Monolithic Microwave Integrated Circuit

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Geometric structure of the chip of an MMIC
Housing of the MMIC MSA-0686 and a circuit diagram of the electrical connection of this component suggested by the manufacturer. The supply takes place through a direct voltage component at the output of the MMIC.

An MMIC (from Monolithic Microwave Integrated Circuit ) is a special class of integrated components in high-frequency technology . Here, all active and passive components on a semiconductor - substrate (. Typ thickness 100 microns) realized. The miniaturization allows circuits to in the range of millimeter waves .

With hybrid MIC technology , only some of the components can be implemented on the substrate (mostly ceramic substrate). The rest has to be equipped and has correspondingly poorer high-frequency properties due to the connecting cables.

Components

Resistors are implemented using thin-film technology or doped semiconductor material with ohmic contact . Capacitors consist of superimposed metal surfaces with silicon nitride as a dielectric . Inductors and transformers are created from spiral conductor tracks.

The conductor track is routed as a stripline and enables the use of line transformation and arrangements of coupled lines according to line theory . The typical width of a 50 Ω line is 70 µm, the thickness of a human hair .

In addition, via holes (VIA) is possible and so-called air bridges for conductor crossings.

The main active components include Schottky diodes , IMPATT diodes , capacitance diodes , metal-semiconductor field-effect transistors , high-electron-mobility transistors and heterojunction bipolar transistors .

Advantages and disadvantages

  • Cheap production in large numbers
  • Small size
  • Reproducible, consistent results
  • Big bandwidth
  • Long development cycles

literature

  • Denis J. Connolly, Kul B. Bhasin, Robert R. Romanofsky: Monolithic Microwave Integrated Circuit (MMIC) Technology for Space Communications Applications. In: NASA Technical Memorandum . 100 187 IAF-87-491 ( PDF ).

Web links