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Apple Granted Patent for Signal Enhancing and Inductive Charging Docking Station

Posted Saturday, November 17, 2012 by Mike Cicero

An obvious trend in handheld electronic device designs is the increasing integration of wireless technologies and features for streamlining the user experience and de-cluttering work spaces. To accomplish this, wireless devices must incorporate one or more antennas to send and receive wireless signals. However, antennas are inherently susceptible to electromagnetic interference. Thus, electronic device designers are continuously searching for ways to reduce the negative effects of such interference.

Earlier this year Apple Inc. was granted U.S. Patent No. 8,207,906 (issued June 26, 2012) entitled “Antenna insert” which claims technology aimed at mitigating the problem of electromagnetic interference in handheld devices. The patent describes how the problem of electromagnetic interference is exacerbated by the combination of two design restraints. First, the average user desires to have full wireless capabilities available even which the device is connected to an external accessory such as a docking station. Second, the device designers aim to reduce human exposure to radio frequency energy emitted by the device antenna by locating the antenna as far as possible from the user’s brain, i.e. at the bottom of the device adjacent to where a docking station attaches to the device. Obviously, locating the antenna adjacent to a physical electrical connection, e.g. a combination data transfer and charging connection, where the electromagnetic field from the connection is strongest is not ideal from the standpoint of minimizing interference. Any smart phone user that has experienced there docking station speakers emit a strange sounding pattern of buzzing noises just prior to the phone ringing has experiences the effects of electromagnetic interference.

The “Antenna insert” patent goes on to disclose various technologies to “enhance the integrity of wireless communication with a handheld device when connected to an accessory,” and also “that at least some of these adapters and docking stations operate with a handheld device without using a physical connector.”

One feature emphasized in the disclosure is the use of reradiating radio frequency (RF) antennas. A reradiating RF antenna is a type of antenna that receives a radio frequency and retransmits it, preferably with enhanced signal strength. This feature improves performance by essentially overpowering the electromagnetic interference emitted by the physical connection.

In addition to reradiating antennas, another key feature of the disclosure is the use of inductive coupling to complete a charging circuit . Inductive coupling allows for the handheld device to be charged without the need for a physical connection. One common household example of this technology is the Sonicare® toothbrush charging station. People familiar with this toothbrush know that there is no physical connection between the battery and the charging station. This allows for the battery to be completely sealed within the toothbrush reducing both physical as well as corrosive wear on the electronic components. Obviously, this would benefit Apple’s handheld devices too.

Because any inductive charging unit inherently produces its own electromagnetic fields, care must be taken to minimize the interaction between the charging unit, the main antennas, and the reradiating antennas. In some embodiments, Apple mitigates this concern by dividing the time of operation between the features, e.g. the inductive charger only operates when the device is neither sending nor receiving a wireless RF signal.

While the benefits of this technology are quite clear, it remains unclear when Apple plans to make this technology available to the public. I can predict though that if Apple implements this technology with the superb packing design it has become known for the product will be an immediate success.

Apple Granted Patent for Signal Enhancing and Inductive Charging Docking Station ›› Ruttler Mills PLLC