Abstract: A broad bandwidth double balanced mixer with all circuitry contained on a single MMIC die is disclosed using planar magic tee hybrids to greatly reduce component quantity and die area. The hybrids comprise a Lange coupler followed by a capacitor and a quarter-wavelength transmission line on the direct path, in conjunction with a half-wavelength transmission line on the coupled path. The hybrid is essentially a planar realization of a magic tee, producing two equal magnitude outputs that are substantially 180 degrees separated in phase, with the coupled input terminated in 50 ohms. The mixer topology is a ring configured diode quad with two magic tee's at the RF and LO ports and a Wilkinson power divider at the IF port.

Abstract: A ring shaped dielectric resonator tuned by inserting a bolt from below the resonator into an opening of the resonator. The bolt causes the dielectric constant of the opening to change. The change in the dielectric constant changes the electric field which in turn changes the magnetic field of the resonator.