home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
PC Electronic Plus
/
PC Electronics Plus (Most Significant Bits)(1995).ISO
/
nova
/
nova.doc
< prev
next >
Wrap
Text File
|
1993-10-06
|
9KB
|
160 lines
Dear Circuit Designer, Engineer or Student:
You have received "NOVADEMO", an RF circuits analysis program for the IBM
compatible computer. The disk you received has: a small working version of
"NOVA", a library of components, and files of sample RF and audio circuits.
"NOVADEMO" is limited to 10 nodes, but otherwise is functionally the same as
"NOVA-87". Math coprocessor is required. NOVA has all the following important
features:
1) Full screen circuit editing.
2) Nodal circuit notation.
3) Fast analysis.
4) Excellent graphics.
5) Time domain analysis.
6) Circuit Optimization.
7) Circuit tweaking.
8) Two port S-parameter devices.
9) Ease of use.
The price for NOVA is only $495.
You can order it from: Stanton Software,
414 Exton RoadHatboro, PA 19040
Phone 215-443-8382
NOVA Tutorial Copyright 1993 by Robert Stanton
General Information: NOVA is a program that can analyze most linear AC and RF
circuits. It will do: AC analysis, S-parameter analysis showing: S11, S21,
S12, S22, and group delay. Time-domain analysis (square wave input).
Optimization of AC and RF circuits. The component types available are:
resistors, capacitors, inductors, bipolars, FET's, op-amps, transformers,
transmission lines, and two-port devices.
Editing Screen Commands:
1) "F" Set analysis frequencies.
2) "S" Save a circuit on disk.
3) "G" Get a circuit from disk.
4) "N" Change the "output" node. (The node at which the voltage is shown.)
5) "Q" Change the parameters of the components.
6) "*" Clear editing screen, for a new circuit.
7) "+" Library of active components.
8) "A" Run analysis. A tabular output of S21 and S11 and group delay.
9) "J" Draw graph of S21 and S11, and/or phase, and/or group delay.
10) "W" Time domain analysis.
11) "`" Start Circuit Optimization.
12) "/" Set optimization objectives.
13) "E" Plot Smith Chart. (For RF circuits only)
14) Entering a number, will change the value of a component or node.
Graph Commands:
1) "S" Change the vertical scale.
2) "F" Change frequency sweeps.
3) "D" Parameters to be plotted may be selected.
4) "PrtSc" Prints a graph from the screen. See the Dos manual under
"GRAPHICS", for details of how graphs are printed, using the "PrtSc" command.
5) "N" Change the output node. Allows multiple plots on the same graph.
6) "Arrows" Circuit tweaking.
7) "C" Clears the screen.
8) "[" and "]" Marker, with tabular printout.
9) "Esc" Leave graph screen.
Getting Started:
1) Insert the NOVA demo disk.
2) Enter NOVADEMO The program will load and start running.
Example Circuits: The example files on the disk will demonstrate the features
and capabilities of NOVA. For comprehensive instructions see the written
manual.
Example (1) "RC" (Resistor and capacitor in series)
Pressing key "G", and then entering the file name "RC". Press key "J". After
the graph, of "RC" is drawn, press key "F". After the frequency screen comes
up, press the "Enter" key till the cursor comes to "Log steps". Enter the
number 100. The graph will be plotted with 100 frequencies logarithmically
spaced. Press key "D". Type "n" (no) at the phase prompt, and "y" (yes) at
delay and gain. The graph will then show the group delay and circuit gain.
Press key "S". Enter new values on "gain" scales. Press "Enter" till the
cursor goes back to the graph screen. When back at the graph screen, note that
the scales have changed. Now press key "A". The graph will autoscale back to
the highest and lowest values, for each parameter displayed. Press the "space"
bar or "Esc" key. Press key "A" for tabular results.
Example (2) "Ellipfilt"
This is an RF elliptical low pass filter. Because this is an RF circuit NOVA
will present the analysis in terms of S-parameters, rather then AC voltages.
Press key "J" for a graphically analysis. (* Circuit Tweaking *)To use the
"Tweaking" commands press the "up" and "down" arrow keys. Look on the bottom
of the graph screen and you will see it is selecting different components of
the filter. Touch the "left" or "right" arrow and the component value will
change.
Example (3) Quadhybd (Quadrature hybrid circuit)
This is a 90 degree quadrature hybrid transformer. It is an RF circuit that
works at 10.7 MHz. The circuit has an input port, and three output ports. Two
output ports are at a level of -3 dB, and a third port (called the isolation
port) is about -60 dB. The phase shift of one output port is 45 deg, and the
phase of the other is -45 deg. (at 10.7 Mhz only) At first glance it doesn't
look like this circuit would be good for anything. Actually, it is useful for
phase modulators and demodulators. Press key "J". To see the response at each
of the three output ports. Press key "N", then enter the number of the node
you want to have analyzed. The "N" (node) command works with the editing
screen and the graph screen. Using it while on the graph screen allows you to
plot multiple output ports on the same graph.
Example (4) TwoPort (MMIC device, MAR-1) (* Two Port, S-parameter component *)
A two-port data file is one of the programs most powerful analysis tools. A
file of a popular MMIC was created with a simple text editor, using a few
lines of S-parameter data from the manufactures data sheet. The analysis
produced by NOVA agrees with the measurements given by the manufacture. What
once was an extraordinarily difficult component to model, is now easy using
two port S-parameters. Press key "J".(shows S21, and S11) Press key "J" again.
(shows S12, and S22)
Example (5) Optcross (Midrange, 3.3 Octave, Audio Crossover)
A 3.3 octave, audio crossover was taken from a popular loud speaker design
cookbook. If you press key "J" you will see its' response has a hay stack
appearance. The filter was incorrectly designed by cascading a low pass and a
high pass. The correct way to design a bandpass filter, is to transform a
correctly designed low pass filter, into a bandpass. Nevertheless, this
filters' topology has some advantages over the topology of a "correctly"
designed filter. We wanted to make it flat from 200 Hz to 2 KHz, and have a
gain of 1 dB. To calculate the required values, from filter theory, is next
to impossible, and not only that, it would give you a headache. Here
optimization comes to the rescue. Given the correct objectives, the optimizer
will "fix" this filter. Press key "`". (It's in the upper left hand corner of
the keyboard) Let the program optimize until it stops by itself. (You can stop
it by pressing "Esc".) Good huh?
Example (7) Optellip
This is like the elliptical low pass filter in example 2, except the component
values are not correct for the goals. Press key "`". This filter, after
optimization, is very simular to an elliptical design. This is because the
goals were set to make a filter as ellipitcal like as possible. TLDC
(transmission line, directional coupler) He is an unusual circuit, a RF
directional coupler made up of only transmission lines. It only works near the
1/4 frequency of the lines. At that frequency, it is a true directional
coupler. By looking a the various ports you can see the directional
characteristics. TLBPF (transmission-line coupled, bandpass filter) Narrow
band RF filters are commonly made up of resonate circuits coupled by
capacitors or inductors. This filter is coupled by transmission lines. This
gives it better performance then a bandpass filter coupled by capacitors or
inductors. Of course, at low frequencies it could get very large. Actfilt This
is a dual amplifier audio bandpass filter. You will find that for this type of
filter to work properly, the unity-gain frequency of the op-amp must be much
higher then the passband frequency. If you wish to experiment, you may change
the unity-gain frequency of the op-amp with the parameter ("Q") command.(This
is a good audio bandpass filter circuit. It's stable and maintains a gain of
around 2, even with various types of op-amps.)
Limitation of Liability: NOVA is not warranted to meet your requirements nor
is the operation of the program warranted to be totally error free or
uninterrupted.In no event will there be liability for any damages, including
any lost profits, lost savings, or other incidental or consequential damages
arising out of the use, or inability to use, this program.
------------------------------------------------------------------------------.