Stdio-Wcalc: coupled_microstrip

Stdio-Wcalc: coupled_microstrip_syn

coupled_microstrip_syn - Coupled microstrip transmission line synthesis

SYNOPSIS

coupled_microstrip_syn z0 k z0e z0o w s h l tmet rho rough er tand f flag

PARAMETERS

INPUT PARAMETERS

z0 : desired characteristic impedance (Ohms)
k : desired coupling coefficient
z0e : desired even mode characteristic impedance (Ohms)
z0o : desired odd mode characteristic impedance (Ohms)
w : width of coupled microstrip line (meters)
s : spacing between coupled microstrip lines (meters)
h : substrate thickness (meters)
l : length of coupled_microstrip line (meters)
tmet : metal thickness (meters)
rho : resistivity of wire (relative to copper)
rough : conductor surface roughness (meters-rms)
er : substrate relative permitivitty
tand : substrate loss tangent
f : synthesis frequency (Hz)
flag : indicates which parameters should be optimized
- flag=1 : synthesize based on characteristic impedance and coupling coefficient
- flag=0 : synthesize based on even and odd mode characteristic impedances

OUTPUT VALUES

w_out : calculated metal width
s_out : calculated gap
l_out : calculated metal length

DESCRIPTION

Function to synthesize the physical dimenstions of a coupled microstrip transmission line to achieve a desired characteristic impedance and electrical length. The desired characteristic impedance and some of the physical dimensions of the coupled_microstrip line are given as inputs and the remaining dimensions are calculated. The line may be specified either in terms of an even mode and odd mode characteristic impedance or a characteristic impedance and coupling coefficient. The model accounts for dispersion (frequency dependent propagation velocity).


              |<--W-->|<-S->|<--W-->|
               _______       -------
              | metal |     | metal | <- rho,rough
    ----------------------------------------------
   (  dielectric                         /|\     (
    )   er,tand                       H   |       )
   (                                     \|/     (
    ----------------------------------------------
    XXXXXXXXXXXXXXXXXX ground XXXXXXXXXXXXXXXXXXXX

EXAMPLE

* ze = 55.27, zo = 45.23, ke = 2.261, ko = 2.009
coupled_microstrip_syn 50.000 0.1000 90 2.763e-3 1.213e-3 1e-3 1.0 0.0 1.72e-8 0.0 2.55 0.0 6e9 0
coupled_microstrip_syn 55.277 45.227 90 2.763e-3 1.213e-3 1e-3 1.0 0.0 1.72e-8 0.0 2.55 0.0 6e9 1
*