What types of ports are available?

Geometry Elements - Ports

All ports in Sonnet are two-terminal devices. What distinguishes the port types is where the terminals are connected. There are five types of ports available in Sonnet.

The most common type of port used is the standard box-wall port in which the first terminal is attached to a metal polygon and the second terminal is attached to the box wall (ground). This type of port can be de-embedded by em. This type of port is the most accurate and should be used whenever possible

The second type of port is the co-calibrated internal port. The co-calibrated port is used in the interior of a circuit. These ports can be used by a circuit simulation tool to connect some type of element into your geometry at a later time outside the Sonnet environment. Co-calibrated internal ports are identified as part of a calibration group with a common ground node connection. When em performs the electromagnetic analysis, the co-calibrated ports within a group are simultaneously de-embedded. For more information on co-calibrated ports and calibration groups, see Co-calibrated Ports Calibration Groups.

The third type of port is the via port. A via port has one terminal connected to a polygon on a given circuit level and the other terminal connected to a second polygon on a circuit level above or below the first polygon. Em cannot de-embed a via port. A via port is most commonly used when you wish to attach a port between two adjacent levels in your circuit or when you want a port to go up to the box cover rather than down to ground.

Occasionally, however, it is useful to attach the two terminals of a port between two adjacent polygons. This is the ungrounded-internal port. This type of port can be de-embedded by em; however, you may not set a reference plane or calibration length for the port. When analyzing multi-port circuits to find S-, Y- or Z-parameters, all of the ports in the circuit should be grounded. An ungrounded port can have a different ground reference from other ports in the circuit, which, in turn, can corrupt the results.

The fifth type of port is the auto-grounded port. The auto-grounded port is used in the interior of a circuit and has one terminal attached to the edge of a metal polygon and the other terminal attached to the ground plane through all intervening dielectric layers. Em can de-embed an auto-grounded port. This port is not as accurate as a standard box-wall port or a co-calibrated port, so you should only use it when necessary.

See the "Ports'' chapter in the Sonnet User's Guide for a detailed discussion of ports and their use. The manuals are available on your system in PDF format by clicking on the Manuals button on the Sonnet task bar or by selecting Help => Manuals from the main menu of any Sonnet application.