Wolfgang Heinrich

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There are highly divergent data on the body m a s s (mb) of Brachiosaurus (B.). The range of the body-mass estimations lies between 14900 and 102000 kg for this giant dinosaur [1-6] . This is mainly due to the fact that different specimens and varying techniques are used for the volume (V) estimations, such as equations from the circumferences of femur and(More)
This paper presents a detailed analysis of the stressing mechanisms for highly rugged low-noise GaN monolithic-microwave integrated-circuit amplifiers operated at extremely high input powers. As an example, a low-noise amplifier (LNA) operating in the 3-7-GHz frequency band is used. A noise figure (NF) below 2.3 dB is measured from 3.5 to 7 GHz with(More)
We report on the technology and performance of fully monolithic coplanar voltage-controlled oscillators (VCOs) with GaInP/GaAs-HBTs as the active devices. With our optimized HBT process, the parasitic base resistance R/sub B/ and extrinsic base-collector capacitance C/sub EX/ are significantly reduced. In this way, the maximum frequency of oscillation F/sub(More)
State-of-the-art monolithic oscillators and VCOs using the commercially available TEMIC SiGe1-process are presented. Results comprise a 4.75 GHz buffered VCO with up to 18 dBm output power and 1 GHz tuning bandwidth, a 17 GHz oscillator with 8 dBm output power and a 25 GHz oscillator delivering 4.2 dBm. For the 25 GHz MMIC-oscillator, a single sideband(More)
Power transistors basically consist of a number of active transistors that are mounted in parallel inside the package. High powers require large transistor sizes, which translates into significant physical dimensions. For circuit design, on the other hand, a lumped model is favorable for sake of simulation speed and numerical convergence. This paper(More)
GaN HEMT technology is increasingly used not only for power applications, but also for low-noise amplification. However, systematic assessment of the validity of common noise models like the Pucel and Pospieszalski approaches are rarely found in the literature. This paper aims at closing this gap by validating the two model approaches for different devices(More)
The influence of cosmic radiation and/or microgravity on insect development was studied during the 7 day German Spacelab Mission D1. Eggs of Carausius morosus of five stages differing in sensitivity to radiation and in capacity to regeneration were allowed to continue their development in the BIORACK 22 degrees C incubator, either at microgravity conditions(More)
Residual phase-noise measurements of GaAs heterojunction bipolar transistors (HBTs) with different low-frequency noise properties are used to investigate how accurate a compact HBT model can predict the upconversion of low-frequency noise under nonlinear operation. We find that the traditional low-frequency source implementation, as well as a(More)
We study crosstalk and crosstalk corrections in coplanar-waveguide vector-network-analyzer calibrations. We show that while crosstalk corrections can improve measurement accuracy, the effectiveness of the corrections depends on a number of factors, including the length of the access lines, transverse dimensions, the separation between the crosstalk(More)