CP/M/CPM_CDROM.iso/lambda/soundpot/f/network.lbr/NETWORK.DZC/NETWORK.DOC

Text File | 1993-10-26 | 5.9 KB | 109 lines

                          NETWORK.BAS  Ver 1.0

                        NETWORK ANALYSIS PROGRAM



1. INTRODUCTION:  This program may be used to design passive electrical
networks.  Passive components, such as resistors, capacitors, inductors
and transmission lines are evaluated versus frequency.  Both series and
shunt circuits are included.  Once a circuit is designed and optimized,
it can saved as a NETFILE for future use.  Three netfiles can be stored
on RAM by the program as now configured (add more files by changing the
program at line 130).  This program used with AMPGAIN will allow active
circuits, such as amplifiers or active filters, to be designed.  Both
shorted and open transmission line stubs are simulated.

2. DATA ENTRY:  Components are entered by code and value.  Codes are (+)
for series connected parts and (-) for shunt connected parts.  The code
useage is shown in the program INFO screen and listed here as follows:

        CODE    TYPE    CIRCUIT         CODE    TYPE    CIRCUIT
         1    Resistor   series          -1   Resistor   shunt
         2    Inductor   series          -2   Inductor   shunt
         3    Capacitor  series          -3   Capacator  shunt
         4    Transmis.  series          -4   Transmis.  shunt
         5    RLC ckt.   series  (in shunt)     none

3. COMMANDS:    After the circuit elements are entered, changes are easy
since only a <CR> at the F0 prompt will allow any element to be changed
by entering its number and new value.  The program then returns to the F0
prompt for evaluation.  A <CR> at the Elem prompt returns to the F0 prompt
again.  The frequency code commands are as follows:

        NO.     ACTION          NO.     ACTION
        -1      F-sweep         -2     New RG,RL
        -3     Elem List        -4     New ckt.
        -9     Save ckt.       (in files 0,1 or 2)

A (-3) at the F0 prompt will show the element list.  The element number,
code and size are shown in the first three columns.  The next two columns
do double duty as either the inductor and capacitor of an RLC circuit are
listed, or the EDC and length of a transmission line are shown, otherwise
these two columns are zero.  The last column shows the TML loading cap.
When a transmission line element (type 4) is changed at the F0 prompt,
the program asks for the (SYMB)ol#.  The symbol list follows:

        SYMBOL#         LINE PARAMETER
          1           Line Impedance (Z0)
          2           Effective Dielectric Constant (EDC)
          3             Line Length
          4             Line Load Cap

The load cap is used to simulate an open or short circuit shunt stub.  A
small cap value simulates an open stub with fringing and a large cap will
simulate a shorted stub.  The cap value should be large enough so that its
reactance is negligible over the desired operating band of frequencies.  A
(-1) entered at the Elem prompt allows a new element to be added.  A (-1)
entered at the Size prompt calls the Element Code input and the new part
code is specified.  Then, size can be entered in the normal manner.  The
frequency sweep is started by a (-1) at the F0 prompt.   The starting
frequency is entered, followed by the delta frequency (+ or -). The sweep
will continue until interupted by Control-C.  Set L=0 and use the CONT
command at the Basic prompt.  The program will return to the F0 prompt.

4. PROGRAM OUTPUT:   Three NETFILES are included as examples of program
operation.  NETFILE.0 is a 3 dB PI resistance pad with three resistors,
a shunt, a series and another shunt.  This arrangement allows the input
signal to be attenuated while keeping the 50 ohm impedance level constant.
The program assumes the ideal case where all elements contain only their
specified characteristics.  For any input frequency, the real and imaginary
components of the input impedance are calculated and output.  The circuit
input VSWR and losses are computed, including any loss due to mis-match.
The calculations are made with RG as the generator drive source and RL as
the terminating load resistance.

NETFILE.1 consists of a three element matching circuit, a series tuned PI
circuit with a 10 ohm load.  It is resonant at approximately .5 GHz as a
frequency sweep (-1 at F0 prompt) will show.  It was designed to match a
5:1 impedance ratio, which is typical for bipolar power transistors.

NETFILE.2 uses three transmission stubs to match a transistor output to a
50 ohm load at 1 GHz.  A short 50 ohm line is followed by a double stub,
open-line section which resonates the circuit.  The shunt stub impedance
is chosen at 35 ohms to shorten its length.  The small inductance, Elem #1
represents the transistor output lead and the package bonding wires.

5. SUMMARY:    This program has been used to design and develop amplifier
and multiplier circuits for several years.  Filters, impatt diode and
tunnel diode amplifiers have been designed and analyzed while the program
was being developed.  Although a larger program, with lossy transmission
line capabitity would be an improvement, it is quite adequate for all but
the most difficult design jobs.

The program LOSSY, which is included with this group, will calculate line
loss and show the effect of changing loads on a given transmission line.
MICLINE and MSTRIP may be used when a circuit is designed by using micro-
stripline techniques.  MCOUP, MFILT, MULTI, PARCON and VSWR are part of
this group, also, and are useful in circuit design work from VHF to SHF.

These programs are placed in the public domain for non-commercial purposes
only and no other use may be made of them without the author's permission.
The author will not be liable for any problems from their use by others.



8-21-87                 James R. Wiley                     813-783-1257
                        1015 Mohawk St.
                        Z'Hills, FL  34248