TWO-CONDUCTOR LOW-PASS TRANSMISSION LINE THEORY
Quarterly rept. no. 7
IIT RESEARCH INST CHICAGO IL
Pagination or Media Count:
A field analysis of a two-layer line was performed. It was show a TEM mode cannot propagate in such a structure. Instead, a TM mode will exist. Commercially fabricated low pass transmission lines were tested to determine how well the design specifications of these lines was met in a practical configuration. Two types of lines were fabricated. One used a conducting polyethelyne as the dielectric while the other utilized a conducting rubber compound for the same purpose. Due to contact problems between the two conductors and the dielectric material, neither of the lines met the design specifications. However, the shape of the attenuation versus frequency curve was as would be expected for a line with a shunt conductance lower than was the actual case. Improvement in the outer conductor contact enabled the response curve to be shifted down in frequency so that it more nearly approached the theoretical response. Several ferrite lines were also constructed and tested. These lines had an attenuation which varied in proportion to the square root of frequency.
- Electricity and Magnetism