AJ/LPI at millimeter wavelengths

The AJ/LPI advantages of millimeter wavelength communication at or near the 60-GHz oxygen line have been apparent to researchers for many years. Realizing the full extent of these advantages in a system appropriate for field operation requires more than simply designing a conventional communications link for operation at 60 GHz. Very low sidelobe, narrow beamwidth antennas of rugged construction and the use of frequency agility and spread spectrum modulation are also necessary. Construction of short range, clear weather tactical communication systems exploiting tropospheric oxygen absorption in the 50- to 70-GHz region appears feasible with current state-of-the-art solid-state components. The critical design parameters for achieving all weather jamming resistance and covertness are frequency selection, power management, waveform design, and antenna side- and back-lobe performance.