Accession Number : AD0428242


Title :   JOINT ARMY-NAVY AIRCRAFT INSTRUMENTATION RESEARCH (JANAIR) ROTOR BLADE RADAR ANTENNA REPORT PHASE 1


Descriptive Note : Technical rept.


Corporate Author : BELL HELICOPTER TEXTRON INC FORT WORTH TX


Personal Author(s) : Lindenmeyer, Leonard R ; Young, David W


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/428242.pdf


Report Date : 13 Jan 1964


Pagination or Media Count : 98


Abstract : A research program to investigate the feasibility of using the main rotor blade of a helicopter as a radar antenna was conducted. Special blade sections were built and tested to study various design ideas. Digital computer studies of slotted arrays were programmed on an IBM 7070 computer at Bell. Both a 43-inch section and a 173-inch section of UH-1B rotor blade were built with a slotted array placed near the trailing edge. These blade antennas were statically tested. Radiation pattern measurements were made of beamwidths, sidelobe levels, and front-to-back ratios. The problem of transmitting energy to a spinning rotor blade was examined and preliminary sketches of the hub layout were made. A 0.28 degree beamwidth was obtained at the Rayleigh Range for the 173-inch blade with the antenna focused at infinity. Sidelobe levels and front- to-back ratio were 20 db. 054200


Descriptors :   *RADAR ANTENNAS , *ROTOR BLADES(ROTARY WINGS) , ANTENNA RADIATION PATTERNS , COMPUTER PROGRAMMING , DIGITAL COMPUTERS , DISTORTION , ERRORS , FEASIBILITY STUDIES , HELICOPTER ROTORS , K BAND , POLARIZATION , SLOT ANTENNAS , WAVEGUIDE COUPLERS , WAVEGUIDES


Subject Categories : Active & Passive Radar Detection & Equipment


Distribution Statement : APPROVED FOR PUBLIC RELEASE