C_OPEN Coplanar Open End Parameters Notes Equivalent Circuit
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Coplanar Open End C_OPEN module represents an open at the end of a coplanar line. The dimensions of the line connected to the open are defined in data item addressed by C_ LTYP. L is the length of the connected coplanar line. GAP is the distance between the open end and ground planes and WG is the extension of the ground plane at the end of line.

Parameters  

Notes

• A negative value for L can be meaningful during the simulation. In such cases, the automated layout generation works incorrectly and the generated layout has to be edited manually. The minimum value for L depends on the metal layer oversize in the currently selected C_LAYER. In case of DEFAULT foundry, L should be greater than or equal to max(|cond_os|, |cond2_os|).
• For WG =0, infinite ground plane at the open end is assumed.
• TYPE indicates the form of open end. There are two types of open ends as shown in the illustration bellow.If TYPE= No_Ground_Connection is selected, the parameters WG and GAP are ignored.

  TYPE = Ground_Connection	TYPE = No_Ground_Connection

• If L1 and L2 in selected C_GRID are not set to –1 or –2 (auto sizing), the minimum values for L1 and L2 are:

  L1min=W+2S+2GW

  L2min=8DL+GAP+WG

Equivalent Circuit  

For the modeling of the C_OPEN element, an equivalent capacitance is used. The value of this capacitance is derived from quasi-static FD-calculations. The connected line at the port is modeled as a C_LIN element and is represented by its characteristic impedance ZL and phase constant b. There is no limitation due to the length of connected line L.