Accession Number : AD0855543

Title :   Aerodynamic Studies of Antenna Breakdown, Part I.

Descriptive Note : Final rept. 15 Jan 67-14 Jan 69,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE AEROPHYSICS LAB

Personal Author(s) : Covert, E. E. ; Haldeman, C. W. ; Boedeker, L. R. ; Sullivan, J.

Report Date : APR 1969

Pagination or Media Count : 101

Abstract : Work performed during 1967 and 1968 on the transmission and radiation characteristics of antennas on the surface of a plasma-covered wind tunnel model is reported. The model used is a blunted cone-cylinder operated in a supersonic wind tunnel at M = 4, P sub o = 1.2 psia and T sub o = 100F. The plasma sheath is obtained by injecting nitrogen plasma from a DC arc jet located in the model nose. The effect of the plasma on X-band and S-band antennas located on the model surface was studied and it was found that the breakdown power and transmitted power of an X-band slot were greatly reduced by the plasma layer. The presence of the plasma layer was also found to increase the VSWR of an S-band slot from 1.2 to 20. Some development efforts associated with improvement of the arc jet are also presented. (Author)

Descriptors :   *PLASMA SHEATHS), (*REENTRY VEHICLES, BLACKOUT(PROPAGATION)), (*ANTENNAS, ATTENUATION, ELECTRICAL IMPEDANCE, X BAND, S BAND, CONICAL ANTENNAS, MODEL TESTS, SLOT ANTENNAS, STANDING WAVE RATIOS, ELECTRIC DISCHARGES.

Subject Categories : Electrical and Electronic Equipment
      Radiofrequency Wave Propagation
      Unmanned Spacecraft

Distribution Statement : APPROVED FOR PUBLIC RELEASE