Users will be concerned to know the operating range of the equipment, and this is an important issue for equipment manufacturers as well.
You may want to suggest a long operating range in the specification, but it is no good if the user comes to view this specification with suspicion when actually using the equipment. Therefore it is necessary to include a disclaimer such as "Communication range varies according to the environment of use." The range shown in the specification of the radio module itself is only a guide, and when choosing a radio module it is necessary to test it using an actual evaluation board.

Receive sensitivity
The difference in communication range within the limits of the stipulated output indicates the good and bad points of the performance of the module. Communication range varies according to a number of conditions so sometimes it may not be included in the specification, however receive sensitivity is always included so we will compare the two.

Difference due to frequency
Communication range differs according to the frequency used. The higher the frequency of the radio wave, the higher its straightness and the less far it travels. 400 MHz radio waves are subject to the diffraction phenomenon and travel further than straighter 2.4 GHz radio waves.

Difference due to modulation system
ASK is more affected by background noise than FSK or PSK, and even if the radio wave reaches the receiver, data errors may occur.

Increasing the operating range:
Using a gain antenna
With receive only equipment, you can choose any kind of antenna. You can expect to increase the range if you use a gain antenna with good performance. Please conduct field testing with a number of antennas before selecting one. The integral and dedicated antennas used in CE approved radio modules are calibrated for transmission output in conformity with the specification, and should not be replaced for trivial reasons.

Careful design
When using a radio module, it is important that your design does not in any way degrade the receive sensitivity that is shown in the specification. It is also important to make every effort to avoid errors. Please pay attention to the following points.
* Ensure that the radio module is not subject to noise from the CPU or other devices in the system in which it is incorporated.
* Reduce noise coming from the system's control switch and the like.
* Make the position of the receiver a place where there is a minimum of noise.

* Take care in attaching the antenna.

Prev:How to Build a RF Transmitter Receiver

Next:What is the Modulation and Demodulation?

Leave a message

Message List

Comments Loading...

Products Category

Products Tags

Fmuser Sites

What is the RF range?

Leave a message

Message List