Optimization And Research Of The Open-Ended Rectangular Waveguide Probe Of L、S、X Band

Open-ended rectangular waveguide probe (OEWG) is widely used in near-field scanning measurement, etc. As one of the core parts for measurement, its performance plays a pivotal role in the measuring accuracy of the whole system. Some foreign institutions have abilities to calibrate OEWG below Ka-band with high precision, compared with which China is short of this for a variety of reasons. Research topic of this paper, which belongs to the researching project of NIM EMC laboratory, aims to improve the calibration system of OEWG gain and pattern in L, S, X band to fill the domestic relevant field by optimizing the properties of OEWGThis paper represented by x-band, the author analyzed properties of the probe through CST simulation soft and summarized that OEWG have a larger return loss, a serious aperture diffraction and a weak radiation field strength and is easily affected by surrounding environment combined with some of the problems in practical use. These defects will reduce the precision of probe in probe calibration or application. To improve these problems, this paper first compared the two common modes of dielectric loaded, fully loading and dielectric loaded in the center of E face, which are found not very perfect. So introducing a new method of tapered dielectric loaded. We prove that the new method of tapered dielectric loaded effectively reduced5dB of the return loss, suppressed the backward current, improved the surface reflection, enhanced the gain about3dB and reduced surface current and HPBW combined simulation with measurement. The purpose to optimize the probe is basically achieved. Finally the author present the gain uncertainty of tapered dielectric loaded OEWG, which is only0.06dB.Utilizing the research results, tapered dielectric loaded OEWG probe can serve as a set of standard units with high precision gain in L, S, X band to assure the near-field scanning measurement, achieve high precision measurement of OEWG gain calibration, solve problems of OEWG absolute gain and pattern calibration and quantity traceability in the frequency range.