Multipin Waveguide Ports. ⢠A multipin waveguide port is characterized by having more than two conductors in the port region (incl. shielding). ⢠The main ...
Multipin Waveguide Ports • A multipin waveguide port is characterized by having more than two conductors in the port region (incl. shielding). • The main application is given by homogeneous multiple coaxial or connector ports. • The multipin port can also be applied to inhomogeneous ports if the propagation constants of the modes differ only slightly. Shielding
Conductors
Coax with multiple inner conductors
Multiple microstrip lines
Multipin Waveguide Ports • Definition, e.g. two differential pairs Pick face.
Press ‘OK‘, and
double-click pin
Multipin Waveguide Ports • Definition, e.g. two differential pairs Repeat with other pins
Set number = 2
...
Press ‘Close‘ to finish.
Multipin Waveguide Ports • Labeling of Multipin ports
‘Set’= mode number 1(2,+) = port number (mode number, potential)
• A ‘Set‘ corresponds to a particular definition of a mode via the potential distribution for the conductors. • Therefore, a ‘Set‘ represents a given superposition of the port‘s eigenmodes. • Pins without a potential definition are treated as a ground conductor, and potential definitions on pins for another ‘Set‘ are set to zero.
Multipin Waveguide Ports • Homogeneous multipin modes – The occurring TEM modes are degenerated (having the same propagation constant). – The TEM modes are orthogonal to each other, so that they can be superimposed to new (desired) mode patterns. – The definition of multipin modes allows you to define exactly the mode pattern that you want to excite.
Mode 1
Mode 2
Example: Differential / Common Mode Port number (mode number, potential)
“Set”=mode number Resulting Modes
Mode 2
Mode 1
“odd mode” / differential mode
“even mode” / common mode
Ethernet standards nomenclature S2(1)1(1) = SDD21 (Differential transmission from port 1 to port 2) S1(2)1(1) = SCD11 (Reflected differential to common mode at port 1)
