 | ANTENNA MODEL
runs under most Microsoft 32-bit Windows operating systems—Windows 98/ME/NT4SP6/2000/XP/XPx64/Vista/Vistax64.
(Windows 95 is not supported. Windows NT4
should have Service Pack 6
installed.)
Microsoft is shipping Windows
Vista without WinHelp. Antenna Model's context-sensitive "F1 / What's
This?" help popups are not available under Windows Vista unless you
download and install the missing WinHelp, available from the Microsoft
Download site
here.
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| ANTENNA MODEL
can analyze most wire antennas in free space, over perfect ground, or over
real-world grounds with the conductivity and dielectric constant you
specify. You describe the antenna to the program in easy-to-use
spreadsheet-style input windows, and then with one click of the mouse
ANTENNA MODEL
solves for
 | antenna currents |
| input impedance |
| power input |
| efficiency |
| gain |
| main lobe beam width |
| side lobe levels |
| front-to-back ratio |
| front-to-rear ratio |
| standing wave ratio |
| far field polarization in the
direction of the major lobe |
| traditional 2D azimuth and
elevation patterns |
| true 3D radiation pattern
|
|
| There are no built-in limits to
the number of segments, wires, sources, loads, or ground media that can be
modeled. Your models can have as many segments as you need,
limited only by the amount of real and virtual memory available on your
computer.
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| When antennas are modeled
over a
real ground, the
real ground may be represented by the MININEC ground model, the
Reflection Coefficient ground model, or the Sommerfeld-Norton ground
model. The Reflection Coefficient and Sommerfeld-Norton ground models are
equivalent to those of the same name found in NEC-based antenna modeling
programs. (ANTENNA
MODEL's implementation of Sommerfeld-Norton
ground is accurate for wire segments down to about 0.02 wavelengths above
ground.)
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| A frequency scan capability graphs
gain, standing wave ratio, front-to-back ratio, front-to-rear ratio, and
input impedance over the frequency range of the antenna.
|
| Traditional 2D azimuth and
elevation patterns can be plotted in polar coordinates with a log-periodic
power scale, or rectangular
coordinates with a linear power scale.
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| Up to three 2D azimuth and
elevation patterns can be plotted at once (overlaid) for easy comparison.
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| A true three-dimensional (not a wire frame) far
field pattern may be displayed, along with the average gain over the
surface of the solid figure. When the antenna is modeled in free space
or over perfect ground, the average gain can be used as an indication of
the validity of your model.
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| Far field patterns may be resolved into
equivalent horizontal and vertical linearly polarized components,
or left and right circularly polarized components.
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| Far field pattern data
points may be saved as an OpenPF data file.
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| Electric and magnetic near field
intensities can be calculated, at selected points in space, when the
antenna is modeled in free space or over perfect ground.
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| Electric far field intensities can be
calculated at selected points in space for any environment.
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| The reference antenna used for calculating
antenna gain may be an isotropic radiator or a half-wavelength dipole.
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| Sources may be defined as voltage sources
or as true current sources.
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| Loads and sources may be placed at a wire end or
a wire center, and they will always stay there.
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| Loads may be defined as series or parallel
combinations of actual components—resistors, inductors, and capacitors.
There is no need for S-Parameters.
|
| Wire resistance at the operating frequency (skin
effect is taken into account) can be modeled for a variety of common
conductor materials. You may also specify a "custom" wire conductivity
and permeability. Every wire can be made of a different material, if
desired. For antennas with heat losses, the efficiency of the antenna is
calculated.
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| A "Data Good" status bar display lets you
know if there are any problems with the antenna's definition. When the
Data Good indicators are all green, the Calculate menu becomes
active and you can begin to analyze the antenna.
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| A Symbols window with
formula evaluation capability does any mathematical calculations that
might be needed to define an antenna. You can define symbols using common
math and trigonometry functions. These symbols are then used in other
input windows to define the antenna. Want to change the tilt angle of a
rhombic? Just change the symbol that represents the tilt angle, and all
the rhombic dimensions will be recalculated for you instantly.
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| A Coil Wizard calculates
the inductance, distributed capacitance, radio frequency resistance, and
self-resonant frequency of single-layer air-wound coils. Equivalent circuits are
generated that you can insert into your model to represent the coil and
its leads.
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| A Clamp Wizard calculates
the equivalent diameter of a Yagi element where it is clamped. The clamp
may be a flat plate, angle stock, channel stock, or Hy-Gain clamp.
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| A Match Wizard designs
Gamma, T, Hairpin, or Beta matches for Yagi antennas. The matching device
can then be inserted into your Yagi antenna model. This wizard will also
design a Gamma match for a grounded tower.
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| A Yagi Optimizer
finds sets
of Yagi dimensions that satisfy performance objectives you specify.
Usually many slightly-different solutions can be found that satisfy the
requirements. One might have an unusually low standing wave ratio across
the band. Another might have the forward gain peaking in the part of the
band where you like to operate most. Still another might have an
exceptional front-to-rear ratio across the band. You can pick the solution that appeals to you the most.
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| ANTENNA MODEL
can be used as the calculating engine in Dan Maguire's
MultiNEC workbook
for Microsoft Excel.
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| ANTENNA MODEL
can import NEC-2 text files with an 'nec' file extension. CE, CM, EN, EX,
FR, GA, GC, GD, GH, GM, GN, GR, GS, GW, GX, LD, and RP 'cards'
(commands) are imported. RP cards are processed only for their ground
information. NEC-2 cards can quickly and easily construct tedious
structures like loops, wire grids, and elevated radials.
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| ANTENNA MODEL
can import antenna files in the EZNEC®
(*.ez) file format. (Transmission lines and wire insulation are ignored
and not imported.)
|
| A simple Calculator is
included, with a key for the velocity of light.
|
| ANTENNA MODEL
can be run unattended by means of DOS batch
files. Large antennas can be run overnight, or while you are away doing
something else.
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| The
ANTENNA MODEL
log can be saved as a text (.txt) file. All other output windows can be
saved as a bitmap (.bmp), GIF (.gif), TIFF (.tif), or JPEG (.jpg) image file.
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| A frequency scan graph's data points can be
exported to a text (.txt) file. The data points can then be imported into
a MathCad(R) Input Table or into a spreadsheet.
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| The SWR, Rin, and Xin graphs’ data points can be
exported to a comma-separated-values (.csv) text file. These data points
may then be imported from the text file into a spreadsheet, such as Dan
Maguire's ZPlots.
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| An antenna’s 3D pattern can be exported as an
IONCAP/VOACAP Type 13 gain table. The IONCAP/VOACAP propagation prediction
programs are used to select the proper antenna for a proposed
communications circuit. (The antenna must be over real or perfect ground,
and the center frequency must be between 2 and 30 MHz.)
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| The Rin and Xin graphs' data points can be exported
to a winSmith 2.0 Settings file. The data points are then imported from
the Settings file into the winSmith program. The winSmith program's
built-in Smith Chart can then be used to graphically design a matching
network. No mathematical calculations are required. (The winSmith 2.0
program is available from SciTech Publishing
here.)
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| Documentation is provided in two forms—an HTML Help
file, and an Adobe Acrobat PDF file. The HTML Help file is for use while
ANTENNA MODEL
is running. The Acrobat PDF file is more suitable for printing and
studying away from the computer.
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| Forty sample antennas are included. |
