| With the development of ultra-wideband technology, various types of antennas with ultra wideband characteristics are also booming emerging, but several with ultra-wideband technology antenna of early use, such as biconical antenna, dipole antenna, slot ultra-wideband antennas, etc. inevitably there is too large, narrow bandwidth, poor time-domain performance of various defects, and the development of the micro-strip antenna to some extent make up for these shortcomings, The Vivaldi antenna as the more prominent features of such class, Several times frequency bandwidth or up to several tens of GHz bandwidth is such an antenna to a researcher left the deepest impression, while the moderate gain, good phase center stability is the reason it is widely used, but as a Vivaldi antenna a non-cycle end-fire antenna in the time domain also has a good performance, narrow pulse response distortion is very small, which is graded as an antenna, but it is better than a feature similar to such antenna. And have been developed out of (1) the traditional Vivaldi antenna (Vivaldi Antenna), (2) Antipodal Vivaldi antenna (Antipodal Vivaldi Antenna, AVA), (3) Balanced Antipodal Vivaldi antenna (Balanced Antipodal Vivaldi Antenna, BAVA), three antenna types stage of development.Based on previous studies, for BAVA antenna continuous improvement to achieve better performance.1 First, the microstrip line-slot line, with a line-sided slot line, microstrip line-parallel line, with a line-three parallel lines, SIW (Substrate Integrated Waveguide) and other ultra-wideband characteristics feed power balun simulation design, analysis of the main parameters affecting feeding balun ultra-wideband performance optimization to achieve better internal broadband impedance matching performance, analysis and comparison of the advantages and disadvantages of each balun reasons.2 Second, effect of various parameters is then on antenna performance and initial antenna design, the voltage standing wave ratio in a frequency band within 1.45-19GHz kept at 2 or less, and its compact antenna structure, so as to satisfy the indicator in the2-18GHz band then its miniaturization and physical processing, testing and validation.3 consider the high dielectric constant medium guiding influence on the antenna gain and the S-parameters, and compare the differences between the laws of different shapes directed antenna gain caused by experimental verification in different sizes, the last radiation of different dielectric constants on the influence of the external low frequency gain antenna to make summary, while the Corrugated Edges (Corrugated Edges, CE) cycle load technology to improve the low frequency antenna impedance matching makes the cutoff frequency to low frequency extension 0.3GHz and increasing influence of antenna gain. |
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