Radio frequency coupling structure and a method of manufacturing thereof

Patent metadata

Field	Value
Publication number	US-9887449-B2
Application number	US-201414473038-A
Country	US
Kind code	B2
Filing date	Aug 29, 2014
Priority date	Aug 29, 2014
Publication date	Feb 6, 2018
Grant date	Feb 6, 2018

Abstract

A radio frequency transmission structure couples a RF signal between a first and a second radiating elements arranged at a first and a second sides of a first dielectric substrate, respectively. The RF coupling structure comprises: a hole arranged through the first dielectric substrate, a first electrically conductive layer arranged on a first wall of the hole to electrically connect a first and a second signal terminals, a second electrically conductive layer arranged on a second wall of the hole opposite to the first wall to electrically connect a first and a second reference terminals. The first electrically conductive layer is separated from the second electrically conductive layer. The hole extends beyond the first wall away from the second wall.

First claim

The invention claimed is:

1. A radio frequency coupling structure for coupling a radio frequency signal between a first radiating element arranged at a first side of a first dielectric substrate and a second radiating element arranged at a second side of the first dielectric substrate, the second side being opposite to the first side, the radio frequency coupling structure comprising:
a hole arranged through the first dielectric substrate extending from the first side to the second side, the hole having a non-elliptical shape in cross section, the hole including a first part, a second part, and a third part, wherein the first part includes a first wall and a second wall, the second wall being spaced apart from and facing the first wall, the second part of the hole intersects with the first part proximate a first end of the first wall, the third part of the hole intersects with the first part of the hole proximate a second end of the first wall such that the first and second parts are spaced apart from one another by the first wall, and the first and second parts extend in a lateral direction beyond the first wall and away from the second wall;
a first electrically conductive layer arranged on the first wall of the hole for electrically connecting a first signal terminal of the first radiating element to a second signal terminal of the second radiating element;
a second electrically conductive layer arranged on the second wall of the hole for electrically connecting a first reference terminal of the first radiating element to a second reference terminal of the second radiating element,
the first electrically conductive layer being separated from the second electrically conductive layer in the first part of the hole.

2. A radio frequency coupling structure as claimed in claim 1 , wherein:
the second part of the hole includes a first sidewall having a first edge that intersects with the first end of the first wall; and
the third part of the hole includes a second sidewall having a second edge that intersects with the second end of the first wall, the first and second sidewalls extending away from the first and second walls of the first part of the hole.

3. A radio frequency coupling structure as claimed in claim 2 , the first electrically conductive layer extending from the first edge to the second edge.

4. A radio frequency coupling structure as claimed in claim 3 , the first electrically conductive layer having a first width extending from the first edge to the second edge, the second electrically conductive layer having a second width aligned with the first width that is larger than the first width.

5. A radio frequency coupling structure as claimed in claim 1 , wherein the first part of the hole has a third sidewall and a fourth sidewall facing the third sidewall, the third and fourth sidewalls being spaced apart from one another by the second wall of the first part of the hole, and the second electrically conductive layer extends from the second wall onto each of the third and fourth sidewalls of the first part of the hole.

6. A radio frequency coupling structure as claimed in claim 1 , wherein the second and third parts of the hole extend laterally beyond the first wall of the first part of the hole by at least two microns.

7. A radio frequency coupling structure as claimed in claim 1 , the first dielectric substrate having a first dielectric constant, the hole being filled with a dielectric material having a second dielectric constant substantially smaller than the first dielectric constant.

8. A printed circuit board comprising the radio frequency coupling structure according to claim 1 , the printed circuit board comprising:
a first board electrically conductive layer,
a first board dielectric substrate,
a second board electrically conductive layer,
the first board electrically conductive layer being arranged on the first board dielectric substrate, the first board dielectric substrate being arranged on the second board electrically conductive layer,
the first board dielectric substrate comprising the first dielectric substrate,
the first board electrically conductive layer comprising the first signal terminal and the first reference terminal of the first radiating element,
the second board electrically conductive layer comprising the second signal terminal and the second reference terminal of the second radiating element.

9. A printed circuit board as claimed in claim 8 , wherein the first radiating element is formed in an integrated circuit package coupled to the first board electrically conductive layer and is electrically coupled with the first signal terminal and the first reference terminal and/or the second radiating element is formed in a separate electrically conductive layer vertically displaced from the second board electrically conductive layer and is electrically coupled with the second signal terminal and the second reference terminal.

10. A printed circuit board as claimed in claim 8 , further comprising:
a third board electrically conductive layer,
a second board dielectric substrate, and
a fourth board electrically conductive layer,
the second board electrically conductive layer being arranged on the third board electrically conductive layer, the third board electrically conductive layer being arranged on the second board dielectric substrate, the second board dielectric substrate being arranged on the fourth board electrically conductive layer,
the second radiating element being partially formed on the fourth board electrically conductive layer, wherein the second signal terminal of the second board electrically conductive layer is in electrical contact with the second radiating element by way of an electrically conductive via hole extending through the second board dielectric substrate.

11. A printed circuit board as claimed in claim 8 , the first radiating element and/or the second radiating element being one of the group comprising: a single-ended microstrip antenna, a differential microstrip antenna, a rectangular patched single-ended antenna, a rectangular patched differential antenna, a square patched single-ended antenna, a square patched differential antenna, a co-planar waveguide, a slotline.

12. A printed circuit board as claimed in claim 8 , the first reference terminal and/or the second reference terminal being electrically connected to a reference potential.

13. A radio frequency device comprising the radio frequency coupling structure as claimed in claim 1 , the radio frequency device further comprising:
an integrated circuit package arranged at the first side of the first dielectric substrate, the integrated circuit package comprising an integrated circuit die,
the integrated circuit die being electrically connected to the first radiating element and arranged for generating the radio frequency signal for transmission via the first radiating element and/or for receiving the radio frequency signal as received via the first radiating element.

14. A radio frequency device as claimed in claim 13 , the integrated circuit die comprising a circuit of the group of circuits consisting of: a transmitter, a receiver, and a transceiver, the circuit being electrically coupled to the first radiating element.

15. A radar sensor for detecting targets in a field of view comprising the printed circuit board according to claim 7 , the radar sensor further comprising:
an antenna electrically coupled to the second radiating element for transmitting and/or receiving the radio frequency signal through a frequency channel.

16. A method of manufacturing a radio frequ

Assignees

• Qiang Li
• Hartin Olin Lee
• Reuter Ralf
• Tong Ziqiang
• Nxp Usa Inc

Inventors

• Qiang Li
• Hartin Olin Lee
• Reuter Ralf
• Tong Ziqiang

Classifications

• H01P5/024 Primary

  between hollow waveguides · CPC title

• H01P3/121

  integrated in a substrate · CPC title

• H05K2201/09981

  Metallised walls · CPC title

• G01S7/03

  Details of HF subsystems specially adapted therefor, e.g. common to transmitter and receiver · CPC title

• H05K1/144

  Stacked arrangements of planar printed circuit boards · CPC title