Miniature millimeter wave covert communications system

A miniature covert communication system was constructed for applications such as down-the-hill-radio and cable replacement, command-post communication, and ship-to-ship communication. The system operates at millimeter-wave frequencies using microstrip transmitters and receivers and uses four hybrid-microcircuit modules to provide the necessary signal encoding and decoding functions. Details of the construction of the units and of the laboratory and field tests performed with the units over a wide range of temperature and atmospheric conditions are reported