Free from the constraints of wires and charging pads, radio frequency makes wireless charging more flexible

Mark Hopgood, Senior Director of Corporate Strategy, Dialog

Wired charging is the mainstream charging method for mobile devices nowadays. Its charging and fast data transmission features have made both Apple and Android continue to adopt this technology. However, since this method will limit the device to a specific transmission interface, some manufacturers have always been optimistic about the future of wireless charging. Mark Hopgood, senior director of corporate strategy at Dialog Semiconductor, pointed out that after Apple included wireless charging function in iPhone X, iPhone 8, and iPhone 8 Plus in 2017, the overall market began to become active.

Mark Hopgood said that after WPC formulated the wireless charging standard Qi in 2010, the technology has been widely anticipated by the market, but the cost, safety and convenience have not been resolved, and the mobile phone manufacturers have not taken active actions, so the market has stagnated in the past few years. However, this dilemma has been broken by the introduction of the new generation of iPhones in 2017. For example, Dialog has recently received more and more market inquiries for its wireless charging technology.

Dialog's recent wireless charging layout is to cooperate with the startup Energous. Mark Hopgood pointed out that the near-field radio frequency wireless charging technology developed by Energous has passed the FCC certification in 2016, and its safety and non-interference have been recognized; its mid-field radio frequency wireless charging technology has also passed the FCC certification in December 2017. For Energous, the cooperation with Dialog can use Dialog's resources in the semiconductor field to solve its mass production and manufacturing problems. For Dialog, it has become the exclusive global supplier of Energous' WattUp wireless charging chips, which is a win-win situation.

Mark Hopgood further stated that there are currently two main wireless charging technologies, including inductive and resonant. Both methods require the coils at both ends of the transmitter and receiver to fit closely together to achieve charging efficiency. Energous' WattUp uses radio frequency wireless charging technology to allow mobile devices to receive radio waves from the transmitter and then convert them into power, thus eliminating the traditional coil design that takes up a lot of space.

In addition to the coil design, Mark Hopgood believes that WattUp's printed circuit board antenna is not only smaller in size, but also more flexible in design. In addition, its receiver can be designed in different distances according to the application field, including 5 cm contact near field, 90 cm mid-field, and 450 cm far field, making the application more flexible.

Mark Hopgood finally said that wired charging is constrained by wires, and inductive and resonant charging also need to be fitted with a charging base. Under these technologies, devices must accommodate the power generation end when charging. Radio frequency wireless charging technology can get rid of the constraints of wires and charging bases, making the use of devices freer and more flexible. However, Mark Hopgood also pointed out that the three wireless charging technologies of induction, resonance and radio frequency have their own strengths in cost, scalability, power, efficiency, size and distance, and the corresponding market applications are also different. Therefore, there is no problem of replacing each other, and they will coexist in the market in the future. Dialog will continue to cooperate with Energous to strengthen its layout in this market.