Wideband 5-bit MMIC Digital Attenuator With High Precision

This paper mainly introduces the Wideband 5-bit MMIC digital attenuator with high precision. Firstly, the theories of basic GaAs digital attenuator MMIC’s configurations are searched. Secondly, every possible configuration is contrasted, subsequently, appropriate topology is selected for each stage. This attenuator has been realized by 0.5!m GaAs pHEMT process. Simulation results of the digital attenuator has 0.25dB resolution and 7.75dB dynamic attenuation range, Input Voltage Standing Wave Ratio(VSWRIN) was less than 1.55 and Output Voltage Standing Wave Ratio(VSWROUT) was less than 1.6 for all attenuation states, high attenuation accuracy is less than ±0.26dB; insertion loss is less than 1.3dB; The layout of the digital attenuator with a chip size is 0.93 mm"1.45 mm