A Compact Triple-band PIFA By Using Defected Ground Structure

In recent years, with the rapid development of mobile communication technology andthe high integration of integrated circuits, it strongly promotes the development of moderncommunications antenna to the miniaturization, broadband, multi-band, and built-inintelligent direction, while at the same time it put forward higher requirements for the planarinverted F antenna, as the mobile device terminal. Therefore, the design of miniaturization,broadband and multi-frequency of the microstrip antenna has become one of the importantsubjects of the current antenna research.Microstrip antenna has become the best choice of built-in antenna, with its unique lowprofile, conformal, small size, light weight. But at the same time, the disadvantage of its ownnarrow bandwidth and low gain, restrict its application to a certain extent. Microwavephotonic crystals as a new type of artificial electromagnetic materials with unique properties(Frequency Band Gap), has been widely used in microwave circuits, antenna design, and hasmade a lot of exciting research. The design of antennas using photonic crystal structural cansignificantly improve the indicators of the antenna, and even develop the new antenna designideas.At the first, this paper introduces the basic theory of the microstrip antenna (such as thebasic structure, the radiation theory, classification, motivation methods and relatedparameters), and then the paper introduces the small, broadband and multi-frequencytechnology of the microstrip antenna.The paper focuses on the use of defect characteristics of EBG to construct planarinverted F antenna, this method is different from the traditional methods. Defected groundstructure in the ground plane of the microstrip transmission line artificially etched single or asmall number of cell structure. Using the artificial defect patterns etched on the ground plane,it undermines the integrity of the EBG, introduce the defect mode in the band gap, so theelectromagnetic wave can be spread in the corresponding frequency band. A large number oftheoretical and experimental studies have proved this feature, and this feature is applied to thedesign of planar inverted F antenna. This paper designes a new type of triple-band planarinverted F antenna. The antenna creates a simple, compact structure to meet the requirementsof mobile terminals in the three bands of GSM900MHz/DCS1800MHz/UMTS2000MHz and achieves the multi-frequency, miniaturization and broadband of antenna.