Antenna device with direct differential input useable on an automated vehicle
An illustrative example transmission device, which is useful for an automated vehicle, includes a substrate having a metal layer near one surface of the substrate and a waveguide area. The metal layer includes a slot that at least partially overlaps the waveguide area. A source of radiation includes a first radiation output situated on a first side of the slot and a second radiation output situated on a second, opposite side of the slot.
1. A transmission device, comprising:
a substrate having a metal layer near one surface of the substrate and a waveguide area in the substrate, the metal layer including a slot that at least partially overlaps the waveguide area; and
a component mounted on the substrate with one side facing the metal layer, the component including a source of radiation, the source of radiation including a first source output on the one side of the component and a second source output on the one side of the component, the first source output being situated on a first side of the slot, the second source output being situated on a second, opposite side of the slot, each of the first and second source outputs outputting radiation from the source that establishes an electromagnetic field between the first and second source outputs such that the radiation from the source is coupled into the waveguide area through the slot.
2. The transmission device of claim 1 , wherein the radiation comprises differential radio frequency radiation, the first source output is a positive output of the differential radio frequency radiation, and the second source output is a negative output of the differential radio frequency radiation.
3. The transmission device of claim 1 , wherein the one side of the component overlaps at least a portion of the slot and the first and second source outputs are on opposites sides of the portion of the slot.
4. The transmission device of claim 3 , wherein
the component comprises a ball grid array at least partially on the one side of the component;
the first source output comprises a first ball of the ball grid array; and
the second source output comprises a second ball of the ball grid array.
5. The transmission device of claim 1 , wherein the slot is situated offset from a center of the waveguide area.
6. The transmission device of claim 1 , wherein
the radiation comprises radio frequency radiation; and
the radio frequency radiation radiates outward from the waveguide area of the substrate.
7. The transmission device of claim 1 , wherein the slot has a first portion oriented in a first direction and a second portion oriented in a second direction that is transverse to the first direction.
8. The transmission device of claim 7 , wherein the first direction is perpendicular to the second direction.
9. The transmission device of claim 1 , wherein the slot has a length that corresponds to one-half a wavelength of the radiation.
10. The transmission device of claim 1 , wherein the slot has a dimension that establishes a resonant frequency of the radiation in the waveguide area.
11. The transmission device of claim 1 , wherein
the metal layer defines an outer surface of one side of the substrate;
the metal layer has a thickness; and
the slot has a depth that is equal to the thickness.
12. The transmission device of claim 1 , comprising a solder mask between the metal layer and the one side of the component, the solder mask including a first source solder pad on the first side of the slot and a second source solder pad on the second side of the slot.
13. A method of making the transmission device of claim 1 , the method comprising:
establishing the slot in a metal layer on a first surface of the substrate at least partially overlapping the waveguide area of the substrate;
situating the first output of the source of radiation on the first side of the slot; and
situating the second output of the source of radiation on the second side of the slot.
14. The method of claim 13 , comprising situating the slot in a position that is offset from a center of the waveguide area.
15. The method of claim 13 , comprising providing the slot with a first portion oriented in a first direction and a second portion oriented in a second, different direction.
16. The method of claim 15 , wherein the first direction is perpendicular to the second direction.
17. The method of claim 13 , comprising providing the slot with a length that establishes a resonant frequency of radiation emitted by the waveguide area.
18. The method of claim 13 , comprising providing the slot with a length that corresponds to one-half a wavelength of the radiation.
19. The transmission device of claim 1 , wherein the radiation is directly coupled into the waveguide area from the first and second source outputs through the slot.
20. The transmission device of claim 1 , wherein the radiation is directly coupled into the waveguide area independent of any intermediate line connectors between the first and second source outputs and the slot.
21. The transmission device of claim 1 , wherein the first source output and the second source output are outside of the substrate.