| The Traditional active beamforming schemes are usually composed of tile or brick TR modules,which is a complicated process.With the development of IC device technology,monolithic microwave IC can be widely used.Therefore,the design of antenna arrays using integrated IC and beamforming antenna systems are of great value in applications.In this paper,the development and present situation of integrated front-end RF chip at home and abroad are analyzed.At the same time,the phased array antenna theory and typical circuit of transceiver are introduced.Beam forming circuits can be divided into analog and digital forms.The beamforming circuit is actually the antenna front part of the RF circuit.Then,this paper designs antenna front-end applications based on two highly integrated BF chips of different frequency bands,and also designs a RF system of a high frequency transceiver.In this paper,two typical planar beamforming systems and a 77 GHz transceiver widely used in vehicle-mounted radar are designed based on beamforming circuit and transceiver RF circuit respectively.(1)Design of Ku-band beamforming antenna front-end system.A phased array system for frontier inspection is designed by using ADI’s integrated beamforming chip ADAR1000 and TR component chip ADTR1107.The Ku-band microstrip antenna is designed according to Taylor synthesis method,which includes two kinds of antenna designs: line-to-surface array and bottom-fed surface array.According to the different feeding mode of antenna array,the system has two layout modes.Secondly,the hardware circuit is designed,which is divided into three parts: radio frequency part,power supply part and control part,at the same time completed the hardware circuit schematic design and PCB design.The active array antenna can scan ±45° in azimuth,the normal gain is greater than 20 d Bi,and the side lobe is less than-25 d Bi,which meets the design requirements of the system.(2)Design of Ka-band beamforming antenna front-end system.The RF front-end circuit is designed using ADI dual-polarization beamforming chip ADMV4828,which can be used in satellite communication applications.Firstly,the circularly polarized antenna element is realized in the form of magnetoelectric dipole,and the circularly polarized phased array is formed in the form of rotating feed,which can realize ±50° beam scanning.After that,digital circuit and analog circuit are designed according to system requirements.In order to ensure the RF analog signal receiving,it is necessary to provide power supply and store information circuit around.The design of the system based on the schematic diagram of beamforming system and PCB is completed.(3)Design of 77 GHz transceiver system.The system can be used in transceiver of 77 GHz radar simulator.According to the superhet structure,the system firstly selects the front-end chip that conforms to the link,and then designs the passive components of RF front-end,including local oscillator filter,RF filter and microstrip transform waveguide structure.According to the positive and negative voltage required by the system,the power supply circuit is designed and the timing is tested.Design a complete RF transceiver link,processing the physical object,the test shows that the working band can realize the transceiver signal. |
PDF Full Text Request