Application And Optimization Of Ultra Wideband Antenna In Time Domain Near Field Measurement

Along with the advance of science and technology, radar and communication technology is developing rapidly to the trend of broadband, in this situation, a higher requirements are put forward to the corresponding antenna measurement technology. Time-domain near-field antenna measurement can receive the performance of the antenna in the spectrum of the test required by a near-field scanning test, which can effectively reduce the construction cost of the testing system by high efficiency and low price of the measuring instrument. As an important part of the time domain near field measurement system, the structure and characteristics of the probe can also play a key role in the accuracy of the test results. In order to improve the accuracy of the results from near field measurement, A wide bandwidth, low profile, the far field radiation pattern with low cross polarization, nearly omnidirectional half space covered, low after the disc level, pure polarization and stable directional diagram, etc are put forward to the probe.Combined with practical work, this paper mainly studied if print gap monopole antenna and linear gradient slot antenna can be used on the time domain near field measurement system probe antenna. The two kinds of slot antenna have advantages of simple structure, low profile, small size and easy processing, etc. First of all, the paper discovered the feasibility of print gap monopole antenna as a time domain near field measurement probe through the improving of print gap monopole antenna’s gap structure and feed structure. Through simulation analysis, the impedance bandwidth of the antenna is 3.08-11.18GHz. When the frequency range is not large, the antenna radiation pattern is basically stable, and the antenna is covered in half space.Secondly, through the analysis of the linear gradient slot antenna parameters, and uses the way to increase the reflection board, the paper explored the feasibility of it as a probe antenna. Through simulation, it is found that the antenna in 0-10.3GHz the frequency range of and the reflection coefficient S11 is less than-10dB, stable radiation diagram, radiation is small, approximately the same as in the half space gain and half space coverage close to the omnidirectional antenna.Through the above work, two types of antenna probes are obtained. This two types of slot antenna radiation pattern is stable, can be used for a wide range of bandwidth, in half space coverage close to omnidirectional, able to achieve the target requirements, is very suitable for use as a probe antenna.