Metallized Dielectric Horn and Waveguide Structures for Millimeter-Wave Oscillator/Mixer Systems

A new method of producing millimeter-wave oscillator/mixers and associated antenna horns has been developed. This uses the technique of metal coating of dielectric body, and hence avoids the expensive and difficult machining of conventional metal cavities. A sensitive self-oscillating mixer has been tested in this structure and shown to be free from the unstable operation associated with surface radiation of unshielded dielectric waveguide. Low epsilon_r dielectric was used, thus facilitating ease of matching in contrast with the high epsilon_r necessary with the unshielded guide.