SuperNEC Newsletter - Sept 2004
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Use SuperNEC to simulate patches
SuperNEC was used to simulate a cluster of patches to determine the effect of the other patches on the radiation pattern of a single patch. The article below gives some of the results that was obtained.
A patch antenna operating
at 5.4 GHz was modeled numerically in SuperNEC and compared to measured
data. The numerical model of the patch was verified by comparing the
simulated and measured radiation patterns.
The E and the H-plane patterns of this patch were computed
and compared to the measured patterns. The comparison at 5.4 GHz is shown
below left. The main lobes of the pattern are faithfully reproduced,
however there appear to be errors in the back lobes.
To
understand the reason for these discrepancies it is necessary to study the
pattern measurement set up. The antenna nearest the camera (see the figure
above left) is attached to the rotator via an L-shaped string of
connectors (see above right). These connectors are certain to have an
effect on the back lobes of the radiation pattern, especially the H-plane
pattern as the connectors are parallel to the polarisation of the
antenna.
The SuperNEC model (above middle) shows the equivalent
SuperNEC model. It is very difficult to model the connectors in SuperNEC,
however this model is sufficient to illustrate the effect that the
connectors have on the back lobes of the antenna. The figures below shows
the improvement in the E-plane patterns. The pattern on the left is
simulated without the connectors and the shape of the back lobes is not
well reproduced. The simulated pattern on the right includes the effect of
the connectors and also faithfully reproduces the shape of the antenna
back lobes. The amplitude of the back lobes is not perfect, but this maybe
due to an inaccurate model of the connectors, or perhaps, the presence of
the fibreglass pole used to support the antenna.
The figures at the
bottom shows the improvement in the simulated H-plane patterns. Again the
all the features of the back lobes are reproduced when the connectors are
included in the SuperNEC model. The amplitude of the side lobes,
especially at phi equal to 90° and 270° have errors. The presence of the
fibreglass mounting pole may well account for these discrepancies.
The
SuperNEC model of the patch was successfully verified by comparing
measured and simulated radiation patterns. It was found that it was
necessary to model the L-shaped connectors at the back of the patch in
order to obtain reasonable correlation between the measured and simulated
patterns. The agreement between the patterns was not perfect, however it
was more than satisfactory to instil confidence in the numerical model of
the patch.
For more info on SuperNEC, please contact Renier.Dreyer@poynting.co.za.
Q: What is the difference between simulation and model frequency?
A: The simulation frequency or frequencies are the frequencies at which the problem will be simulated. The simulation frequencies are set under the “Simulation Settings” tab in SuperNEC.
The model frequencies can be thought of as the segmentation frequency. In other words this is the frequency which determines the length of the segments. This is set at the bottom left of the SuperNEC GUI. This should be set to the highest frequency at which you will be simulating the structure.
Q: Can SuperNEC be used to simulate patch or micro-strip antennas on a dielectric substrate?
A: SuperNEC can simulate patch antennas on an air substrate. SuperNEC can, however, not simulate patch antennas on a dielectric substrate. This feature will be included in a future release of SuperNEC.
Q: Can I write my own assemblies if I have the runtime version of SuperNEC?
A: To write your own assembly you will need Matlab’s script editor. The user can not write their own scripts with the runtime version of SuperNEC.
Q: I have formatted my hard drive and reinstalled SuperNEC. Why does my license no longer work?
A: When you format your hard drive the disk serial number changes. Your SuperNEC license is linked to your disk serial number. Once you have formatted your hard drive you will need to request a new SuperNEC license from supernec@poynting.co.za .
Q: Can SuperNEC import CAD files?
A: SuperNEC can not import CAD files directly. There is however a program within SuperNEC called SIG to create complex structures. The best way to create a complex structure from a CAD file is to create DXF cross sections from the CAD file. These cross sections can then be used as inputs for SIG.
Q: I want to create a ground plate on which I mount an antenna. How do I do this?
A: A ground that is limited in size can be created using “snplate”. A gridded ground is the best way to simulate a small ground plate. UTD plates need to be large with respect to wavelength and are typically only suited for scattering problems.
- Faster matrix fill time
- Simply Sparse 2
- The runtime version of SuperNEC will be replaced by a new deployable version of SuperNEC
- SIGGUI interface is to be updated and animated help included
- Animated help will be extended
- EM functions for manipulation of data is to be added
- New GUI features are to be added
ff
When installing wireless
electronics in combination with outdoor antennas you often require lengths
of low loss cable that dilutes the gain of your antenna. To overcome this
problem Poynting has developed the BridgePoynt range of products, that
consists of antennas integrated with WiFi equipment.
The WiFi
equipment is housed in weatherproof die-cast aluminium boxes behind the
antenna. The ergonomic die-cast housings allow easy access to electronics
using a single closing screw and a sturdy hinge. Almost zero cable losses
are incurred due to the close proximity of the WiFi radio to the
antenna.
The BridgePoynt equipment
is configurable as either an access-point or as a client all units will be
pre-configured as point-to-point bridges with full security which enables
a simple link without expert user configuration
knowledge.
Installation is simple: The units are mounted
outdoors facing each other in line-of-sight and the CAT5 Ethernet cable
supplied with each unit, is connected to computers and/or LANs at either
end. The BridgePoynt solutions are provided with Power over Ethernet (PoE)
injectors (no power supply cable is needed at the unit.)
The
BridgePoynt product is also sold without an integrated antenna, in which
case a bulkhead N-type female connection is provided for linking an
external antenna to the oudoor box.
Poynting will also supply the
BridgePoynt solution without internal electronics for clients who wish to
integrate their own WiFi equipment.
The range currently consist
of 4 variations:
BridgePoynt Box
- die cast box with electronics only.
3 km
BridgePoynt - 13 dBi antenna with electronic box.
10 km
BridgePoynt - 18 dBi antenna with electronic box.
BridgePoynt
Lite - 13 dBi antenna and electronics in one.
A 22 dBi antenna
with a reach of 20 km is under development. Poynting will mount third
party WiFi or other radio equipment in to the outdoor boxes for large
quantity orders. Poynting have also developed a 5 - 6 GHz BridgePoynt unit
with an integrated grid dish antenna sporting a gain of about 28 dBi!
BridgePoynt extremely cost effective given the saving in installation and
maintenance, as well as simplicity of logistics.
Please note
that all distances quoted above are applicable when 2 boxes of the same
gain are used together and assumes line of sight.
For technical
enquires call Anton Frolich (product manager) and for sales and
distribution call Claire Nitch or Louie van Wezel at (011)
262-5155.
Note: BridgePoynt
Lite
Available locally (SA) from Miro.
Dealers in other countries please contact Poynting.