The Bluetooth antenna is a key component that affects the transmission characteristics of the Bluetooth module. In a variety of different Bluetooth applications, the antenna design methods and materials used are different. Choosing an appropriate antenna can not only help match the product's appearance and improve the transmission characteristics of the Bluetooth module, but also further reduce the cost of the entire Bluetooth module.
1. Dipole antenna
Dipole antenna is a kind of Bluetooth antenna. The appearance of the dipole antenna is usually cylindrical or sheet-like. It has an adapter at the bottom of the antenna as an energy feeding device, and it is connected to the adapter of the external antenna of the Bluetooth module. Another way to connect the antenna is to use a rotatable adapter. The advantage of this method is that the antenna can be rotated at any angle according to the needs of use, thereby improving the transmission effect. But its disadvantage is that the cost of the rotatable joint is relatively high.
2. PIFA antenna
The PIFA antenna can reduce the sensitivity to the grounded metal surface in the module, so it is very suitable for the Bluetooth module external antenna. Since the PIFA antenna only needs to use a metal conductor to match the appropriate feed and the antenna is short-circuited to the ground plane, its production cost is low, and it can be directly welded to the PCB circuit board.
3. Ceramic antenna
Ceramic antenna is another miniaturized antenna suitable for Bluetooth devices. The types of ceramic antennas can be divided into block ceramic antennas and multilayer ceramic antennas. Using ceramics as the antenna medium can effectively reduce the size of Bluetooth antennas.