Introduction of True Wireless (TWS) Bluetooth Headset Antenna
In recent years, the true wireless (TWS) Bluetooth headset market has been extremely hot, and various mobile phone manufacturers have launched their own TWS headset products; it is enough to show the importance attached to this market. In the last article, we introduced the charging pin of the charging compartment of the true wireless (TWS) headset. Today, we will briefly introduce the antenna part. We will discuss the importance of the antenna in the TWS headset, the introduction of the Bluetooth antenna of the TWS headset, and how to choose three when designing the TWS headset. In one aspect, share the role, types, and design choices of the TWS headset Bluetooth antenna.
The Importance of TWS Headphone Antennas
From old-fashioned radios to current smart speakers, from "big brothers" to smartphones, from traditional Bluetooth headsets to TWS true wireless headsets. In the development of consumer electronics technology, the antenna is an important firmware. With the birth of the concept of the Internet of Everything, the role of the antenna is even more important for smart homes, smart vehicles, and smart wearable devices to be connected and controlled by one machine.
TWS earphones are True Wireless Stereo earphones. The main use method is to connect with mobile devices such as mobile phones and computers through Bluetooth radio frequency and then transmit audio information to the earphones, and then decode and output them on the earphone end. In this process, the Bluetooth antenna is required to act as a "tower" to communicate between the two parties and perform the tasks of sending and receiving. Therefore, in the TWS headset, the Bluetooth chip and the Bluetooth antenna complement each other, to realize wirelessly transmitted music playback and avoid the shackles of wires.
TWS headset Bluetooth antenna introduction
As an important firmware of the TWS headset, the current development of Bluetooth antenna is relatively mature. There are mainly four types of PCB on-board antenna, FPC, ceramic, and LDS. Consider the appearance of the TWS earphone product, frequency band requirements, and cost to choose the most suitable antenna type.
1. PCB on-board antenna
As the name suggests, the PCB onboard antenna is a type of antenna that is directly drawn on the PCB board. It is widely used in single-frequency module circuit boards such as Bluetooth modules, WIFI modules, and ZIGBEE modules. In TWS earphones, due to the limitation of volume, the application of the onboard Bluetooth antenna is relatively rare.
PCB onboard antennas can be designed and implemented by suppliers of PCB boards, which are equivalent to the circuit part of the board.
Advantages: The PCB onboard antenna does not need multiple debugging, and can be directly drawn on the PCB without cost.
Disadvantages: The required area is large, the directionality is relatively single, only suitable for a single frequency band, the consistency of different batches of antennas is relatively poor, and the anti-interference ability is poor.
2. FPC antenna
The FPC antenna evolved from the PCB onboard antenna. Due to the volume limitation of the TWS headset, the space on the internal motherboard cannot accommodate the antenna. The FPC antenna is equivalent to taking the antenna circuit out of the PCB and using other external metals to make the antenna a separate component. So that it can be better placed in the internal space of the TWS headset.
FPC antenna can be realized by PCB board factory of the soft board and flexible material.
Advantages: Applicable to most small electronic products, the frequency bands that can be made are also rich, the performance is better, and the cost is lower.
Disadvantages: Each product needs to be individually debugged and manually patched.
3. LDS antenna
The LDS antenna is a further upgrade of the FPC antenna. Although the FPC antenna has been able to use the internal space of the headset to a great extent, it still needs a flat plane to attach it.
The LDS antenna uses laser direct molding technology, which uses laser technology to directly form metal antenna patterns on brackets, cover plates, etc., which can be lasered to the irregular surfaces inside the earphones, further utilizing the internal space of the earphones.
Manufacturers of LDS antenna for laser processing, laser technology, and electroplating technology can support it.
Advantages: All directions can be supported and have strong acceptability.
Disadvantages: The cost is more expensive, and there are special requirements for the material of the outer surface of the product.
4. Ceramic antenna
The ceramic antenna is another antenna product that is widely used in Bluetooth module devices. It is named after the use of ceramic shells. It is mainly divided into two types: block ceramic antenna and multi-layer ceramic antenna.
The block ceramic antenna is to print the metal part of the antenna on the ceramic fast surface, and the multi-layer ceramic antenna can be printed on each ceramic dielectric layer according to the design requirements, thereby reducing the size of the antenna.
Advantages: small size, easy application, low cost, good performance, and only taking up a small space.
Disadvantages: The requirements for the clearance area are relatively high, the directionality is relatively single, and there are requirements for the placement position.
We learned from the previous dismantling of TWS earphones that due to volume limitations, PCB onboard antennas are relatively rarely used in TWS earphones. Choose according to the needs of your products, there is no fixed type of use.
How to choose the right antenna
Theoretically speaking, in terms of cost, PCB and FPC antennas cost less, ceramic antennas are moderate, and LDS antennas are more expensive; and in terms of space utilization, LDS antennas are the most flexible and can make full use of the internal space of the headset.
In terms of performance, the sending and receiving capabilities of external antennas are generally better than those of built-in antennas. TWS headsets are designed with built-in antennas due to volume constraints and portability requirements. The performance is relatively similar, and it is necessary to comprehensively consider a variety of factors to select a suitable antenna.
The design of the Bluetooth antenna of the TWS headset affects the transmission quality of the Bluetooth communication, which in turn affects the actual user experience. The selection of Bluetooth antennas is affected by many factors such as performance, frequency band, cost, and use space. Only by considering the specific product conditions and usage scenarios, and choosing a suitable antenna, can the maximum performance of the product be exerted.