The country’s patent office has granted a patent to Apple Inc for its invention regarding a compact tunable antenna used in mobile phones and other hand-held devices.
The invention titled Tunable antenna for hand-held devices pertains to a compact antenna. Apple claims that it contains integrated circuit technology advances as hand-held devices are shrinking in size, therefore triggering the need for small antennas.
Nirmalya Sinha, assistant controller of patents & design, Kolkata, granted the patent after finding all the requirements of the application having been addressed satisfactorily. The patent application was filed by Apple in 2009 based on an international application which derived priority from a US application in 2006. The filing in India was done in concurrence with the company’s plan to get the patent in as many as countries.
The patent filing mentioned Zhang Zhijun, a Chinese citizen and Caballero Ruben, a Canadian citizen, as the inventors. The first examination report (FER) was issued on February 20, 2014 and the response to FER was filed on January 15, 2015.
According to patent specifications submitted by Apple, antennas with tunable capacitive loading have been developed in an attempt to address the need for compact multi-band antennas. By varying the amount of capacitive loading that is applied to the radiating element, the resonant frequency of the antenna can be adjusted. This allows an antenna with a relatively narrow frequency range to be tuned sufficiently to cover more than one band.
A typical antenna for a hand- held device is formed from a metal radiating element. The radiating element may be fabricated by patterning a metal layer on a circuit board substrate or may be formed from a sheet of thin metal using a foil stamping process. These techniques can be used to produce antennas that fit within the tight confines of a compact mobile device. Modern hand-held electronic devices often need to function over a number of different communications bands.
For example, quad-band cellular telephones that use the popular global system for mobile (GSM) communications standard need to operate at four different frequencies (850 MHz, 900 MHz, 1800 MHz, and 1900 MHz). “Although multi-band operation is desirable, it is difficult to design a compact antenna that functions satisfactorily over a wide frequency range. This is because small antennas tend to operate over narrow frequency ranges due to the small dimensions of their radiating elements,” Apple said in its patent filing.
