Fully Integrated Bandpass Filter with High Isolation Attenuator Function Using Semi-conductor Distributed Doped Areas

In this paper, a quarter wavelength coupled lines X-band bandpass filter (BPF) integrating an attenuator feature is presented. The high rejection analog attenuator uses integrated Semiconductor Distributed Doped Areas (ScDDAs) on silicon substrate as tunable resistors. The measured insertion loss of 2.8 dB and attenuation range of 42 dB allow a precise control of the transmitted power for highly integrated systems. A coupled semiconductor physics and electromagnetic structure simulation framework is also proposed in retro-simulations to improve design accuracy of distributed semiconductor devices.