How to Choose the Best Lora Antenna ?

How do I choose the best antenna for LoRa  application?

Antennas are a key part of the RF chip and are particularly important when choosing the best antenna for LoRa devices (such as LoRa nodes and LoRaWAN gateways) that transmit and receive data in the RF band.

The performance of the antenna occupies a particularly important position in LoRa IoT, and in practical applications, it is only known that LoRa antenna A has better performance and longer range than LoRa antenna B. It is not clear what causes LoRa antenna A to work better than LoRa antenna B, and thus there is no direction to choose in the application.

In the introduction of LoRa antenna in this paper, the basic performance of the antenna is affected by the following parameters: impedance, VSWR, gain, frequency, frequency bandwidth, and other parameters, what do these antenna parameters represent, and how to choose the best antenna for LoRa & LoRaWAN? The following is a brief introduction to a few different parameters.

Impedance

The input impedance of an antenna is the ratio of the input voltage to the input current at the feed side of the antenna. As most of the current market standards have an impedance value of 50Ω, this use is based on convention and custom.

VSWR

It is the reciprocal of the traveling wave coefficient and has a value between 1 and infinity. A VSWR of 1 indicates a perfect match. The VSWR of commercially available antennas is generally <1.5.

Antenna Gain

Antenna gain is used to measure the ability of the antenna to send and receive signals in a particular direction, it is one of the most important parameters for choosing a base station antenna. The higher the antenna gain, the better.

Frequency band

Lora antennas are available in several different bands, such as 169 MHz, 315 MHz, 433 MHz, 868 MHz, 915 MHz, etc. The application scenarios are different for different bands.

How do I choose the type of the best antenna for LoRa?

Once the Lora antenna parameters have been determined, then, we need to select the antenna type.

It can be understood that there are different antenna types on the market, such as Lora spring antenna, Lora fiberglass antenna, Lora magnetic antenna, Lora rubber duck antenna, flexible PCB/PCB Lora antenna, etc. When choosing an antenna, it is not the form itself that is important, but the parameters of the antenna and the site environment.

For example, the built-in antenna, subject to the size, generally with spring antenna, PCB antenna, FPC antenna. Of course, the antenna needs to be re-matched according to the structure and material of the housing.

And in the outdoor gateway, it is recommended to generally use a glass fiber Lora antenna, indoor nodes use a magnetic mount antenna, or rubber duck antenna is suitable.

For the best antenna for LoRa nodes, LoRa nodes generally pick spring antennas as most projects require a small structure for LoRa nodes in actual projects.

As for the best antenna for LoRaWAN gateways, there is generally no requirement for the size of the gateway in practical use, LoRaWAN gateways are generally not restricted by size, therefore, when selecting an antenna, it is recommended to use a fiberglass antenna.

When choosing an antenna, it is recommended to use a fiberglass antenna because it has good electrical insulation, good wave transmission, and better signal.
In addition, for outdoor LoRaWAN gateways, the environment is harsher, while fiberglass antenna has strong weather resistance, corrosion resistance, UV resistance, anti-aging, impact resistance, and still performs well in high temperature, low cold -45~110 degrees harsh environment, more suitable for a variety of complex environments, therefore, also makes people more inclined to choose the glass fiber antenna as the best antenna for LoRaWAN gateways.

What is the best antenna for LoRa outdoor use?

If you’re looking for a LoRa antenna to enhance your LoRa communication systems, you should definitely consider  LoRa fiberglass outdoor antenna, which has been specifically designed for use with LoRa radio bandwidths.

 What frequency does LoRaWAN use?

LoRa is digital wireless data communication IoT technology. LoRa transmits over license-free megahertz radio frequency bands: 169 MHz, 315 MHz, 433 MHz (Asia), 470MHz,  EU868 MHz, and US915 MHz. LoRa enables very long-range wireless data transmission.

How to select the best antenna for LoRa & LoRaWAN?

When selecting the best antenna for Lora & Lorawan applications, the shape of the antenna itself is not the most important. What is important are the parameters, the environment of the site, and the limitations of the structure.

Common LoRa antenna types include spring antennas, PCB, FPC, Ipex SMA antennas, and fiberglass antennas. Depending on the power and frequency size of the LoRa module, different antennas can be selected to match.

For a 100mW LoRa module, you can choose a spring antenna, PCB antenna, or FPC antenna.

Above 500mW module can choose SMA rubber duck antenna.

Above 2W module can choose the magnetic mount antenna, glass fiber antenna.

LoRa antennas generally have a range of frequency bands that they support, if used outside the band, the antenna performance will be degraded to a certain extent. Therefore, when using, you should try to make the device work in the frequency band supported by the antenna, in order to achieve the best transmission effect.
Generally speaking, the gain of the fiberglass antenna is higher than that of suction cup magnetic mount antenna; the gain of suction cup magnetic mount antenna is higher than that of rubber rod antenna; the gain of rubber rod antenna is similar to the PCB antenna and FCB antenna, but higher than the spring antenna.

In a communication system, the strength of the gain will interfere with the ability of the antenna to radiate or receive wireless signals; all things being equal, the higher the gain, the further the wireless signal will travel. Therefore, to improve the communication distance of the wireless module, it is also a good idea to choose a high gain antenna.

How do you mount a LoRa antenna?

1. For the best antenna for the Lora fiberglass antenna, possible to place the fiberglass antenna on the fixing u clamp bracket mount the fix u clamp bracket kit to the top of the pole or tower then connect the n-type female jack to the antenna.

2. For the Lora fiberglass antenna and rubber duck antenna, you can mount the antenna to the magnetic base mount, or directory mount the Lora antenna to the terminal.

3. Place the antenna off the ground as far as possible, do not touch the antenna with your hands when testing, the antenna is more than 2m from the ground and the human body is more than 2m from the antenna.

4. Don’t place the antenna near large metal objects, don’t place it by the river, minimize the obstacle between the antenna.

5. Keep the antenna upright, not flat on the ground, not skewed, try to keep both antennas on a horizontal plane.

The Lora antenna should be mounted as far away from the ground as possible, and not near large metal objects.

In addition, the actual frequency band used by the LoRa antenna should be the same as the frequency band range supported by the LoRa antenna.
For example, a 915 MHz antenna should be used in the 915 MHz band. If the 915 MHz antenna is used in the 868 MHz band, the results will be poor. However, if that Lora band contains both the 915 MHz and 868 MHz bands, e.g. 850-930 MHz Lora wideband, then both the 915 MHz and 868 MHz bands will work well.

Finally, attention needs to be paid to the antenna feeder cable assembly of the antenna, SMA to N adapter cable, the length of the magnetic antenna cable, etc. Especially if the cable length is long, the attenuation effect of the wire on the signal needs to be fully considered.