C_MIM

	C_MIM Coplanar Metal-Insulator-Metal Capacitor Parameters Notes Equivalent Circuit
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Coplanar Metal-Insulator-Metal (MIM) Capacitor

The C_MIM module represents a series metal-insulator-metal capacitor (MIM-Capacitor) in coplanar line technique. The width of capacitor and its distance to the ground are given in a line type addressed by C_LTYPC. The total length of the capacitor is given by L. The dimensions of connected lines at ports are defined using data items addressed by C_ LTYP1 and C_LTYP2.

Parameters

Parameter	Description	Range of Usage
L	Total length of the capacitor
C_LTYPC	ID of coplanar transmission line applied at capacitive section
C_LTYP1	ID of coplanar transmission line applied at ports 1
C_LTYP2	ID of coplanar transmission line applied at ports 2
DIE_IDX	Index to dielectric layer definition for capacitors in currently selected foundry
C_SUB	ID of coplanar substrate definition
C_GRID	ID of simulation control data
TEMP	ID of element temperature definition used for noise computation

Notes

Presently, the C_MIM module is not able to calculate the steps which are made if different line types are used for C_LTYP1, C_LTYP1 and C_LTYPC. Therefore, if a step configuration is used for layout reasons, the effect of such discontinuities are not taken into account during the simulation.
L is the total length of the capaciotr. Note that the effective length of the capacitive section is given by L- 2.cap_l. Therefor L has to be greater than 2.cap_l.
The connected lines addressed by C_LTYP1 and C_LTYP2 must have different CEN_MET.
The index DIE_IDX is used for the selection of the desired dielectric layer in selected foundry. In case of DEFAULT foundry, two different dielectric layers are available (DIE_IDX =0 is not allowed). If DIE_IDX=1, the parameter die_h1, die_er1, die_td1, cap_l1 and cap_os1 are used.
The oversize of lower metal plate is defined by the keyword cap_os in selected foundry. Note, that the slot S in C_LTYPC must be greater than cap_os (S_min = cap_os +DL).
If L1 in selected C_GRID is not set to –1 or –2 (auto sizing), the minimum values for L1 is:

L1_min= max( W1+2S1+2GW1, W2+2S2+2GW2, WC+2SC+2GWC)

Equivalent Circuit

For the modeling of C_MIM element, the capacitive region is calculated as two coupled coplanar lines (see Analysis of Multiple Coupled Coplanar Lines). The matrices of distributed parameters (capacitance per unit length, inductance per unit length, etc.) are determined using quasi-static FD-calculations.