Planar inverted-F antenna with a hollow shorting cylinder for internal mobile phone antenna

Planar inverted-F antennas (PIFAs) have been very popular as an internal antenna in small handheld wireless communication devices. Recently, in many wireless devices, a digital camera is embedded and is in competition with the PIFA internal antenna for the very limited space on the system circuit board. We propose a novel design of the PIFA with a large hollow shorting cylinder for application in a mobile phone with an embedded digital camera. The hollow shorting cylinder has a large diameter (8 mm in this case), and it is easy to fit the lens of a practical embedded digital camera inside it. In this case the proposed PIFA and the embedded digital camera together occupy a minimum space, and very small or negligible coupling effects of the embedded camera with the PIFA are expected. A design example of the proposed PIFA for application in a UMTS (Universal Mobile Telecommunication System, 1920-2170 MHz) mobile phone is demonstrated. The experimental results obtained are also presented.