COMPACT H-F AIRCRAFT ANTENNAS (2-30 MHZ)
Abstract
The program effort reported here is primarily concerned with the design and development of a broadband, compact, omnidirectional airborne antenna in the H-F communications range (2 to 30 MHz) to be used on several U.S. Army aircraft, both fixed and rotary wing. Additional investigations are presented on a low profile wire antenna located on the aircraft tail at close proximity to the aircraft skin. The various exploratory element configurations reported here are loop-type structures intended to induce currents on the airframe for a predominantly vertical polarized system. The final model H-F antenna delivered as the result of this program is a two-turn grounded loop. Scaled models of two aircraft, one rotary and one fixed wing, were built for pattern, impedance, and gain measurements. Data are presented illustrating the effect of the antenna configuration, orientation, and location on the particular scale model aircraft. Manual L-C tuners were built for the 1/5-scale antennas to facilitate impedance matching for the relative gain comparison measurements. The application of ferrite to the H-F antenna has been considered. Measured field strength of a matched transmitting coil, with and without ferrite material, is presented. A full-scale breadboard model of the two-turn loop was successfully tested with a Univac automatic tuner for high power and impedance tuning. Environmental tests were performed on the full-scale final model antenna. The antenna was subjected to various vibration levels which resulted in structural modifications to the delivered model antennas. The Design Plan, Test Plan, and Environmental Test Results are included.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1967
- Accession Number
- AD0820118
Entities
People
- J. H. Hendershot
Organizations
- Glenn L. Martin Company