Cavity backed antenna with in-cavity resonators
AssigneeVayyar Imaging Ltd.
InventorsNaftali Chayat, Doron Cohen
Life of this patent
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Abstract
A compact wideband RF antenna for incorporating into a planar substrate, such as a PCB, having at least one cavity with a radiating slot, and at least one transmission line resonator disposed within a cavity and coupled thereto. Additional embodiments provide stacked slot-coupled cavities and multiple coupled transmission-line resonators placed within a cavity. Applications to ultra-wideband systems and to millimeter-wave systems, as well as to dual and circular polarization antennas are disclosed. Further applications include configurations for an antenna based on a monopole element and having a radiation pattern that is approximately isotropic.
Claims22
A radio-frequency (RF) antenna for a planar substrate, the antenna comprising:
- a plurality of electrically-conductive layers within the planar substrate;
- a lower cavity within the planar substrate, the lower cavity bounded by a bottom ground plane, by vertical sidewalls formed of electrically-interconnected portions of the electrically-conductive layers, and by a middle ground plane;
- an upper cavity recess within the planar substrate, the upper cavity recess bounded by the middle ground plane and by vertical sidewalls formed of electrically-interconnected portions of the electrically-conductive layers;
- wherein the middle ground plane has a slot which electromagnetically couples the lower cavity to the upper cavity recess;
- a monopole element electrically-connected at a lower end to the lower ground plane and extending into the upper cavity recess;
- wherein the monopole element is electrically-connected to a conducting strip within the lower cavity to form a lower resonator;
- and
- wherein the monopole element is electrically-connected at an upper end to a conducting pad within the upper cavity recess to form an upper resonator for radiating and receiving RF signals;
- and
- an input coupling in the lower cavity, for electromagnetically coupling the lower resonator to RF circuitry.
A radio-frequency (RF) antenna for a planar substrate, the antenna comprising:
- a dielectric material within the planar substrate;
- a plurality of electrically-conductive layers within the planar substrate;
- a recess in an upper surface of the planar substrate;
- a cavity within the planar substrate below the recess, the cavity containing a portion of the dielectric material and bounded by portions of the electrically-conductive layers and by vertical sidewalls formed of electrically-interconnected portions of the electrically-conductive layers;
- an antenna feed, for electromagnetically coupling the antenna to RF circuitry;
- a first resonator for radiating and receiving RF signals for electromagnetically coupling the antenna to an external RF field, the resonator including a monopole element in the cavity;
- and
- a second resonator including a horizontal transmission line in the cavity;
- wherein:
- the monopole element is electrically-connected at a lower end to a ground plane of the cavity and extending into the recess;
- the monopole element is electrically-connected at an upper end to a conducting pad within the recess;
- at least one of the horizontal transmission line resonators is electromagnetically coupled to the antenna feed;
- and
- at least one of the transmission line resonators is electromagnetically coupled to the monopole element.
Dependencies are inferred from the claim text.