Polarization-Diversity Conformal VHF Antenna with Near-Perfect Radiation Efficiency for Small UAVs

The integration of wide-band high efficiency antennas into conducting airframes especially at low frequencies is very difficult for two reasons: (1) Such antenna need to be large and cannot be protruding out of the airframe, (2) because most airframes are electrically conductive (aluminum or carbon fiber), conformal antenna printed on such surfaces have narrow bandwidth and low efficiency. A method is presented for realizing dipoles and monopoles with near-perfect efficiencies formed using airframe sections resulting in no additional RCS and requiring minimal wiring. Multiple realizations with varying polarizations are possible for small-size UAVs with conducting airframes.