With the development of modern science and technology, people have developed wireless charging for mobile phone, which greatly improves the convenience of mobile phone, but also can satisfy people’s vanity of showing off, so the market prospects are broad.
Wireless charging technology originates from radio power transmission technology, which can be divided into: low-power wireless charging and high-power wireless charging. Low-power wireless charging usually adopts electromagnetic mode, such as Qi standard for mobile phone charging, but ZTE’s electric vehicle adopts induction mode. High-power wireless charging often uses resonant power supply equipment to transmit energy to the power supply device, which uses energy to charge the battery, and at the same time for its own operation. Because the energy is transmitted by magnetic field between the charger and the electrical device, there is no wire connection between them, so there is no conductive contact exposing .
Wireless charging came into being in 1890, when physicist and electrical engineer Nicolas Tesla was studying the experiment of wireless power transmission and realized AC power generation.
By 2007, MIT’s research team published its articles on the American Science Magazine. The team used resonance to transmit electromagnetic waves and succeeded in “catching” them. Copper coils were used as electromagnetic resonators. One coil was attached to the transmitting side and the other to the receiving side. After the transmitter sends out a certain frequency of electromagnetic wave, the electromagnetic field diffuses to the receiver, and the power can be transmitted wirelessly.
In February 2014, computer manufacturer Dell joined the A4WP organization. At that time, senior manager of the group said that they would upgrade technology to support wireless charging to Super-books of computer manufacturers such as Dell. Before that time, wireless charging technology was only related to smartphones, small-sized tablets and other small mobile devices. However, A4WP, one of the three major wireless charging organizations, announced that its technical standards have been upgraded and the charging power has increased to 50 watts, which means that high-power devices such as laptops and tablets can also be charged wirelessly.
In October 2017, Apple’s three new mobile phones, iPhone 8, iPhone 8 Plus and iPhone X are all supported Qi wireless charging standards, which brings new directions of the mobile phone market.
There are three basic principles of wireless charging technology: electromagnetic induction, magnetic resonance and radio wave.
Electromagnetic induction mainly uses the principle of electromagnetic induction to produce a certain current on the secondary coil through a certain frequency of alternating current on the primary coil, thus transferring energy from the transmission end to the receiving end. At present, the most common wireless charging solution is electromagnetic induction. In fact, there is not much mystery in the technical implementation of electromagnetic induction solution. In December 2005, BYD in China applied for the patent of contactless induction charger which is used electromagnetic induction technology.
The principle of magnetic resonance is to adjust the transmitting device and the receiving device to the same frequency,so that they can exchange energy. A research team led by Marin Soljacic, a physics professor at the Massachusetts Institute of Technology, used the technology to light a 60-watt light bulb two metres away and named it WiTricity. The diameter of the coil used in this experiment is up to 50 cm, and it can not be commercialized. If the size of the coil is reduced, the receiving power will naturally decrease.
The advanced technology will lead the development of the industrial chain. The industry chain of wireless charging is divided into: receiving and transmitting. The receiving end upstream and downstream is divided into chips, magnetic materials, transmission coils, module manufacturing and system integration. The transmitter is divided into chips, coil modules, and design.
Receiver chip and system integration design link has high technical barriers and profits, which account for about 30% of the profits of the wireless charging industry chain. The main customers are mobile manufacturers. The development is very similar to fingerprint identification three years ago. Only IDT has production experience. Bloom customize that for Apple. A number of Chinese leading companies have develop the technology in advance, and the mobile phone receiver market has come to shape. Chinese brand Gionee M7 Plus chooses the wireless charging solution in China.
In the transmitter chip segment, there are a large number of participating companies and different levels. Front-line wireless charger manufacturers, such as Mophie, Belkin, Zebao pay more attention to the performance of repetition, FOD detection, and fast charging. Brand NXP, IDT and a few chinese manufacturers often become their preferred choice. Foreign chips are difficult to occupy a place in China because of high prices. Of course, the competition in this market is very fierce.
The outbreak of wireless charging market undoubtedly means huge business opportunities for upstream and downstream enterprises, not only in smart phones, but also in smart home, automobile and other markets. In addition, for the third party wireless charging providers, this also means huge business opportunities. These manufacturers provide wireless chargers not only for Samsung or Apple, but also for highly compatible products to charge different brands of mobile phones. However, the wireless charging industry is still in the early stage of development, and there are numerous wireless charger products appearing in the market. Only those products with good quality can stand out in the market.