Radiation from Circumferential Slots on Plasma-Clad Cones

摘要

The radiation pattern distortion produced by a high-altitude, boundary-layer plasma is investigated for both symmetically and asymmetrically excited circumferential slot antennas on models of conical reentry vehicles that use an electric discharge simulation of the sheath. The slot configurations are selected to conform to nose-mounted telemetry antennas in current use, and the peak electron densities and electron density profiles are selected to approximate high-altitude reentry conditions. Measured patterns and theoretical predictions are compared for both bare and plasma-clad cones. These indicate large modifications of the radiation pattern in the forward direction, even for relatively thin and underdense plasmas. (Author)