A 6-Bit MMIC Digital Attenuator With Low Insersion Loss And Large Attenuation

With the continuous development of microwave communication, communication systems require high-performance and miniaturization of integrated circuits to meet the increasingly complex requirements of the user constantly. Ga As monolithic microwave integrated circuit is in line with this requirement. Such circuit has high levels of reliability, light weight, high component density, design flexibility, wide frequency band and small power consumption. Microwave digital attenuator can be adjust the amplitude of the signal through specific control signal. The main indicators include attenuation accuracy, dynamic range, insertion loss and VSWR, etc., its performance is often directly affect the entire circuit system performance.In response to these problems, this paper in order to design an attenuator with low insertion loss, large amount of attenuation, high attenuation accuracy and good port VSWR as the basic content, in addition to achieve a positive TTL level control, integrated drive circuit, and ultimately the digital analog hybrid design. The main contents are as follows.Firstly, this article describes the development of the background, significance of the topic and overview of research progress of MMIC. It makes a detailed description and analysis to basic principles and structure of the classification for digital attenuator. It gives a monolithic model of active devices and passive components of the analysis and presentation of the p HEMT model extraction method.Then, based on these theories and models, we designed a low insertion loss digital attenuator with large amount of attenuation. To be more convenient, but also designed a drive to convert it into positive control attenuator. The final simulation curve and circuit layout have been showed.Finally, the simulation is tested and analyzed with vector network. MMIC process is carried out in the China Electronics Technology Group 13 th Research Institute of E/D process. Combined the library of process line, MMIC attenuator excellent finally produced. Sample test results meet design requirements.