Circuit Layout

Circuit Design and Device Modeling

GaN-HEMT MMICs

Circuits for frequencies up to X-band are realized using the FBH coplanar GaN-HEMT MMIC process. The focus is on power amplifiers (PAs), both the conventional topologies and novel circuits such as digital power switches as required for class-D and class-S architectures.

Beyond the modeling of the active device, the description of the passive elements is a key issue. Therefore, a library for coplanar elements has been developed, which covers the common discontinuities (T-junction, air bridges, ...). The models are derived by means of electromagnetic simulation and verified by measurements.

InP-DHBT MMICs for mm-wave and sub-THz frequencies

Circuits for frequencies from W-band up to 250 GHz are developed based on the InP-DHBT transferred-substrate process at FBH. Two versions of this process are available and employed for circuit realization, one on an AlN substrate, the other as an InP-on-BiCMOS variant, which offers integration of InP-HBT circuits with BiCMOS on the same chip. Activities target mainly power amplifiers, multipliers, and oscillators.

Transistor modeling

The accurate description of the active element is a prerequisite for successful circuit design. FBH research on transistor models covers all types needed for the design of integrated circuits and discretes outlined above:

  • A GaN-HEMT large-signal model for MMICs up to X-band as well as for discrete power transistors in the 1…3 GHz range. The latter comprises a full electro-thermal large-signal description of a powerbar in package, as needed when analyzing multi-cell  high-power transistors.
  • A HBT model for the W-band InP-DHBT process. The basic formulation of this model was developed for GaAs HBTs and has been in routine use also by external partners. For details, see HBT modeling.

Contact

Prof. Dr.-Ing. Wolfgang Heinrich
 Phone +49.30.6392-2620
 Fax +49.30.6392-2642
 Email wolfgang.heinrich(at)fbh-berlin.de