home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Explore the World of Soft…e: Engineering & Science
/
Explore_the_World_of_Software_Engineering_and_Science_HRS_Software_1998.iso
/
programs
/
electrnc
/
mcgarret.exe
/
SHK-15.DOC
< prev
next >
Wrap
Text File
|
1989-10-16
|
3KB
|
56 lines
COMPUTER PROGRAM FOR BAND-PASS FILTERS USING CAPACITOR-COUPLED
RESONATORS
Written by Stanley H. Klug, ca. 1963. Edited by D. McGarrett,
1983. (Based on Stan Klug's notes.)
The class of filters which this program designs is analogous to
probe-coupled reentrant cavity resonators. The user should be
aware that high-frequency cut-off characteristics are not as good
as predicted, due to finite inductance in the shunt capacitors.
The program computes Chebychev or Butterworth filters with up to
N=9 shunt L/C resonators surrounded by series coupling capaci-
tors. The program will choose the average value of L between
theoretical limits, or, if L is given and is outside these li-
mits, the program will use the average value of inductance.
Input impedance is R1, resistive. Output load is a resistance
R2>=R1. R2 can be infinite. If infinity is greater than R2
which is greater than R1, then R2 may exceed theoretical limits,
which the program will indicate.
If the number of poles, N, is given as 0, the program will select
up to nine poles to give specified attenuation at a specified
stop-band frequency.
In order to use the program, enter the following data:
Line 10: Type "10 DATA A1,F1,F2" A1 specifies units: 1 for
megacycles, microhenries, and picofarads; 2 for kilocycles,
millihenries, and microfarads; 3 for cycles per second, henries,
and microfarads. Stick with the units you chose when entering
data. F1 and F2 are the lower and upper cutoff frequencies.
These are the -3dB points for a Butterworth filter, and can be
either the -3dB or the valley frequencies for a Chebychev.
Line 20: Type "20 DATA R1,R2,D" R1 is the source impedance,
which must be equal to or less than R2. R2 is the output (load)
impedance, and can be 1/0, or infinity, in which case, enter 0
for R2. D is any value up to 3dB ripple for a Chebychev
filter,and h≤ 0 for a Butterworth.
Line 30: Type "30 DATA A2,N,L" A2 equals 3 for a Butterworth
filter, or for a Chebychev, if F1 and F2 are the -3dB
frequencies. A2 equals 0 for Chebychev if F1 and F2 are valley
frequencies. N is the number of poles, which can be 2 to 9, or
enter 0 and the program will select the number of poles, based
upon the desired bandwidth and stop-band attenuation. Enter a
selected value for L, or enter 0 and the program will choose the
value.
Line 40: Type "40 DATA F9,D9" (If N was not 0, do not enter
D9. The program will compute attenuation at F9, a frequency
which may not fall between F1 and F2.) If N was set equal to 0,
enter D9 as attenuation desired at F9 (in dB) and the program
will select N up to 9 poles.