arra antenna on plane and 3D beam-scanning picture Supposing the position coordinate of target is (cos cos,cos sin,sin ), the pattern of the phased-arra antenna F, ) can be defined as follows: ( j[ i( d cos cos ) k ( d cos sin )] ik e F(, ) (1) i k Where is the phase difference of two adjacent elements in the X ais direction and is the phase in the Y ais direction. If ( / ) d cos cos and( / ) d cos sin, the maimum value of the pattern of the phased-arra antenna can be derived. Therefore, changing and can lead to the adjustment of beam direction and beam scanning. 3. eam width Reference to Fig., the beam width in φ direction remains unchanged even if scanning angle changes. Yet the beam width in direction will broaden if the scanning angle increases. When phased-arra antenna doesn t scan, its beam will be like a pencil and half power beam width is The radius of projected circle on a plane can be epressed as r sin( 0. 5 / ). When the direction of beam is (, ), beam onl make the operation of translation on o plane according to the geometrical theor, the beam width can get through geometrical operation as follows: sin1 sin sin( 0.5 / ) () sin sin sin( 0.5 / ) 51 φ o

3 ased on the above operation, the beam width 0. 5 can be obtained as follows: arcsin[sin sin( 0.5 / )] arcsin[sin sin( 0. 5 / )] (3) 3.3 Spacing between arra elements Reference to the rectangular grids, it is necessar to choose wide spacing as far as possible to reduce the number of elements needed if there is not grating lobe. If working frequenc and maimum scanning angle m are confirmed, the maimum spacing of antenna elements d, d can be obtained as follows: d /(1 sin ) (4), d m 3.4 Talor linear source integrated model Reference to the linear source, ideal space factor [8-9] can be replaced with Talor space factor. n 1 ( n 1)! m F( m, A, n) ( n 1 m)!( n 1 m)! 0 n1 1 A ( n 1/ ) m n m n Where σ is broadening factor and it can be defined as follows: 1 n /( A n ) (6) n is the divided point between the area of uniform side lobes and the area of various side lobes. It should be ensured that the increase of n will lead to the decrease of σ. So the requirement of n is provided as follows: n A 1. Therefore incentive amplitude of Talor arra elements can be epressed as: n 1 n ) 1 F( m, A, n) cos( mp n m1 f ( p ) (7) dn / L n 0,1,, N N is an odd number with p n (8) d (n 1) / L n 0,1,, N 1 N is an even number The main lobe width of Talor arra pattern can be derived as: arcsin arccosh R arccosh( R / ) (9) L Supposing aperture is based on the Talor distribution, the maimum distance between elements without grating lobes is given b: d (10) 1 sin ma Where is reduced factor of arra spacing and it can be defined as follows: ( N 1 ) / N and is zero adjustment parameter of the pattern and it can be obt ained b solving the following equation. ( R13.614) 0 sinh( ) 10 (11) (5) 4. Installed Design of Antenna The GIF antenna is required not onl to achieve the aim of guidance and control, but also to finish detonating fuze. From the perspective of structure and installed was of integrated antenna, rectangular-grid-plane antenna which has circular boundar can be adopted and the wa of installing is shown as Fig.3. The design method of antenna was developed b separating the caliber. First, two main planes ( 0 and 90 )can be designed according to the Talor linear source integrated model and corresponding currents are obtained. If the two kinds of currents are multiplied together, the current distribution of each element will be obtained and each technique inde can achieve or even precede the prescribed standard. 513

4 Technical parameter of the GIF antenna is shown as follows: working frequenc f=35ghz; the range of beam width is from 3 to 8 ; the range of scanning angle in direction is ±65 and in 0. 5 φ direction is 360 ; antenna gain is greater than 8d; Side lobe voltage is less than -30d. Target z (-i,-k) φ (0,k) (i,0) Fig.3 sketch map of antenna setting According to the above technical requirements and installation conditions, square arra antenna is designed firstl and the distribution of antenna caliber field is designed based on Talor arra. Linear source is designed according to the following steps. (1) To choose relative parameters of Talor arra. When n 5, R 50, side lobe voltage can be epressed as follows: E p 10lg R d 30d (1) A arccosh R / (13) Thereupon n / A ( n 0.5) (14) () Considering the conditions of the beam width, gain and grating lobe, we can quantif caliber size and the distance between elements. When L=18cm and N=19, d/λ can be obtained, that is The beam width 0. 5 of the antenna without scanning can get through the operation as follows: arcsin R 171 L arccosh R arccosh( / ) 3. (15) When the antenna is scanning, 0.5 ma can be obtained according to the Eq.(3). 0.5 arcsin[sin 65 sin( 0.5 / )] arcsin[sin 65 sin( 0. 5 / )] (16) Directivit factor of phased-arra antenna is connected with scanning angle and minimum can be obtained as follows: Dmin Dmin D1 cos ma (17) Where D 1 is directivit factor of linear source. Considering that the aperture of the antenna is small, the efficienc can not be ver high. So supposing the efficienc 0. 6, the gain can be obtained get through the following operation. G min 10lg( Dmin ) d 8d (18) According to Eq.(11), we can easil obtain ( N 1 ) / N (19) Then we have d sin ma (0) From Eq.(0), we can see that the antenna will not cause grating lobes. (3) To calculate incentive amplitude of Talor arra elements. Considering the smmetr of Talor distribution, we can choose the L/ position as the position 514

5 of reference point and onl need to calculate half incentive amplitude. Performing integration b part for Eq.(8), and taking the σ and A calculated into consideration, we have F ( 1, A,5) F (, A,5) F ( 3, A,5) F ( 4, A,5) Substituting the above calculation into Eq.(10), the tabulation of incentive amplitude of Talor arra elements is shown as Tab.1. Then the specific design of square linear source arra is completed. The diameter of plane is 18cm and the number of elements is The distribution of antenna aperture field is shown as Fig.4. If the GIF antenna sstem chooses working mode of seeker, all elements will be operated. When the sstem switches to the working condition of fuze, the number of elements will decrease and there will be onl 1 elements to run to ensure the fuze deal with the information quickl. Table 1 Incentive amplitude of Talor arra elements elements f (p 0 ) f (p 1 ) f (p ) f (p 3 ) f (p 4 ) f (p 5 ) f (p 6 ) f (p 7 ) amplitude elements f (p 8 ) f (p 9 ) f (p 10 ) f (p 11 ) f (p 1 ) f (p 13 ) f (p 14 ) f (p 15 ) amplitude elements f (p 16 ) f (p 17 ) f (p 18 ) f (p 19 ) f (p 0 ) f (p 1 ) f(p ) amplitude Incentive amplitude 口径场电流幅度 Y-units 方向阵元序号 Z-units z 方向阵元序号 Fig.4 Installation diagram of antenna element and distribution of antenna aperture field 5. Eperiments and Simulation To describe scanning situation of the GIF antenna sstem preferabl, we can suppose u sin cos, v sin sin that is a tan( u / v), a sin u v. The figure of converting the spherical coordinates to U, V space is shown as Fig.5. Therefore φ can be replaced with u, v and scanning capabilit of beam will be epressed intuitivel. Fig.6 is antenna gain direction of 3D graphs and line graphs at seeker state while beam-scanning angle 0, 65 0 and based on size N r =45, d d that is the working mode of seeker. Fig7 is antenna gain direction of 3D graphs and line graphs at seeker state while beam-scanning angle 0, 65 0 and based on size N r =1, d d that is the working mode of fuze. In these figures, the beam shapes based on several different angles are presented. Line graphs describe the value of antenna gain in different conditions. The GIF antenna will form the beams with different shapes and direction based on different azimuth angles and elevation angles. Moreover, it can scan in two working modes that are seeker and fuze. 515

6 1 V U φ Fig.5 Converting the spherical coordinates to U,V space Fig.6 antenna gain directions of 3D graphs and line graphs at seeker state while beam-scanning angle 0, 65, 0 and 45,

7 Fig.7 antenna gain directions of 3D graphs and line graphs at fuze state while beam-scanning angle 0 65, 0 and 45, Summar ased on the features of Phased-arra antenna, we design the GIF antenna sstem that can not onl adapt to active-radar seeker but also meet the technical requirements of fuze. At the beginning of the approach of missile and target, antenna sstem chooses working condition of the seeker to provide information for the sstem of guidance and control for missile. At the stage of the terminal guidance, antenna sstem switches to the working condition of fuze. Make sure the fuze detect the target and control adaptivel the detonation of warhead. The information of the target can be made comprehensive use of and volume and weight of will decrease. The coordinated efficienc of fuze and warhead can be improved ver well. However this technolog will cause some problems such as it is ver difficult to choose appropriate time to switch different working modes. Moreover phased-arra antenna is ver epensive and miniaturization is ver difficult, which is needed to be solved step b step in the future. Reference: [1] ZHU Xue-ping, MENG Jiang-hao, XU Tao, YANG Jun. Integration Guidance Technolog of Phased Arra Radar Seeker ased on Maneuvering Target Tracking [J]. College of Astronautics Northwestern Poltechnical Universit, 013.5: [] FAN Hui-tao, YAN Jun. Development and outlook of active electronicall scanned arra guidance technolog [J]. Acta Aeronautica Et Astronautica Sinica, 015.9: [3] Fan Hui-tao. Design principle of air to air missile [M]. eijing: Aviation Industr Press, 013(in Chinese) [4] Mark Engel, Eith Lewis, HowieWendt. GIF Guidance Integrated Fuze. NDIA 47th Fuze Conference [5] LIU Hua-ting, GUO Yan-chang, LIU Zhen-guo. Reduction of spur in DDS based on appropriate random phasing in phased arras [J]. Journal of Microwaves, (4):7-74. [6] Qiu Yuan-Yuan, Xu Yang. Optimization of side-lobes generated from a phased arra using Gaussian superposition technique [J]. Journal of Nanjing Universit(Natural Sciences) : [7] FU Hao, LI Xiao-hao, LI hui-lian. Research on the technologies of conformal phased arra antenna [J]. Popular Science & Technolog, 014.8:3-6. [8] WANG Xuan, DENG Jia-hao, LI Hui, LU Man-jun. Terminal Target Contour Reconstruction Algorithm ased on RF Imaging for GIF [J]. Acta Armamentarii, 015.9: [9] DENG Fang-i, ZOU Yi. Simulation of stable tracking control for gimbal of phase arra seeker [J]. Sstems Engineering and Electronics, 013,:

8 [10] Alekse K, Serge K, Serge S. A new technique for sandwich antenna radomes analsis[c]//014 Loughborough Antennas and Propagation Conference. 014: