An RF module is a small electronic device designed to send and/or receive radio signals between two devices. In embedded systems, it is often desirable to communicate without wire with another device.
RF module is widely used in electronic design because of the difficulty of RF circuit design. Good electronic radio design is complex due to the need to achieve specific frequency operation. Moreover, reliable RF communication circuits require careful monitoring of the manufacturing process to make sure that RF performance is not adversely affected. Finally, radio circuits are often limited by radiation exposure and require certification and conformance testing by standardization organizations such as ETSI or the FCC. Thus, design engineers typically design a circuit for an application that needs radio communication and then “put in” a prefabricated radio module.
RF modules are most commonly used in consumer applications for medium and low-volume products such as wireless home automation systems, wireless alarm, monitoring systems, garage door openers, industrial remote controls, smart sensor applications.
Several carrier frequencies are commonly used in scientific and industrial ISM bands such as 433.92 MHz, 915 MHz, and 2400 MHz. Short-range devices can also use unlicensed frequencies such as 315 MHz and 868 MHz. These bands are lower than the current popular 2.4ghz band, so LoRa’s path loss attenuation is better. In addition, 868 and 900 MHZ have much less interference than the highly dense 2.4 GHz band. In addition, these low frequencies provide a lot of penetration in possible materials (brick walls, trees, concrete), so these bands lose less to obstacles than high bands.
RF modules can comply with defined protocols for RF communication, such as Bluetooth low power, Wi-Fi, and Zigbee, or they can implement proprietary protocols.
