The Research Ofdigital T/R Module And Design For Digital Transmit Channel

Phased Array Radar is very important part of the modern radar system.With thedevelopment of digital technique and hardware, the function that can only beimplemented by analog circuits,now can be implemented by digital circuits.It drivesDigital Array Radar which uses digital beamforming technology in receiving andtransmitting appearance. Digital T/R Module as the core part of the Digital Array Radarwhich DDS(Direct Digital Synthesize) is the core part is a new T/R module.It uses DDStechnique to achive transmitting and receiving beamforming in IF or lower frequency byusing digital method which realizes phase control and amplitude weighting.First, this dissertation introduced the background of the Digital T/R Module bycomparing the Digital Array Radar and traditional Phase Array Radar, later introducedthe current-state of the Digital T/R Module,expatiated the main work of thisdissertation.Second, the dissertation compared the capability of the traditional T/R module andDigital T/R Module,and then introduced the basic theory of Digital T/R Module, mainlyintroduced the technique of DDS.At last presented a scheme of C bandwide bandDigital T/R Module.Third, the dissertation introduced the design of the Digital T/R Module, mainlyintroduced the transmit channel design,I ncluding:the crystal oscillation,DDS,the localoscillation,up frequency conversion,power amplifier.And simply introduced the designof the receive channel.Finally, the dissertation showed the system’s pictures and the test data,validated thecapability of the digital transmit channel,and gave the summary of the wholeprocess,found the direction for optimization.The results show that:work band5.3GHz～5.9GHz,modulation band1MHz～10MHz,phase shift range of0o～360o,the max attenuation15dB,the max peak power50W,the max work duty25%,spurious suppression≥60dBc,meets the requirements.