SYNTHESIS OF TRANSITION TWO-PORT FOR VHF TRANSMISSION LINES WITH CONDUCTING JUNCTION-ELEMENTS
Journal Title: Вісник Національного університету "Львівська політехніка", серія "Радіоелектроніка та телекомунікації" - Year 2015, Vol 818, Issue 2015
Abstract
The transition two-port (TT) for VHF transmission lines, as is known, transforms the wave type, frequently the TEM line wave mode into TE waveguide mode, and vice versa. In TT structure the most important is line junction-element (exciter) type (vibrator, coil, a. o.), and also reactance type for TT tuning. Thus it is possible to present the TT structure as the junction-three-port (JT), whose one port is by tuning reactance loaded. As an example in the paper is a TT with vibrator junction-element for coaxial line and rectangular waveguide considered. The tuning reactance here is a section of shorted waveguide. Main characteristic quantity for TT device is the wavelength-band width, and corresponding value of reflection coefficient. Usually for TT device the middle wavelength of band-width is given. At the designing of TT device it is necessary all efforts for wavelengthband widening to made. Such the optimization problem for geometrical sizes of TT structure elements arise. The proposed here TT synthesis algorithm is on results of junction-element (exciter) electrodynamics’ analysis based. These results are in analytical part of synthesis algorithm used. For that calculation the VHF circuit theory is applied. In high regret, the electrodynamics’ analysis results we get from none closed expressions in numerical form. Therefore we are forced the numerical synthesis to realize, for which geometrical sizes of junction-element structure must be given. In our case by electrodynamics’ analysis we get the value of input impedance and argument of transmission coefficient between coaxial line and waveguide JT ports. These numerical values serve for scattering matrix elements of JT calculations, use the equations for loss free structure. By aid of one contour signal flow graph reflection coefficient from TT input, and corresponding wave-band width is determined. The mentioned above numerical synthesis algorithm expects the zero value of reflection coefficient from TT input at the middle wavelength, and correspondingly narrow wavelengthband width. The line wave-resistance value can be for that calculation sufficient low accepted.42 For wavelength-band widening it is possible the optimization of arbitrary geometric size of TT structure to apply. Here for that purpose is choosing of coaxial line wave-resistance used. The enlargement of that resistance disturbs the TT structure. Then at the middle wavelength arise the reflection, and simultaneously appears greater wavelength-band width. It is to emphasize, that up today in technical literature the TT synthesis problem is not considered. Only the electrodynamics’ analysis of junction-element (exciter) is today into considerations taken. Thus we have the evidence, that the TT synthesis is by costly experimental methods realized. The presented numerical synthesis of TT structure provide the possibility for optimization, and cheaper the designing process of TT structure.
Authors and Affiliations
Yosyf Zahariia
Keywords
Related Articles
- EP ID EP458481
- DOI -
- Views 147
- Downloads 0
THE DISPERSION EQUATION FOR MODE SPECTRA EVALUATION IN OPENED LAYERED CYLINDRICAL DIELECTRIC WAVEGUIDES
This paper is devoted to the solving an eigenvalue problem for opened layered cylindrical waveguide structure with arbitrary finite number coaxial magnetodielectric layers. Classical method of separation of variables for...
RECTILLINEAR ARRAYS AND THEIR COMBINED RADIATION PATTERNS
A disadvantage of simple antenna is they do not always perform to specified requirements, such as the required width of the main lobe of radiation pattern (RP). In response, we often utilize straight array (SA) containin...
RELIABILITY MODEL OF FAULT-TOLERANT SYSTEM BASED ON THE MAJORITY STRUCTURE {3 OF 5} WITH COMBINED STRUCTURAL REDUNDANCY AND MAINTENANCE
Designing of radio-electronic systems of responsible purpose with hardware-software implementation involves the mandatory provision of their property of fault-tolerance. The property of fault-tolerance are provided by th...
SUBPIXEL IMAGE PROCESSING IN MONITORING SYSTEMS OF VISIBLE WAVELENGTHS
This paper is devoted to considering of ways to improve the resolution, principles and methods of subpixel imaging technology, assessment of the development status and the latest research developments. Modern approaches...
THE THEORETICAL ASPECTS AND PRACTICAL FEATURES MULTI-OBJECTIVE OPTIMIZATION OF PROCESSES TO ENSURE THE QUALITY OF REE AT THE MANUFACTURING STAGE
One of the most important scientific and technical problems is to ensure the quality and reliability of technical objects. In this paper the theoretical and practical aspects of modeling and optimization of quality assur...