| Popis: |
The high-frequency behavior of electronic devices is of major interest in the field of research and development. Beside the typical RF device parameters, like the cutoff frequencies fT and fmax, the high-frequency noise behavior should be considered for circuit design, especially if noise has a significant influence on the system performance, for instance, the sensitivity of receivers. Thus, there is a demand for simple, but exact RF noise models that must consider the physically relevant noise phenomena with a significant contribution to the total noise behavior of the device. After an introduction to various physical noise sources, a general description of noisy two-ports will be presented. Then, a short presentation of a special measurement setup for RF noise in the range of 2–18 GHz with dependence on temperature (15–400 K) is given. In Section 4 RF noise phenomena in certain devices are examined and high-frequency noise models for heterostructure field-effect transistors (HFETs) and heterojunction bipolar transistors (HBTs) based on the material system InP are presented. For both devices the capabilities of the model presented will be proved by comparing measured and modeled RF noise parameters. In Section 5 modifications of the HFET noise model and applications of this RF noise model are presented. Keywords: noise; HFET; HBT; InP; equivalent circuit |
