Golden Engineering
Golden Engineering
At Golden Engineering we are passionate about antenna simulation. On this last day of the year we want to give you our Log-Periodic Christmas Tree made with AN-SOF:
We thank all our clients, users and people who collaborate so that the AN-SOF Antenna Simulator project continues to grow day by day.
Happy New Year!
This version of AN-SOF has new functions and options:
Tip: double click on table items to instantly display plots.
REQUEST AN-SOF 7.90 TRIAL VERSION >
Enjoy AN-SOF!
This small transmitting loop antenna is 1 meter high above average ground, so the radiation pattern is not donut-shaped as expected for a small loop in free space. The value of the tuning capacitor is indicated for each resonance frequency.
Large loop: 70 cm in diameter, RG-8 cable.
Small loop: 15 cm in diameter, RG-6 cable. Inductive coupling between the feedline and the large loop, spacing of 2 cm.
The color scale on the loops indicates the current flowing for a reference voltage of 1 V.
Download the project files from this link >.
Go to AN-SOF main menu > Run > Run Bulk Simulation and select the five “.nec” files to run the calculations automatically. You can do it with the trial version of AN-SOF.
This Quadrifilar Helix (QFH) antenna can be used for signal reception from NOAA satellites. These are omnidirectional antennas made up of 4 wires with a helical shape. This design is about 0.14λ in diameter and the length of each helix is 0.4λ. It resonates at 137.5 MHz and has a bandwidth of 6% (SWR < 2). The purpose of the helices is to block surrounding interference.
In free space, the radiation pattern actually points downward when the coaxial cable (the source in the simulation) is connected to the top of the antenna. However, when a real ground plane is added and the antenna is placed 5 meters high, multiple lobes and a more omnidirectional pattern are obtained, as expected.
This Moxon antenna variant resonates at 145 MHz.
Input Impedance: 47 Ohm
Bandwidth: 7% (VSWR < 2)
Gain: 6.3 dBi
F/B: 19 dB
Beamwidth: 130°H / 80°V
This 4-element biquad array resonates at 434 MHz. The wires that connect the driven element to the reflector work as a two-wire transmission line that allows us to obtain an input impedance of 50 + j0 Ohm.
It may be noticed that the polar plots are on a log scale. ARRL-style log scaling is coming in the December release of AN-SOF!
This is a 4 element broadband directional antenna. More than 50 MHz of bandwidth (SWR < 1.5) around 285 MHz. Gain 7 to 8 dBi. Length 0.52 m and maximum width 0.6 m.
The driven element is shaped like a double arrow and has a folded parasitic element right in front of it.
Explore the new AN-SOF User Guide >, where you will find detailed information about its many features, as well as step-by-step examples and tips to help you quickly move forward with your antenna modeling projects.
From this link > you can download 5 examples of antenna models that have less than 50 segments, so the calculations can be run with the trial version of AN-SOF:
It is an array of two tightly coupled loops with a bi-directional pattern. Both loops are linked to share a single feed point. This antenna can operate in the 14 to 28 MHz bands with the appropriate impedance matching. It is self-resonant when the perimeter of each loop is around one wavelength. In this example, each loop is 3 x 4.5 m and the resonant frequency is 19.8 MHz.
A balun can be modeled in AN-SOF using an equivalent generator, as the figure below shows. Since voltage sources admit an internal impedance, we can adjust its resistive part to match the antenna input resistance.
This design is for 5 bands on a single pole. Each “J” corresponds to a band and therefore the feed point changes depending on the frequency. The resonance frequency is indicated in each case, which can be changed by moving the feed point. The height is about 5 m.
Enjoy!
Here is a relatively compact array of 5 square loops for 145 MHz. It does not need a matching network since the input impedance is practically 50 Ohm. Gain 12 dBi. Beamwidth 50 deg. F/B 20 dB.
These are compact, lightweight antennas that can be used for DX applications. This 2-element array is the simplest we can build to get a directional antenna using delta loops. It is practically resonant with 50 Ohm of input impedance near the band center. This is an example where we need to enable the Exact Kernel option in AN-SOF since we have sharp angles between wires.
Enjoy this new version!
This model is self-resonant (50 Ohm) in the analyzed frequency range, so it does not need a matching network. Adjust the indicated gaps to minimize the VSWR.
AN-SOF 7.10 is now available for download!
2-element quad antennas are very popular due to their compact size and gain similar to a more element Yagi. In addition, they can be designed to obtain an input impedance of 50 Ohm.
This design can operate at 27.5 MHz. We have added a script that allows us to plot the gain and front-to-back ratio as a function of element spacing. See this video >.
We can see that both cannot be maximized at the same time, but it is preferable to choose the maximum F/B since the gain changes relatively little.
To create the Scilab script, we started from a basic design in AN-SOF and then exported it as a *.sce file.
