Mixer, radar module, and communication apparatus incorporating the same

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION FIGS.
1A and 1B show the structure of a mixer according a first embodiment of the present invention.
FIG.
1A is a perspective view of the main part of the mixer when upper and lower conductive plates are removed.
FIG.
1B is a section of the main part thereof.
In these figures, reference numeral 4 denotes a rectangular planar dielectric substrate.
An electrode 5 is formed on the lower surface of the substrate 4 and electrodes 6a and 6b are formed on the upper surface thereof.
The electrode 5 and the electrodes 6a and 6b are arranged such that electrode apertures 9 and 10 are opposed to each other via the dielectric substrate 4.
The part of the dielectric substrate sandwiched between the mutually opposing electrode apertures 9 and 10 serves as a rectangular planar TE-mode dielectric resonator.
In addition, a slit 7 continuous with the electrode aperture 10 is formed on the upper surface of the dielectric substrate 4.
A mixer diode 15 such as a Schottky barrier diode is connected in a manner bridging the slit 7.
In each of FIGS.
1A and 1B, reference numeral 3 denotes a dielectric strip.
The dielectric strip 3 is arranged between conductive plates 1 and 2 shown in FIG.
1B to form a dielectric line (NRD guide) comprising the conductive plates 1 and 2 and the dielectric strip 3.
In addition, the electrode 5 is formed on the lower main surface of the dielectric substrate 4 and the electrodes 6a and 6b are formed on the upper main surface thereof.
A circuit board 13 includes the dielectric substrate 4 having these electrodes formed thereon and the diode 15 mounted thereon.
The circuit board 13 is arranged between the upper and lower conductive plates 1 and 2 making parallel conductive planes.
The rectangular planar TE-mode dielectric resonator composed of the electrode apertures 9 and 10 is arranged near an end face of the dielectric strip 3.
With this arrangement, the LSM01-mode electric and magnetic fields of the dielectric line propagating through the dielectric strip 3 are coupled with the rectangular planar TE-mode dielectric resonator