Tightly-coupled PCB GNSS circuit and manufacturing method

• US 7,948,769 B2
• Filed: 09/26/2008
• Issued: 05/24/2011
• Est. Priority Date: 09/27/2007
• Status: Active Grant

• Current Assignee: Hemisphere GNSS(USA) Incorporated
• Original Assignee: Hemisphere GPS LLC (Kubota Corporation)
• Inventors: Jakab, Andrew J., Boorman, Nicholas J.
• Primary Examiner(s): Takaoka; Dean O
• Application Number:
  US12/239,312
• Publication Number:
  US 20090085815A1
• Time in Patent Office: 970 Days
• Field of Search: 333/24.R, 361/679.01, 361/748, 361/760, 361/767, 361/782, 361/784, 361/792, 455/272
• US Class Current: 361/799
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 1/52 Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure absorbing means H01Q17/00
• CPC Class Codes: H05K 1/023 using auxiliary mounted passive components or auxiliary substances printed passive components H05K1/16
• CPC Class Codes: H05K 1/0231 Capacitors or dielectric substances
• CPC Class Codes: H05K 1/0237 High frequency adaptations H05K1/0216 takes precedence
• CPC Class Codes: H05K 2201/09972 Partitioned, e.g. portions of a PCB dedicated to different functions; Boundary lines therefore; Portions of a PCB being processed separately or differently
• CPC Class Codes: Y10T 29/49018 with other electrical component

Abstract

A tightly-coupled printed circuit board (PCB) circuit includes components mounted on a PCB enabling smaller integrations using decoupled lines extending between reference layers, such as ground planes, form isolation islands on the PCB. The decouplers are capacitors, inductors and/or resistors in tandem with ground layers of the PCB. The isolated components can comprise high-frequency RF antennas and receivers, for example in a GNSS antenna-receiver circuit. Multiple antennas can be connected to one for more receivers with multiple, independent RF front end components by RF traces, which are either embedded within the PCB between the ground planes, or by surface microstrip antenna traces.

Claims

1. A method of tightly coupling a printed circuit board (PCB), which method comprises the steps of:

providing a PCB with multiple conductive layers;

separating said conductive layers with insulating layers;

providing a positive reference layer;

providing a ground plane comprising a grounded reference layer;

providing a signal layer;

photoetching the signal layer to define a circuit;

providing electrical components;

connecting each electrical component to one or more layers;

forming a decoupling line in said PCB; and

forming an electrical isolation island in said PCB with said decoupling line.

2. The method of claim 1 wherein one of said components comprises a receiver, which method includes the additional steps of:

providing said PCB with a perimeter;

connecting said receiver to said PCB; and

extending said decoupling line from said receiver to PCB perimeter.

3. The method of claim 2 wherein said components include an antenna, which method includes the additional steps of:

providing an RF transmission line connecting said antenna to said receiver; and

locating said antenna in said isolation island.

4. The method of claim 3, which includes the additional steps of:

forming an optimal RF path from the antenna to the receiver, thereby creating a decoupling line; and

forming said isolation island along said decoupling line path.

5. The method of claim 2, which includes the additional steps of:

locating said receiver in an interior area of said PCB;

providing a pair of said decoupling lines; and

extending said decoupling lines from said receiver to said PCB perimeter.

6. The method of claim 1, which includes the additional step of:

forming said decoupling line with a plurality of discrete decouplers each extending through said PCB layers.

7. The method of claim 3, which includes the additional steps of:

providing said PCB with three sections each terminating at an outer end;

locating said receiver centrally with said PCB sections extending outwardly therefrom;

mounting an antenna in each of said sections in proximity to its outer end;

extending a pair of said decoupling lines from said receiver to each said PCB section outer end; and

forming an isolation island in each said PCB section with said antenna located therein.

8. A method of manufacturing a tightly-coupled PCB circuit with a power supply, a GNSS receiver and first and second GNSS antennas, which method comprises the steps of:

providing a PCB with multiple conductive layers;

separating said conductive layers with insulating layers;

providing a positive reference layer;

providing a ground plane comprising a grounded reference layer;

providing a signal layer;

photoetching the signal layer to define a circuit;

providing said PCB with a perimeter;

mounting said power supply and said GNSS receiver on said PCB;

connecting said power supply and said GNSS receiver to said positive and grounded reference layers;

providing multiple decoupling capacitors;

connecting each said capacitors to multiple said PCB layers and electrically closely-coupling said PCB layers with said capacitors;

determining optimal first and second RF paths from the antennas to the receiver;

aligning multiple said decoupling capacitors along said optimal RF paths and thereby creating first and second decoupling lines each extending from said receiver to said PCB edge in proximity to a respective antenna;

forming first and second isolation islands along said first and second decoupling line paths respectively;

providing first and second RF transmission lines connecting said receiver to said first and second antennas respectively; and

locating said first and second antennas in said first and second isolation islands respectively.

9. A tightly-coupled printed circuit board (PCB) circuit, which includes:

multiple conductive layers;

insulating layers separating said conductive layers;

a positive reference layer;

a ground plane comprising a grounded reference layer;

a signal layer;

a circuit photoetched in the signal layer;

multiple electrical components each connected to one or more layers;

a decoupling line in said PCB; and

an electrical isolation island formed by said decoupling line in said PCB.

10. The circuit of claim 9, which includes:

one of said components comprising a receiver;

said PCB including a perimeter;

said receiver being connected to said PCB; and

said decoupling line extending from said receiver to said PCB perimeter.

11. The circuit of claim 10, which includes:

said components including an antenna located in said isolation island; and

an RF transmission line connecting said antenna to said receiver.

12. The circuit of claim 11, which includes:

an optimal RF path from the antenna to the receiver,

said decoupling line generally following said optimal RF path; and

said isolation island being formed along said decoupling line path.

13. The circuit of claim 10, which includes:

said receiver being located in an interior area of said PCB;

a pair of said decoupling lines; and

said decoupling lines extending from said receiver to said PCB perimeter.

14. The circuit of claim 9, which includes:

said decoupling line being formed with a plurality of discrete decouplers each extending through said PCB layers.

15. The circuit of claim 11, which includes:

said PCB having three sections each terminating at an outer end;

said receiver being located centrally with said PCB sections extending outwardly therefrom;

three antennas each mounted in a respective section in proximity to its outer end;

a pair of said decoupling lines each extending from said receiver to a respective PCB section outer end; and

three said isolation islands each located in a respective PCB section and each having a respective antenna located therein.