The Design And Research Of Electromechanical Combined Motion Antenna

Modern communication technology develops rapidly,more and more data transfer through the satellite.Satellite communication has a series of advantages,such as large transmission capacity,wide coverage,flexible communication mode,fast network,no influence from geographical environment and natural factors,it has gradually developed into an important way of long-distance communication."Satcom on the move" communication system is that the carrier in motion by using of satellite as a relay,to achieve real-time,large-capacity,uninterrupted transmission of multimedia information,has become one of the most promising directions in modern communications industry.In this paper,according to requirements of the specific S-band "Satcom on the move"project,The system indicators decomposition of the antenna,radio,turntable indicators,Antenna using mechanical scanning and one-dimensional active phased array combination.The azimuth direction is tracked by mechanical continuous rotation mode,and the pitch direction is tracked by phase control.I designed two antennas of "Satcom on the move",the specific work is as follows:Using air-coupled microstrip antenna laminated form,I designed a dual-band left-handed circularly polarized antenna.The antenna adopts double feed-point feeding to realize left-handed circular polarization,two-layer circular patch achieves dual-band matching and the ceramic bridge builds miniaturized power divider to realize the feeding network.Through the unit antenna simulation and optimization,it achieves the index requirements.Then,a 3 ×4 microstrip antenna array was designed,the antenna consists of 3 rows,4 antenna elements in each row form a uniform linear array and the 3 ports are combined with T/R components,After simulation,processing,assembly,testing,microstrip antenna array test results and simulation results are basically the same.Due to the planar microstrip structure of the antenna,the gain of the antenna decreases rapidly in scanning.In order to make up for the disadvantage of low elevation gain,a left-handed circularly polarized helical antenna was designed.Spiral lines are equally spaced around the hard POM material,through the unit antenna simulation and optimization,helical antenna bandwidth covers the dual-band.Then,the 3*4 array,as with the air-coupled microstrip cascaded antenna array,each row of four helical antenna elements form a linear array,1*4 network using microstrip coplanar waveguide feed,3 combiner ports are connected to T/R module,antenna and feed network integration design,after simulation,assembly,connection T/R component testing,the results of the designed helical antenna arrays are in good agreement with the simulation results.The helical antenna itself can radiate circularly polarized waves,without the need to design additional orthogonal feed networks,the antenna weight is reduced by 80g.Due to the antenna’s three-dimensional helix,the gain at low elevation is increased.On the basis of the array design,it realizes "Satcom on the move" antenna,Not only combine of the low price of mechanical sweep,to ensure that the beam is always aimed at the satellite,send and receive have more efficient advantages,but also combines the reliability of phased array electro-sweep,the advantages of fast tracking satellite.Significantly improve the vehicle moving through the equipment in the sharp bumps track speed.Antenna panel tilt installation,scanning at low elevation angle also have a higher gain and efficiency,the design of mechanical and electrical integration "Satcom on the move" has a strong engineering practicality.