Conventional Mobile Phone Research Articles

Internal multiband loop antenna for GSM/DCS/PCS/UMTS operation in the small‐size mobile device

AbstractAn internal multiband loop antenna suitable for application in the small‐size mobile device (groundplane length 50 mm only) is presented. Along the loop strip of the antenna, it is configured to have two symmetric meandered sections and a central widened section. With the configured loop strip, three resonant loop modes (0.5‐, 1.0‐, and 1.5‐wavelength loop modes) can be excited to form two wide operating bands centered at about 900 and 1900 MHz for GSM/DCS/PCS/UMTS operation in the small‐size mobile device. In addition, the loop antenna along with the short ground plane studied here shows near‐omnidirectional radiation patterns in the azimuthal plane for frequencies over the antenna's two wide operating bands, which is different from conventional internal mobile phone antennas and is advantageous for practical applications. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1279–1285, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23337

Internal multiband printed folded slot antenna for mobile phone application

AbstractA novel printed folded slot antenna suitable for GSM/DCS/PCS/UMTS multiband operation in the mobile phone is presented. The proposed slot antenna has a planar configuration and is easy to fabricate by printing on the system circuit board of the mobile phone. The slot antenna has a length of 106 mm and is folded into a compact structure with its two slot ends facing toward each other. This configuration allows the antenna to occupy a small area of 21 × 45 mm2 centered on the top portion of the system ground plane. By feeding the slot antenna using a 50 Ω microstrip line printed along the centerline of the system ground plane, two wide bands (the half‐ and one‐wavelength modes) of the antenna can be generated, with the lower band covering GSM operation and the upper band covering DSC/PCS/UMTS operation. In addition, small excited surface currents in the system ground plane are observed, and the antenna's two operating bands are in general not sensitive to the ground‐plane length variations. These features are attractive for practical applications and different from those of the conventional internal mobile phone antennas. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1833–1837, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22602

EZ M-Parking System

M-commerce has been applied in parking payment systems since 2001. However, its complicated user interface increases time for motorists to complete transactions and, therefore, hurts the popularity of mobile phone–based parking systems. A new m-commerce parking system called the EZ M-parking system is proposed for both on-street and off-street parking. A unique number including a check digit is assigned to and painted on each parking space. Motorists need dial only a single number to start or end their parking service. Short message service (SMS) messages are used to send confirmations or reminders to motorists. Parking enforcement officers can check the occupancy of a parking space online or based on the SMS messages received from the management center. Officers can also send SMS messages to motorists if necessary. This system allows flexible pricing and accurate charging and includes several methods to reduce operation errors. The real-time parking occupancy data can help develop parking guidance systems and facilitate traffic and parking analysis. Motorists can buy prepaid parking cards similar to phone cards to deposit money into the account connected to their mobile phones. The EZ M-parking system is more cost-effective, user-friendly, and error-proof than conventional parking payment methods and other mobile phone–based parking systems.

PHS: Revolutionizing personal communication in Japan

Abstract This article presents an overview of the current state of PHS in Japan, focusing on differences between PHS and conventional mobile phones. The survey, conducted in December 1995, revealed that PHS users are younger, richer and more educated than conventional mobile phone users. Private use is more common than business use with PHS. PHS users show a great interest in advanced technologies, such as high-speed data transmission. The results suggest that PHS and conventional mobile phones may coexist in the future, targeting different types of customers.