Development Of Ka-band Miniaturized Radar Front-end

Radar has been widely used in both military and civilian applications since its born,such as anti-terrorism early warning,search alert,navigation,traffic speed measurement and so on.With the development of technology,the performance and volume of radar have become the focus of various application fields,which will inevitably promote the development of high performance and miniaturization of radar.Millimeter wave has the characteristics of short wavelength,strong penetrating ability,and narrow beam;these characteristics make the millimeter wave radar easy to achieve miniaturization,more reliable operation,and higher distinguishability.The radar front-end plays an important role in radar system,so it is meaningful to develop a high-performance,miniaturized radar front-end.Based on the radar front-end theory,this paper designs a miniaturized radar front-end that works in the Ka band combined with the requirements of miniaturization and high performance.The front-end can be divided into three parts: frequency synthesizer,transmitter and receiver.The frequency synthesizer is used to generate three channels of synchronization signals and one channel of local oscillator signal shared by the transmitter and receiver;the transmitter up-converts the intermediate frequency signal with a center frequency of 750 MHz to the Ka band,and after amplification,it can be directly sent to the antenna for radiation;The echo signal reflected by the target is received by the antenna,and then the center frequency is changed back to 750 MHz after filtering,frequency conversion,and amplification by the receiver,and then sent to the signal processing unit.The main contents of this paper are as follows:Firstly,it introduces the use and classification of radar,clarifies the important role of radar front end in radar system,analyzes the advantages of millimeter wave and millimeter wave radar,then investigates the development status of miniaturized front-end circuits at home and abroad.Secondly,it introduces the theoretical basis needed to design the radar front end,including the principle and main parameters of transmitter,receiver,frequency synthesizer;basic principles and parameters of mixer,filter,amplifier,pulse modulation circuit,microstrip-waveguide transition structure.Then based on the theory and design requirements,the overall plan of the radar front end is put forward;we complete the selection of all components,draw the schematic and layout,then design the cavity.After finishing the processing and assembling work,we debug and test the actual design,record the test results of all indicators.Finally,it summarizes the main work of the full text,the measured indicators,some problems and solutions encountered in the work;then proposes the direction for improvement in the next step.