Abstract: A microwave multiplexer has a set of independently tuneable signal channels coupled to a common waveguide. Each of the channels has input and output 3 dB couplers which are joined by cylindrical radiators carrying circularly polarized waves. Both TE and TM waves are propagated within a plurality of resonant cavities within each of the filters. Coupling between the cavities is provided by an array of slots and an array of probes wherein the slots couple TE waves and the probes couple TM waves. Adjustment of the slots and the probes provides for independent coupling coefficients for the two propagation modes. A set of coaxial line probe structures connect between the input and output couplers to end cavities of a filter for the launching of TM waves, there being discs in the end cavities adjacent the probes for converting energy of a TM wave to a TE wave, thereby providing both the TM and the TE wave propagation.

Abstract: A millimeter-wave, planar, balanced mixer having optical means for coupling radio frequency waves to the mixer circuit. The optical coupling means may comprise a dielectric lens and particularly a spherical dielectric lens. The spherical lens not only provides a gain for the radio frequency energy but overcomes the severe tolerance requirements and size restrictions encountered in fabrication of conventional waveguides for millimeter waves in the range of 100 to 300 GHz.