Study On IMT-advanced Base Station Antennas

Nowadays, the antenna can be seen anywhere. After all, the antenna is everywhere in our life.With the rapid development of wireless communication technology, all kinds of new technologyand new standards had continuously put forward, the requirements of the antenna were constantlyupdate, miniaturization, high power gain, wide band, and so on.Calculated data are presented on theperformance of printed antenna elements on substrates which may be electrically thick,as wouldbe the case for printed antenna at millimeter wave frequeneies. Printed dipole antennas areconsidered a lot.Based on the understanding of the antenna development form and the basic knowledge of theantenna, in order to adapt to the requirements of IMT-Advanced system development, aomnidirectional planar dipole array antenna is analyzed and successfully implemented in this paper.The elements used are one-sided printed dipole fed with a balanced twin-lead transmission line andserial-feeding method.Serial-feeding does not need to design feed separately,the space utilization isbetter. For interfacing the antenna to a50coaxial cable,a wide-band balun and a launcher systemfor the array were designed and implemented.Being associated with the research projects, this dissertation makes deeply insight to theprinted dipole antenna and the omnidirectional antenna with serial-feeding.To3.5GHz as anexample to design and introduce in this paper. The specific work are as follows:1. Research and design the serial-feeding method, using a transition between the connectorand the balanced transmission line to feed antannas.2. Introduced and analyzed the antenna which commonly used.And simple design aserial-feeding Microstrip Antenna with Omni-directional by electromagnetic simulationsoftware.3. A Omni-directional printed dipole antenna is designed and analyses its series array.Theantenna satisfied the requirements of the project through the debugging and the simulationof electromagnetic simulation software.4. Methods of detuning the bandwidth and reduce orientation image plane gained have beeninvestigated.And could see that it achieved good results by the results simulation.