Antennas comparison

This article provides the results of comparative analysis performed between four types of antennas, including the following:

- Antenna gain vs. standard. high-gain antenna.
- Antenna 900 MHz vs. 1800 MHz antenna
- Antenna with a horizontal beamwidth of 65 ° vs. antenna with a horizontal beamwidth of 90 °.
- Two antennas versus single band. dual-band antenna.


I. Settings
We compare the coverage areas of these antennas to determine the influence of high gain, dual-band and beam width.
The parameters were changed one by one, leaving the rest constant, so we could target them at the influence of this parameter.
Have used the following settings:
- A site.
- Three sectors (0 °, 120 °, 240 °).
- TX Power = 40 dBm.
- Antenna height = 30 m.
- Free space (for the calculation have not been considered or the spot and the clutter).
- It has been used a model of propagation at 900 MHz COST231 standard rate.
- It has been used a propagation model in 1800 MHz COST231 standard rate.
The legend of the map shown below describes the signal level shown in Figure 1.


II. Antennas
We compared the following antennas:

- 932DG65T2EKL 2 ° downtilt to 1810 MHz 18.0 dBi.
- DB858DG65ESY 0 ° downtilt 18.1 dBi at 940 MHz.
- DB858DG90ESY 0 ° downtilt 16.8 dBi at 950 MHz.
- DB932DG65EKL 0 ° downtilt to 1830 MHz 18.1 dBi.
- DBXLH-6565C-VTM 0 ° downtilt 17.0 dBi at 940 MHz.
- DBXLH-6565C-VTM 2 ° downtilt to 1785 MHz 18.2 dBi.
- UMWD-06519-2DH 2 ° downtilt to 1785 MHz 20.0 dBi.

 

 

 

 

 

 

 

 

  

 

 

 

 

 

 

 

 

 

III. Comparison of standard gain antenna vs. high-gain antenna
This analysis compares the 932DG65T2EKL antenna (gain 18 dBi) with the antenna UMWD-06519-2DH (gain 20 dBi). Both models have electrical downtilt of 2 and use the same frequency band (1800 MHz).
We can see that UMWD-06519-2DH provides better coverage. As this antenna has a gain 2dB higher, the average difference in the signal level of coverage is approximately 2dB. In the figure on the left, is the coverage of a standard gain antenna. In the right figure, we see the best coverage of high-gain antenna. There is a significantly greater area covered by the antenna
higher gain and the border area between sectors is also much better covered by the highest gain antenna.
This can pose a significant advantage for the 1800 MHz band, which has lower signal levels than the 900 MHz band is therefore very important to obtain the strongest possible signal to the output of the antennas, 1800 MHz and high-gain antennas can make it.

 

 

 

 

 

 

 

 

 

IV. Comparison of the frequency bands of 900 MHz vs. antenna. 1800 MHz antenna
This analysis compares the DB932DG65EKL antenna (18.1 dBi gain at 1800 MHz) with DB858DG65ESY antenna (18.1 dBi gain at 900 MHz). This comparison shows the influence of the frequency band in coverage since the antenna pattern and gains are very similar.
You can clearly see that the coverage area to 900 MHz is much greater and better coverage at 1800 MHz on average, the difference in signal intensity between these two antennas (and between 900 MHz and 1800 MHz) is between 8.10 dB at any location of that area.
This clearly shows that the signal levels at 1800 MHz require more attention than the signal levels at 900 MHz To override this influence, they often use different levels of tilt between the antennas of 900 MHz and 1800 MHz
NOTE: To calculate these values of signal level, standard parameters were used in 900 MHz and 1800 MHz


V. Comparison of the antenna of 65 ° HBW vs. the antenna of 90 ° HBW
This analysis compares the DB58DG65ESY antenna (18 dBi gain and 65 ° HBW) with DB858DG90ESY antenna (16.8 dBi gain and 90 ° HBW), in order to see how coverage is influenced by horizontal beamwidth (HBW) and also see how differences in income affect the coverage area.
We can see three effects:

a) The signal intensity in the area of the main lobe of the three sectors (0 °, 120 ° and 240 °) is slightly better with the antenna of 65 ° (about 1 dB) due to increased antenna gain of 65 °.
b) For the area between the sectors (in this case 60 °, 180 ° and 300 °) we notice a significantly better signal level of the antenna of 90 degrees about 2-3 dB higher because the beam width horizontal this antenna better covers the area.
c) The areas between the main lobe and the sector boundaries (about 30 °, 90 °, 150 °, 210 °, 270 and 330 °) are nearly identical coverage. Although the antenna of 65 ° is 1.2 dB more gain, this is offset by the higher horizontal beamwidth of the antenna 90.
These effects may be even more clearly by looking at the enlarged view shown below.


VI. Two vs single band antennas. Dual band antenna
This analysis compares the dual-band antenna DBXLH-6565C-VTM (gain 17 dBi at 940 MHz and 18.2 dBi gain at 1800 MHz) with two 932DG65T2EKL single-band antennas (18 dBi gain at 1800 MHz and DB858DG65ESY (ganancia18.1 dBi 900 MHz) to see what the difference is when using two single band antennas compared to a dual-band antenna.
You can see that coverage is very similar 900MHz, and that the single band antenna is about 1dB more intensity for most of the area because it has a higher 1dB gain (18.1 dBi compared with 17dBi), but this not a big difference.

Author:

Holger Raeder. Andrew Wireless Solutions