The Design And Measurement Of Multi-Band Mobile Phone Antenna

With the drive of continuous upgrade and improvement of our mobile communication industry, the mobile communication has entered 4G era. With the popularity of 4G communication, the cell phone is given more functions to adapt to new demands. As an important front component of cell phone, the mobile phone antenna needs to expand the bandwidth continuously to cover more frequency bands. The Antenna with one band can't satisfy the requirement of modern mobile phone antenna, since the research on multi-band antenna has a very important practical significance. Meanwhile, miniaturization is the goal of antenna design all the time, because the size reserved for the mobile phone antenna is limited, sometimes even irregular. And the research on multi-frequency is also an important subject in the field of mobile phone antenna. In general, the researches on mobile phone antenna mainly focus on miniaturization, multi-frequency and broadband. The multi-band mobile phone antenna is the main point of this thesis, meanwhile, the miniaturization is also considered.Firstly the thesis briefly summarizes the basic theory of cell phone antenna, including external antenna and internal antenna, the design of matching circuit and the methods on miniature, multi-frequency and broadband mobile phone antenna. Then two common types of built-in antenna: Planar Inverted F Antenna(PIFA) and Monopole Antenna, are selected to implement multi-band design, both forms can look on as one type of microstrip antenna. With the help of simulation software, two types of multi-band PIFA designed within the limited space can work in the bands of GSM850/GSM900/PCS/WLAN and GSM900/PCS/LTE2300 respectively. Two types of monopole antenna within the limited space both work in the bands of GSM900/DCS/PCS/UMTS/WLAN/LTE2300/LTE2500. Antennas designed in this thesis are simple in structure and the reflection coefficients are less than-6d B in required bands. The peak gains in each band are more than 0d B, the patterns basically meet omnidirection and the size of antennas is small. Antennas can meet the demands of antenna design and have good application value. In addition, the thesis also summarizes the basic theory of antenna measurement, including passive and active measurements, and describes the general composition structures of passive and active measurement systems. Other than common active parameters, from the point of health, SAR is increasing more attention, and HAC is also a technical index associated with the user's daily use, so both of them are introduced in this thesis briefly.At last, we summarize the thesis and put forward some improvement directions for the shortages appearing in the thesis.