| Microstrip antennas have gained great progress due to their merits such as low cost, low profile, ease of fabrication and integration convenience. In recent years, the band-notched UWB antenna and multi-band antenna are two popular research topics on microstrip antenna. Besides, challenges during these researches are the rigorous requiremens of designing antennas with smaller dimensions and better performance.The first chapter is the introduction of the thesis, mainly describing the background and the current situation of the research. The second chapter represents the theory foundation of the thesis, including the basic concepts of antennas, the basic theory of microstrip antenna, the fundamental theory of band-notched UWB antenna and multi-band antenna as well as the feeding theories of microstrip antenna. O n the basis of the theories presented in the second chapter, the most important work in this thesis of antenna designing is done in the third and fourth chapters, containing the antennas' structure, performance, optimizing procedure, and results of both simulation and measurement.Three antennas are introduced in the thesis including one UWB antenna with three bandes notched, one dual-band antenna and one CPW-fed triple-band antenna. The labour done by the author can be divided into three parts, detailed as following:1. The three bandes notched UWB antenna is fabricated on a FR4 substrate with a continuous goblet-shaped patch on the upper side and a DGS ground on the other side, up to the ground a strip- loaded CSRR(complementary split ring resonator) is added to generate band- notch feature of the X-band satellite communication frequency range(7.25-7.75GHz). A pair of parallelled U-shaped meandering slots are designed on the ground to produce the band- notch feature of the C-band satellite communication frequency range(3.7-4.2GHz), of which the meandering slots design enable the long slots cut on the limited area of the ground.2. The dual-band antenna is composed by two FR4 substrates with the radiating patch designed on the upper side of the lower substrate and the ground on the lower side. A parasitic patch is designed on the lower side of the upper substrate for enhancing the antenna gain and broaden the working frequency bandes, beside, the parasitic upper substrate can also work as a protecter of the entire antenna.3. In this part, a triple-band antenna is designed with an overall size of 326.6 ?18?0.8mm. The antenna operates in Blue Teeth, C-band and 5GHz-WLAN band well. The antenna is very concise in structure and proved to be a well- functioned triple-band antenna through measurement. |
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