The antenna of a mobile phone, which is a terminal equipment for transmitting and receiving electromagnetic waves, plays a vital role in mobile communication. A dramatic growth has been seen the mobile industry; it has evolved from analog to digital second generation (2G) GSM communication, then to high data rate third generation (3G) wideband code division multiple access (WCDMA), further to packet-optimized 3.5G High Speed Packet Access (HSPA) and fourth generation (4G) (Long Term Evolution (LTE) and LTE Advanced) systems and now moving towards fifth generation (5G) wireless communication system. As the smartphone era unfolds, the operating frequency band of the mobile phone is becoming wider and the space for a smartphone antenna is limited. It is very significant to design a compact wideband antenna for mobile phone application with a limited space. In recent years, the printed antenna has been widely adapted in wireless devices be- cause it can be printed directly on the PCB along with other circuitry at a low cost.
In mobile communication, the common 2G, 3G, and 4G bands are GSM850 (824– 894 MHz), GSM900 (890–960 MHz), GSM1800 (1,710–1,880 MHz), GSM1900 (1,850–1,990 MHz), UMTS2100 (1,920–2,170 MHz), LTE2300 (2,305–2,400 MHz), and LTE2500 (2,500–2,690 MHz). The realization of the compact multiband antenna through excellent design and proper impedance matching is the main design objective of cell phone antennas. In recent years, to meet the requirements of current mobile phone built-in antennas, monopole antenna, PIFA antenna, and many other types of antennas have been designed. A navigation antenna is specially provided in most phones, which mainly covers the GPS band.
Chapter-3 of the book “Practical Microstrip and Printed Antenna Design” is dedicated to Mobile Phone Antenna Design.