Study Of Mobile Communication Base Station Antennas

This paper mostly investigates dual-frequency base station antenna, electric tiled antenna, power divider and phone-shifter. Dual-frequency antenna is indispensable part to transient process from 2G to 3G. This antenna split into two bands, low frequency and high frequency. This antenna can replace the 2G antenna on the primary base station, then a lot of money can be saved on the new base stations built. Main beam tile can promote frequency multiplexing, mechanical tilt has low precision and troublesome. But electric tile has high precision and can be operated by computers. The electric tilt antenna is the direction in microcellular system.Dual-frequency element is the groundwork of the dual-frequency antenna, the right element can not only advance the electrical property index, but also offer the convenience to the array. The structure of the dual-frequency is this: the high frequency on top, the low frequency underneath, dual-patch adopted in the high frequency and the bandwidth be increased. The element size is very alright and the array can be designed easily. In array the space between the low frequency elements is twice of the low. This is very felicity, it keep the equate space between the elements for the two bands, it is prone to design of the array.There are several ways to realize the beam tilt, such as unequal scope, unequal phase and the mix of the two ways. But the beam tile certainly will result in the high side probe level. So debasing the side lobe level must be carried out before realizing the tilt. Debasing the side lobe have several ways, such as unequal scope, unequal interval, unequal phase and the mix of the three ways. For simply the design adopts equal interval antenna array, adopts unequal scope to debase the side lobe level, adopts unequal phase to realize tilt. Changing the scope has no influent in theory. Actually the influence is very little. These may be realized by power divider and phase shifter.Power divider is the indispensably part, this paper designs microstrip power divider, equational and not equational. Not equational power divider is mostly adopted to decrease the side lobe. Phase shifter is adopted to realize the beam...