Coaxial Power Dissipation Line.
DEPARTMENT OF THE ARMY WASHINGTON DC
Pagination or Media Count:
This invention relates to VHF inverted-V antennas and, more particularly, to a termination for a half-rhombic directional antenna used for ground-to-ground communications. As is known and understood, inverted-V half-rhombic antennas have been considered for use in ground-to-ground communications systems because of their tactical directional antenna capability in the VHF range. In usage where a five port multicoupler is employed in conjunction with five radio equipments, each operating at a different frequency, as much as 200-400 watts of RF power is fed into the antenna input. Under such conditions, approximately half the power has to be dissipated in the antenna termination -- and, typically, noninductive, lumped resistors have been employed. The termination of the present invention includes a transformer terminated into a length of high attenuation coaxial transmission line cable acting as a power dissipation line. The termination transformer is selected to step-down the characteristic impedance of the inverted-V antenna to match the termination coaxial cable impedance, and the coaxial cable operated open-ended in a length required to obtain sufficient attenuation and to dissipate the heat generated.
- Electrical and Electronic Equipment
- Radio Communications