The performance of VHF and UHF aerials mounted on carbon fiber composite materials

Antenna isolation, voltage standing wave ratio (VSWR) and radiation pattern measurements were compared for vhf and uhf antennas mounted on carbon fiber composite (CFC) and aluminum cylinders. There is little difference between the CFC and aluminum installations, although within the vhf aircraft communications band the results for the CFC cylinder indicate a greater VSWR and a less uniform azimuthal radiation pattern. One original panel section of a helicopter tail cone was replaced with CFC. Antenna isolation was measured between standard antennas on the helicopter and an antenna first mounted on the original panel and then on the replacement CFC and aluminum panels. No differences are found in the isolation results other than those caused by changes in the tail cone contour.