Research and Development of a Differential Microwave Attenuator Based on BiCMOS SiGe Technology with Continuous Attenuation Control

This article presents the development of a differential microwave attenuator based on BiCMOS SiGe technology. Field-effect transistors were used as variable impedances. Attenuation then achieved by using the compensation technique. This allows continuous adjustment of attenuation with minimal insertion losses. The applied method allowed us to obtain a high level of linearity with single-ended P1dB compression values of at least eight dBm. The frequency range of the effective attenuation is 1 - 12 GHz, with a maximum attenuation factor of at least 32 dB. The circuit and layout are presented, as well as an assessment of the influence of parasitic components on the characteristics of the microwave attenuator.