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Your questions – our answers!

A high customer satisfaction is the central goal of the REEL GmbH. To us, this means to not only supply each customer with exactly the product he needs for their application, but also to provide advice and support in any aspect.  We regularly receive many questions regarding the topic of antennas and their application. Below, you will find answers to questions which reach us frequently:


1 - How can the different functions of an antenna with the same connectors be distinguished?

Following the FAKRA color scale, we use these shrink tubing colors: red for GSM, GPS for Blue, Yellow and White for WLAN, Bluetooth, Wimex. On request we can also use a color code you specify.

2 - What do the designations 2G, 3G, 4G and 5G mean?

Generation descriptions:

  • 2G = 900 and 1800 MHz Band
  • 3G = Quadband + UMTS
  • 4G = Quadband UMTS+LTE
  • 5G = latest generation from about 2020 (the frequencies are not fixed yet).

3 - Do REEL antennas require an additional ground plane?

With the exception of our PCB solutions, all REEL antennas have an internal mass and thus need no further mass to function. Mounting on a plastic or glass surface is possible, but installation on a metallic surface improves performance.

4 - How is the performance in the radiation patterns evaluated?

In order to compare antennas, we introduced our own standard. The cable has a length of 0.60 m without connectors. In the measurements for the general data sheets, an SMA (m) connector is used. Why? In order to calculate the power of an antenna at 900 MHz and a cable length of 3.00 m, you must subtract the cable attenuation pull of 2.4 m from the power at 60 cm (eg. +3 dBi).

An attenuation of 0.5 dB / m results in the following: + 3 dBi - (2.4 x 0.5) = + 1.8 dBi.

Therefore there is an antenna power of +1.8 dBi at 3 m cable length. As once again a connector is used (usually with similar attenuation values), one can ignore this, as it has already been measured.

5 - Where can I find technical information about the antennas?

The REEL configurator also offers as a function the creation of technical data sheets. Here the complete article number (note spelling!) has to be entered in the corresponding area at the bottom of the page. A corresponding data sheet in PDF format will be generated. If the desired data sheet cannot be generated, we are of course at your disposal. Please replace customer-specific endings with "XX", as these cannot be displayed.

6 - What effect does the cable length of the antenna have on the function?

Basically, it can be stated that the cable length has a greater influence at higher frequencies (e.g. WLAN) than at lower frequencies (e.g. GPS). With increasing cable length, the signal losses also increase, so that it is generally recommended not to specify cables longer than necessary. Accordingly, cable lengths longer than 10 meters are critical. For special applications also very low-loss cables can be used as adapter cables.

7 - What is the difference between the roof housings 70 and 71?

The outer dimensions of the two roof housings are the same. The new threaded base is equipped with a bayonet closure and is therefore stronger and more resistant to external influences than the previous plastic housings. In addition, this design offers more space inside, which allows us to use a board with higher isolation between GSM/LTE and GNSS/GPS. Depending on the application a thread length of 14mm, 17mm or 26mm can be chosen.

8 - May an antenna be mounted on all materials?

The installation is possible on all clean, stainless surfaces. No additional ground plane is required as the antenna has an internal ground plane.

9 - Is there a maximum torque when mounting the antenna?

When installing the roof antennas, it is essential to observe the maximum torque. The following torques apply for the different roof boxes:

  • Roof housing 70/71: min. 4 Nm to max. 6 Nm
  • roof housing 98: min. 4 Nm to max. 8 Nm

10 - What must be observed when installing adhesive antennas?

Before the adhesive pad can be applied, the surface must be cleaned thoroughly. For this purpose, use the cleaning cloth provided or a cleaner with isopropanol. The temperature during mounting should be >10° C.

11 - How long do I have to wait for an antenna after ordering?

The standard delivery time for antennas is about two weeks. REEL does not have any stock on hand, as all antennas are assembled according to customer specifications using the modular system but has sufficient raw material available.

12 - What does ECE-R 118 mean?

ECE-R 118 is a guideline that regulates the flammability of substances in vehicles used for passenger transport. REEL has had new materials certified according to ECE-R 118.03, so that the antennas can be installed in the interior of buses, for example. These antennas are given the suffix R118 after the article designation.

13 - What is the advantage of a MIMO antenna?

MIMO (Multiple Input Multiple Output) refers to a transmission method in which several receiving and transmitting antennas are used for communication. In practice, MIMO technology is often used in mobile communications and WLAN. For LTE, the method was introduced to receive two data streams radiated separately from the base station simultaneously, which ideally doubles the data rate. Due to the close proximity of the antennas in one housing, however, overlapping may occur. In this case the data rate is reduced, because the receiver has to capture both data streams separately and separate them cleanly in order to be able to process them further.

Your question wasn’t there?

Don’t hesitate to contact us and take advantage of our extensive technical expertise. At REEL we will find a solution for every individual requirement.

More questions? Just call +49 (0) 6441 - 671410 or e-mail