# Chapter 9 THEORY AND DESIGN OF FERRIMAGNETIC COMPONENTS¶

## Example:9.2 page.no:525¶

In [1]:
# program to design an e plane resonance isolatorin x band waveguide .

er =13; revatt =30;
deltaH=200;x=1700; # x=4⇤pi⇤Ms.
f=10*10**9;alpha_=12.4; # from graph 10.13.
L=revatt/alpha_;
alpha_1=27/L;
print "for total reverse attenuation of 20 db,the length of the slab in cm must be = ",L
print "for total reverse attenuation to be at least 27 db, alpha in db/cm be > ",alpha_1

for total reverse attenuation of 20 db,the length of the slab in cm must be =  2.41935483871
for total reverse attenuation to be at least 27 db, alpha in db/cm be >  11.16


## Example:9.3 page.no:528¶

In [2]:
# program to design a resonance isolator using the H-plane ferrite slab geometry in x-band.
from mpmath import atan
from math import pi,sqrt

f=10*10**9;delta_sbys=0.01;forpims=1700;deltaH=200;
revatt=30;ko=(2*pi*f)/(3*10**8);
Ho=f/(2.8*10**9);
# for x-band waveguide , a=2.286 cm.
a=2.286;
kc=(pi*100)/a;
betao=sqrt(ko**2-kc**2);
x=(1/pi)*atan(kc/betao); # x=c/a .
L=revatt/2;
print "the slab length required for 30db total reverse attenuation in cm = ",L
print "cut-off wave number in m-1 = %.3f"%kc
print "propagation constant = %.3f"%betao

the slab length required for 30db total reverse attenuation in cm =  15
cut-off wave number in m-1 = 137.428
propagation constant = 158.046


## Example:9.4 page.no:532¶

In [3]:
# program to design a two slab remanent phase shifter .
from math import pi

forpims=1786;er=13;f=10*10**9;
uo=4*pi*10**-7;ko=(2* pi*f)/(3*10**10);
fm=2.8;s=0.1;# s and a in cm.
x=(2*pi*fm*forpims)/(2*pi*f);# x=wm/w = k/uo. 6 a=2.286; # for x-band.
t=.274; #from figure 10.19;
diffphaseshift=0.4*ko*(180/pi); # differential phase shift .
L_1=180/diffphaseshift;
L_2=90/diffphaseshift;
print "the ferrite length required for the 180 deg phase shift section in cm = ",L_1
print "the ferrite length required for the 90 deg phase shift section in cm = ",L_2

the ferrite length required for the 180 deg phase shift section in cm =  3.75
the ferrite length required for the 90 deg phase shift section in cm =  1.875