VERIFICATION OF FEASIBILITY STUDY OF COUPLED LEAKY WAVEGUIDE SYSTEM FOR COMMUNICATION IN HIGH SPEED GROUND TRANSPORTATION
Laboratory-scale tests and extensive studies were carried out to verify the feasibility of a coupled leaky waveguide system. Aluminum waveguides with radiation holes and some components were fabricated for the test. The attenuation constants and coupling properties were measured, and these measurements agreed well with the theory. Installation of waveguides in a duct with plastic cover proved effective to eliminate foreign substances depositing thereon affecting transmission loss. Suppression of radiation was measured by use of various combinations of wall materials. Expected suppression radiation effects were obtained even with combinations of metal and concrete. The effect of rain on the attenuation and coupling were measured. Though phase distortion due to waveguide irregularity could not be measured, the theoretical limitation of phase distortion was obtained, which provided the data required to evaluate the waveguide properties employing the various modulation and multiplex systems and also the channel band width capacities. Signal-to-noise ratios were calculated for voice channels in typical cases of the coupled leaky waveguide system with a 400 mile waveguide length with estimates for FDM-FM and PCM-PM systems including the thermal, intermodulation, and distortion noises.
- See also PB-180 750.
Sumitomo Electric Industries LimitedTokyo, Japan
- Nakahara, T
- YOSHIDA, K
- Kuroda, M
- Kurauchi, N
- Takemura, K
- Publication Date: 1970-1-2
- Pagination: 141 p.
- TRT Terms: Communications; Intelligent transportation systems; Technology; Waveguides
- Geographic Terms: Japan
- Old TRIS Terms: Advanced systems
- Subject Areas: Operations and Traffic Management; Railroads;
- Accession Number: 00039169
- Record Type: Publication
- Source Agency: National Technical Information Service
- Report/Paper Numbers: Final Rpt
- Contract Numbers: DOT-FR-9-0042
- Files: TRIS
- Created Date: Nov 24 1973 12:00AM