Disclosed is a millimeter wave integrated circuit balanced mixer including wo signal ports, a local oscillator and an input signal port, coupled to a pair of solid state millimeter wave mixer diodes by means of an image guide 3db hybrid signal coupler and a pair of mixer cavities formed from a wafer of boron nitride whose bottom surface is metallized and soldered onto a metal substrate having a metal surface defining an image plane. The signal coupler consists of two curved lengths of boron nitride image guide having a spacing therebetween in the form of a thin slot for providing the proper coupling factor. The cavities formed in the boron nitride wafer are metallized and are configured to receive one like end of the respective image waveguides. The opposite ends of the image waveguides are tapered and are located in image guide to wavelength transitions at the respective signal ports. IF output signal lines in the form of metallized lines are located on the end portion of the image guides in the respective cavities for coupling to an IF amplifier.
The invention provides a coupling device between a metal wave guide (three dimensional system) and an electronic signal processing circuit (two dimensional system). The transition is provided by means of a dielectric wave guide introduced longitudinally into the metal wave guide. A chamfer cut in the dielectric guide concentrates the energy of the input signal on a face of the dielectric bar, at the interface with another dielectric material (isolated image guide). At this interface, a microstrip line transmits the energy to a semiconductor component.
A microwave converter comprises circuit components formed on the outer surfaces of a three-dimensional body. The inner surfaces of the body constitute a grounding surface. A local oscillator is disposed on one of the inner surfaces. The three-dimensional body may be an electrically conductive body having a hollow space in which the local oscillator is disposed.
A microwave/millimetric receiver of the kind in which a dielectric lens focusses incoming radiation on to an integrated antenna/mixer supported by a dielectric substrate. In one embodiment the antenna/mixer comprises a slot antenna and diode means coupled thereto for mixing the received signal with a local oscillator signal to form an IF signal. The local oscillator signal may be irradiated on to the antenna/mixer to be picked up by a crossed slot antenna or the local oscillator signal may be directly injected into the antenna/mixer circuit say via a microstrip line. In an alternative embodiment, the slot antenna is replaced by a dipole and a local oscillator signal is directly injected into the antenna/mixer via a coplanar line.
A dual Gunn self-oscillating mixer is shown which can mix signals in the range substantially without introducing any noise and with high input signal power handling capacity and with higher output mixed signal power than conventional, owing to boosted power from more than one microwave cavity. The device is comprised of two cavities and connected by a 180.degree. phase shift coax line for injection locking, or a cavity wall hole in yet another embodiment. The device handles larger power levels without burning out as compared to conventional type mixer devices such as Schottky barrier diodes having nearly 30 times the burnout susceptibility.
A triple Gunn diode self-oscillating mixer system is shown which can mix nals in the VHF range substantially without introducing any noise and with high input signal power handling capacity and with higher output mixed signal power than conventional, owing to boosted power from more than one microwave cavity. The device is comprised of three self-oscillating Gunn diode cavities connected by 180.degree. phase shift coax lines for injection locking. The device handles larger power levels without burnout as compared to conventional mixer devices such as Schottky barrier diodes having nearly 30 times less burnout capacity.
