A new Apple patent (number 7999748) has appeared at the US Patent & Trademark Office showing that Apple is considering integrating cellular antenna under the keys of its laptops and wireless keyboards.
Per the patent, key antennas are provided for an electronic device such as a laptop computer. The electronic device may have radio-frequency transceivers that transmit and receive signals using the key antennas. An antenna resonating element may be mounted beneath a keycap of each key antenna. The antenna resonating element may be spirally wrapped and integrated into the keycap. The key antenna may function as an antenna and may also function as an input key for an electronic device.
A flexible communications path may pass through a hole in a conductive housing of the electronic device and may be used to couple the antenna resonating element to the radio-frequency transceiver. The antenna resonating element may be coupled to the radio-frequency transceiver by a weak spring. The weak spring may form a portion of the antenna resonating element.The inventors are Chris Ligtenberg, Brett Degner and Douglas Kough.
Here’s Apple’s background and summary of the invention: “It may be desirable to include wireless communications capabilities in an electronic device. Electronic devices may use wireless communications to communicate with wireless base stations. For example, electronic devices may communicate using the Wi-Fi (IEEE 802.11) bands at 2.4 GHz and 5.0 GHz and the Bluetooth band at 2.4 GHz. Electronic devices may also use other types of communications links.
“Many popular housing materials for electronic devices such as metal have a high conductivity. This poses challenges when designing an antenna for an electronic device with this type of housing. An internal antenna would be shielded by a high-conductivity housing, so internal antenna designs are often not considered practical in electronic devices with conductive cases. On the other hand, external antenna designs that permanently protrude from a device’s housing may have an unattractive appearance. Conventional protruding antenna designs may also be susceptible to damage. It would therefore be desirable to be able to provide improved antennas for electronic devices.
“An electronic device may have a keyboard. One or more of the keys of the keyboard may be key antennas. For example, one of more of the keys of the keyboard may have antennas integrated into their structure to provide the electronic device with wireless communications functionality.
“A key antenna may have an antenna resonating element. The antenna resonating element in the key antenna may be formed using any suitable antenna design. For example, the antenna resonating element may be formed from a flex circuit containing a strip of conductor, a piece of stamped metal foil, a length of wire, etc. The antenna resonating element may be mounted to the underside of a keycap of the key antenna. The antenna resonating element may be integrated into the keycap of the key antenna. The keycap may have a representation of the function of the key. For example, the keycap may indicate to a user that the key is a caps lock key.
“The electronic device may have a conductive housing. The key antenna may have improved transmission and reception efficiencies when the key antenna is away from the conductive housing of device 10. For example, the key antenna may have improved transmission and reception efficiencies when the key antenna is not being pressed by a user. In this position, the key antenna’s performance may be enhanced by the increase in separation (e.g., compared to the position when the key is pressed) between the antenna resonating element in the key antenna and the ground plane of the conductive housing of the electronic device.
“The key antenna may also have an indicator light. The indicator light may include a light source that illuminates a translucent portion of the keycap. The electronic device may use the indicator light to indicate a state of the electronic device that is controlled by the key. For example, the indicator light may indicate whether the caps lock function is active. The indicator light may switch on or off when the user presses the key. With another suitable arrangement, the indicator light may switch on while the user is pressing the key and switch off when the user is not pressing the key.
“The electronic device may have a radio-frequency transceiver. The radio-frequency transceiver may be coupled to the antenna resonating element in the keycap of the key antenna. The antenna resonating element may be coupled to the transceiver through a weak spring that flexes as the key is pressed by a user. The antenna resonating element may be coupled to the transceiver through a flexible communications path that flexes into the electronic device as the key is pressed by the user.
“The electronic device may provide wireless communications capabilities to otherwise non-wireless devices. The electronic device may also provide keyboard input for non-wireless devices. For example, the electronic device may be coupled to a non-wireless device through a wired universal serial bus interface. The electronic device may provide the non-wireless device with wireless communications capabilities when the radio-frequency transceiver in the electronic device is coupled to the non-wireless device over the wired interface.
“The electronic device may provide keyboard input for wireless devices and may extend the wireless capabilities of the wireless devices. For example, the electronic device may wirelessly couple to a wireless device to provide the wireless device with keyboard input capabilities. The electronic device may support wireless communications in additional radio-frequency (RF) bands that are not supported by the wireless device. The electronic device may extend the wireless communications capabilities of the wireless device to include the additional RF bands by relaying wireless communications for the additional RF bands through one or more RF bands that both the electronic device and the wireless device support.”
— Dennis Sellers