Research Of Ultra-wide Band Balun Miniaturization

With the advancements of information technology, communication systemshave got a great development. The communication band have become increasinglydemanding, ultra-wideband deservedly become a very popular field of study.Ultra-wideband miniaturized antenna became popular in the hot. So far,ultra-wideband antennas are almost balanced antenna, thus it is necessary to useultra-wideband antenna feed balanced-unbalanced converter, also known as theBaron. As part of the antenna system, its miniaturization is also very important. Allthe above, the paper design the smaller Barron for two-arm and four-arm antennarespectively. Then introduce the idea of antenna miniaturization to achieve goodresults.Start of the research background of ultra-wideband antenna miniaturization andthe need for ultra-wideband balun miniaturization. Then show a simple analysis onthe development, characteristics and classification of ultra-wideband antenna.According to the impedance matching principle, design an index gradient Barron onthe basis of the the microstrip line of plane. Prove that its performance is better thana straight line gradient structure by simulation analysis. And join a spiral thinkingbased on the structure, design the the single spiral index gradient Barron tosubstitute the planar index gradient balun. In the case of satisfing the impedancematching, bandwidth is very wide; the overall size compared to the planar indexgradient Barron is also much smaller. But taking into account that a single spiralindex gradient Barron can only be used directly in the two arms ultra-widebandantenna feed, so put the two index gradient single-spiral balun together when thefour-armed ultra-wideband antenna feed was completed, then increase a group ofsingle spiral index gradient Barron, and make the two balance ports to be butt to buttrightly, rotate reversely to each other in the same plane,which similar to the rotationof the arms spiral antenna. The two single spiral index gradient Barron balance portupturned to connect the antenna, unbalanced ports respectively connected to thecoaxial line. This design can be directly fed balanced antenna of the four-armedpower, also to meet the design requirements of miniaturization.The design of miniaturized ultra-wideband balun can meet a much widerrequirements of bandwidth. Because the miniaturized Barron is an overall flatcylinder, it can be placed in parallel with the helical antenna. Connection of antenna is feasible to meet at the center of cylinder, so it engages a small footprint, can beused broadly in the future.