Proposal of a TEM to TE01 mode converter for a microwave nondestructive inspection of axial flaws appearing on the inner surface of a pipe with an arbitrary diameter

2019 ◽  
Vol 59 (4) ◽  
pp. 1527-1534 ◽  
Author(s):  
Takuya Katagiri ◽  
Kota Sasaki ◽  
Haicheng Song ◽  
Noritaka Yusa ◽  
Hidetoshi Hashizume
2021 ◽  
Vol 92 (9) ◽  
pp. 094703
Author(s):  
Yong-jun Hu ◽  
Liang Xu ◽  
Qiang Zhang ◽  
Cheng-wei Yuan ◽  
Jin-liang Liu ◽  
...  

Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 103
Author(s):  
Tongbin Yang ◽  
Xiaotong Guan ◽  
Wenjie Fu ◽  
Dun Lu ◽  
Xuesong Yuan ◽  
...  

This paper proposes a taper cascaded over-mode circular waveguide TE0n mode converter for the millimeter and terahertz wave gyrotron. The mode converter of this structure can effectively reduce the difficulty of high frequency mode converter in fabrication. This paper verifies the feasibility of this new structure from theory, simulation, and experiment. Based on coupled wave theory calculations, three TE02-TE01 mode converters with lengths of 65.43 mm (4 segments), 119.3 mm (6 segments) and 136 mm (8 segments) and a TE03-TE02 mode converter with a length of 92 mm (8 segments) are optimized. The conversion efficiency in the frequency band 215–225 GHz is 91.8–94%, 93–95%, 95–98.78% and 95–98.44%. Because the length of the mode converter is clearly limited, this paper selects the TE02-TE01 mode converter with a length of 65.43 mm (4 segments) and the TE03-TE02 mode converter with 92 mm (8 segments) for simulation and experimental verification. In the simulation software Computer simulation technology (CST), the TE02-TE01 and TE03-TE02 mode converters and their composed TE03-TE01 mode converters are selected for modeling and analyzing. The simulation results and theoretical calculation results of the three mode converters only have different degrees of frequency deviation, and the frequency deviation of the 4-stage TE02-TE01 mode converter can be ignored; the frequency deviations of TE03-TE02 mode converter and TE03-TE01 mode converter are 2 GHz and 3 GHz, respectively. The experimental system is a field scanning system based on a vector network analyzer (VNA), which scans the input and output of the mode converter respectively. The experimental result is that when the input mode purity is 92% in TE01 mode, the output mode TE03 mode has a mode purity of 82%, and it has lower transmission loss. In this paper, the results from theory, simulation and experiment are in good agreement. This type of mode converter is easy to prepare, which makes it an effective alternative for high frequency curvilinear waveguide mode converter.


Author(s):  
Tinghui Peng ◽  
Yong Xu ◽  
Miao Sun ◽  
Ya Mao ◽  
Weijie Wang ◽  
...  

2015 ◽  
Vol 7 (3-4) ◽  
pp. 229-237 ◽  
Author(s):  
Christian Schulz ◽  
Christoph Baer ◽  
Thomas Musch ◽  
Ilona Rolfes ◽  
Bianca Will

A compact and broadband TE11-TE01-mode converter, suitable for various industrial applications like bypass level measurements, is presented in this contribution. Based on stepped waveguide technique, the main advantages of the recommended converter design and the specific field distribution of the TE01-mode are discussed in detail. The converter is presented exemplary for a frequency range from 23 to 28 GHz, which corresponds to a bandwidth of approximately 20 % of the center frequency. Numerous three-dimensional electromagnetic field simulations are performed to optimize the converter and to investigate its reflection and transmission behavior. Realized by six different single elements and 11 parts in total, fast and effective simulations can be performed with CST Microwave Studio. Considering realistic production process parameters, like fillets or tolerances, a good return loss better 17 dB, an insertion loss of 0.1 dB, and an excellent mode purity are achieved. Compared with back-to-back, realistic disturber scenario, and far-field measurements with a first prototype, the expected excellent converter behavior can be validated without limitations. Hence, the suitability of the presented converter design is proven and the feasibility is demonstrated.


2020 ◽  
Vol 64 (1-4) ◽  
pp. 465-472
Author(s):  
Takuya Katagiri ◽  
Guanren Chen ◽  
Noritaka Yusa ◽  
Hidetoshi Hashizume

In this study, a TE01 mode converter was developed to locate an axial crack on the inner surface of a metal pipe. Three-dimensional finite element simulation was conducted to evaluate the effect of inserted coaxial cables on the transmission characteristic of the mode converter. The result showed that the energy of TE mode microwaves leaned to transmit to one side when the cables penetrated with inclination. To demonstrate the effectiveness of the mode converter, experimental verification was conducted. The mode converter was fabricated based on the simulation result. Microwaves were emitted through the pipe wall of the converter to propagate on both sides (‘right side’ and ‘left side’) of a pipe with an artificial slit. Compared with the signals from each side, the reflection from the slit on the right side was more significant than that on the left side. This result is consistent with the numerical simulation result.


2011 ◽  
Vol 32 (11) ◽  
pp. 1307-1313 ◽  
Author(s):  
Yongshuai Wang ◽  
Zhongbin Cai ◽  
Xiaoke Kang ◽  
Yueling Liu

Sign in / Sign up

Export Citation Format

Share Document