A.V. Vorobiev – Engineer, NIKA-Microwave, Ltd (Saratov)
B.M. Kats – Ph.D.(Eng.), Head of Department, NIKA-Microwave, Ltd (Saratov)
V.P. Meschanov – Honored Scientist of RF, Dr.Sc.(Eng.), Professor, Director of NIKA-Microwave, Ltd (Saratov)
K.A. Sayapin – Engineer, NIKA-Microwave, Ltd (Saratov)
Coaxial-waveguide transitions are widely used in the receiving-transmitting and measuring equipment of the microwave range. Among the variety of designs of coaxial-waveguide transitions, inductive type transitions in which the inner conductor of the coaxial connector is in galvanic contact with the waveguide are of interest. The advantage of this type of coaxial-waveguide transitions is that their coaxial connectors can be made without the use of solid dielectrics. This allows you to increase stability when operating the device at high power levels.
This paper proposes the design of coaxial coaxial-waveguide transitions of inductive type for rectangular waveguides of standard cross section and reduced height. The transition structure is formed by a resistance transformer based on a cascade connection of the single-ridged waveguide segments of various lengths and with different protrusion heights. The central conductor of the coaxial transmission line is galvanically connected to the first protrusion. Distinctive features of the proposed design of the transition are the presence of several matching cavities and different from the quarter-wave length of the segments of the single-ridged waveguide. Solved the problem of synthesis of coaxial-waveguide transitions for rectangular and flat waveguides of different cross sections. The features of the development of transitions for waveguides of reduced height are considered. A comparative analysis of a five-step transition of the proposed design and a four-step transition based on a synchronous type transformer for a waveguide of 57,17×29,08 mm was carried out. The return loss of the transition structure under study in the frequency range 3,2… 4,9 GHz is less than −34 dB, for a structure based on a synchronous transformer, no more than −30 dB in the range 3,3…3,9 GHz. The length of the modified transition is more than halved compared to the classical structure. Thus, the proposed topology of coaxial-waveguide transitions in comparison with the known analogues has advantages in frequency characteristics and overall dimensions.
- Meinke Kh., Gundlakh F.V. Radiotekhnicheskii spravochnik. T. 1. M.: Gos. energeticheskoe izd-vo. 1960. (in Russian)
- Feldshtein A.L., Yavich L.R., Smirnov V.P. Spravochnik po elementam volnovodnoi tekhniki. M.: Sov. radio. 1967. (in Russian)
- Cano J.L., Mediavilla A. Octave bandwidth in-line rectangular waveguide-to-coaxial transition using oversized mode conversion. Electronics Letters. 2017. V. 53. № 20. P. 1370−1371.
- Durga M., Tomar S., Singh S., Suthar L. Millimeter wave in-line coaxial-to-rectangular waveguide transition. IEEE Applied Electromagnetics Conference. 2011. P. 200-20.