page_title: Port (circuit theory)
section_title: Waveguide
hierarchical_section_title: Port (circuit theory) / Waveguide
caption_attribution_description: Deutsch: Hohlleiter-Richtkoppler, Abzweig mit reflexionsfreiem Abschluss für die ungenutzte Richtung, Hohlleiterbreite 23&#160;mm entsprechend einer Arbeitsfrequenz von ca. 9&#160;GHz. Die Kopplung zwischen den Hohlleitern wird durch zwei Löcher erreicht. English: Moreno cross-guide directional coupler. The limb with no port-flange incorporates a matched load. The waveguide is WG16 (WR90) indicating an operating frequency of about 9 GHz. The coupling between the guides is by means of two 6 mm diameter holes.
context_page_description: In electrical circuit theory, a port is a pair of terminals connecting an electrical network or circuit to an external circuit, as a point of entry or exit for electrical energy. A port consists of two nodes connected to an outside circuit which meets the port condition - the currents flowing into the two nodes must be equal and opposite.
  The use of ports helps to reduce the complexity of circuit analysis. Many common electronic devices and circuit blocks, such as transistors, transformers, electronic filters, and amplifiers, are analyzed in terms of ports. In multiport network analysis, the circuit is regarded as a "black box" connected to the outside world through its ports. The ports are points where input signals are applied or output signals taken. Its behavior is completely specified by a matrix of parameters relating the voltage and current at its ports, so the internal makeup or design of the circuit need not be considered, or even known, in determining the circuit's response to applied signals.
context_section_description: The idea of ports can be (and is) extended to waveguide devices, but a port can no longer be defined in terms of circuit poles because in waveguides the electromagnetic waves are not guided by electrical conductors.  They are, instead guided by the walls of the waveguide.  Thus, the concept of a circuit conductor pole does not exist in this format.  Ports in waveguides consist of an aperture or break in the waveguide through which the electromagnetic waves can pass.  The bounded plane through which the wave passes is the definition of the port.
  Waveguides have an additional complication in port analysis in that it is possible (and sometimes desirable) for more than one waveguide mode to exist at the same time.  In such cases, for each physical port, a separate port must be added to the analysis model for each of the modes present at that physical port.
caption: A Moreno coupler, a type of waveguide directional coupler.  Directional couplers have four ports.  This one has one port permanently terminated internally with a matched load, so only three ports are visible.  The ports are the openings in the centres of the waveguide flanges
exif: {}