How do I choose a best antenna for LoRa nodes and LoRaWAN gateways?

2022-12-09

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.

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, we need to select the antenna type.

It can be understood that there are different antenna types on the market, such as the 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 important not to the form itself but to 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, and 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 use a glass fiber Lora antenna; Generally, indoor nodes use a magnetic mount antenna, or a 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 a better signal.

In addition, for outdoor LoRaWAN gateways, the environment is harsher. At the same time, fiberglass antenna has strong weather resistance, corrosion resistance, UV resistance, anti-aging, and impact resistance, and still performs well in high temperatures, low cold -45~110 degrees harsh environments, 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 Kexin wireless LoRa fiberglass outdoor antenna, which have been specifically designed for use with LoRa radio bandwidths (850MHz – 930MHz).

Kexin wireless provides the 3dBi LoRa fierbglass antenna, 4 dBi LoRa antenna, 5dBi LoRa antenna, 5.8 dBi fiberglass antenna, 6dBi LoRa antenna, 8dBi LoRa antenna, 10 dBi LoRa antenna, 12 dBi LoRa antenna, 15dBi LoRa antenna, 20dBi LoRa antenna, etc.

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), UE868 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 site’s environment, and the structure’s limitations.

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

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.

The above 2W module can choose the magnetic mount antenna and glass fiber antenna.

LoRa antennas generally have a range of frequency bands that they support. The antenna performance will be degraded to a certain extent if used outside the band. Therefore, when using it, you should try to make the device work in the frequency band supported by the antenna to achieve the best transmission effect.

Generally speaking, the gain of the fiberglass antenna is higher than that of the suction cup magnetic mount antenna; the gain of the suction cup magnetic mount antenna is higher than that of the rubber rod antenna; the gain of the 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.

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