|  | Octave-Wcalc: coupled_microstrip_syn 
 coupled_microstrip_syn - Coupled microstrip transmission line synthesis
 SYNOPSIS[w_out, s_out, l_out] = 
coupled_microstrip_syn(z0, k, z0e, z0o, w, s, h, l, tmet, rho, rough, er, tand, f, flag)PARAMETERSINPUT PARAMETERS
z0
: desired characteristic impedance (Ohms)k
: desired coupling coefficientz0e
: 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 permitivittytand
: substrate loss tangentf
: synthesis frequency (Hz)flag
: indicates which parameters should be optimized
    
flag=0 : synthesize based on characteristic impedance and coupling coefficientflag=1 : synthesize based on even and odd mode characteristic impedances OUTPUT VALUES
w_out
: calculated metal widths_out
: calculated gapl_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 % mils to meters conversion factor
sf=25.4e-6;
 % desired impedance 
z0=75;
 % desired coupling
k=0.3;
 % desired electrical length (degrees)
elen=90;
 % width (we'll synthesize this)
w=0;
 % spacing (we'll synthesize this)
s=0;
 % height
h=15*sf;
 % length
l=1100*sf;
 % metal thickness
tmet=1.4*sf;
 % resitivity of copper
rho=1.72e-8;
 % metal surface roughness
rough=0.05*sf;
 % relative dielectric constant
er=4.5;
 % loss tangent
tand=0.01;
 % frequency
f=2.4e9;
 % synthesize from z0 and k (instead
flag=0;
 % of z0e and z0o)
[w_out,s_out,l_out] = ...
    coupled_microstrip_syn(z0,k,elen,w,s,h,l,tmet,rho,rough,er,tand,f,flag);
disp(sprintf('w=%8.4g mils, s=%8.4g mils, l=%8.4g mils',w_out/sf,s_out/sf,l_out/sf));
SEE ALSOair_coil_calcair_coil_syn
 coax_calc
 coax_syn
 coupled_microstrip_calc
 coupled_microstrip_syn
 ic_microstrip_calc
 ic_microstrip_syn
 microstrip_calc
 microstrip_syn
 stripline_calc
 stripline_syn
 
 AUTHOR
Dan McMahill
 BUGS
None known
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