Load board for testing of RF chips

• US 6,791,317 B1
• Filed: 12/02/2002
• Issued: 09/14/2004
• Est. Priority Date: 12/02/2002
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Liu, Henry, Walsh, Stephen
• Primary Examiner(s): TANG, MINH NHUT
• Application Number:
  US10/307,738
• Time in Patent Office: 652 Days
• Field of Search: 324/73.1, 324/754-755, 324/158.1, 439/63, 439/65, 439/74-75, 439/581, 333/260
• US Class Current: 324/756.02
• CPC Class Codes: G01R 1/045 Sockets or component fixtures for RF or HF testing
• CPC Class Codes: G01R 31/2822 of microwave or radiofrequency circuits of attenuation, gain, e.g. using network analyzers G01R27/28
• CPC Class Codes: G01R 31/2889 Interfaces, e.g. between probe and tester G01R31/31905 and G01R1/07364 take precedence

Abstract

A load board for connecting an RF integrated circuit device (“DUT”) to a tester for testing. The load board includes a PCB having a DUT side and a non-DUT side. The DUT is insertable to a socket on the DUT side. The non-DUT side is accessible to one or more RF connectors to which an RF cable is connectable. Each RF connector provides an RF connection to a tester. The PCB includes at least one aperture through which a coaxial connection may be made to a cable connected to one of the RF connectors. Each coaxial connection through each aperture is electrically coupled on the DUT side to the DUT socket and matched for a range of frequencies up to at least approximately 5 GHz, including the frequencies used in the IEEE 802.11a standard.

Claims

1. A load board for connecting to a tester for testing an RF integrated circuit device (“

DUT”

), the load board comprising;

a printed circuit board (“

PCB”

) having a DUT side and a non-DUT side, the DUT side including a socket into which a DUT is insertable, the non-DUT side accessible to one or more RF connectors to which an RF cable is connectable, each RF connector providing an RF connection to a tester such that RF signals can be input to or output from the tester from or to the DUT inserted in the socket, the PCB further including at least one aperture for making a coaxial connection therethrough to a cable connected to one of the RF connectors, each coaxial connection through each aperture electrically coupled to the socket on the DUT side of the PCB and matched for a range of frequencies up to at least approximately 5 GHz, including the frequencies used in the IEEE 802.11a standard.

2. A load board as recited in claim 1, wherein the range of frequencies is up to at least approximately 5.8 GHz.

3. A load board as recited in claim 2, further comprising:

a frame onto which the PCB is attached, the frame including the RF connectors on the non-DUT side.

4. A load board as recited in claim 2, wherein the PCB includes an end launch connector on one edge of the aperture through which there is a coaxial connection, the end launch connector electrically connected to the socket and matched for the range of frequencies up to at least 5.8 GHz, such that the coaxial connection through the aperture is via the end launch connector at the edge of the aperture.

5. A load board as recited in claim 4, wherein the end launch connector is an SMA connector.

6. A load board as recited in claim 4, wherein the end launch connector is an off-the-shelf end launch connector, and wherein region around the edge of the aperture where the end launch connector is mounted is thinned out to accommodate the off-the-shelf end-launch connector.

7. A load board as recited in claim 6, wherein the PCB is a multilayer PCB and wherein the thinned out region has fewer layers than the non-thinned out areas of the PCB.

8. A load board as recited in claim 4, further including a 90 degree adapter attached to the end launch connector, such that the 90 degree adapter provides for a cable to be attached between the 90 degree adapter and one of the RF connectors on the non-DUT side.

9. A load board as recited in claim 4, wherein a cable is attached between the end launch connector and a particular one of the RF connectors on the non-DUT side through the aperture of the end launch connector.

10. A load board as recited in claim 2, wherein the coaxial connection through each aperture uses a semi rigid coaxial RF cable bent in a smooth manner to avoid RF mismatch, the cable soldered onto traces on the DUT side of the PCB, and placed through the aperture to carry an RF signal to or from the DUT side from or to the non-DUT side of the PCB.

11. A load board for connecting to a tester for testing an RF integrated circuit device (“

DUT”

), the load board comprising;

a printed circuit board (“

PCB”

) having a DUT side and a non-DUT side, the DUT side including a socket into which a DUT is insertable, the non-DUT side accessible to one or more RF connectors to which an RF cable is connectable, each RF connector providing an RF connection to a tester such that RF signals can be input to or output from the tester from or to a DUT inserted in the socket, the PCB further including at least one aperture having an end launch connector on one edge on the DUT side, the aperture for making a coaxial connection from the end launch connector on the DUT side through the aperture to one of the RF connectors on the non-DUT side, the end launch connector electrically coupled to the socket and matched for a range of frequencies up to at least approximately 5 GHz, including the frequencies used in the IEEE 802.11a standard.

12. A load board as recited in claim 11, wherein the range of frequencies is up to at least approximately 5.8 GHz.

13. A load board as recited in claim 12, wherein the end launch connector is an SMA connector, and the range of frequencies is up to at least 15 GHz.

14. A load board as recited in claim 13, wherein the range of frequencies is up to at least approximately 18 GHz.

15. A load board as recited in claim 11, further comprising:

a frame onto which the PCB is attached, the frame including the RF connectors on the non-DUT side.

16. A load board as recited in claim 11, wherein the end launch connector is an off-the-shelf end launch connector, and wherein region around the edge of the aperture where the end launch connector is mounted is thinned out to accommodate the off-the-shelf end-launch connector.

17. A load board as recited in claim 16, wherein the PCB is a multilayer PCB and wherein the thinned out region has fewer layers than the non-thinned out areas of the PCB.

18. A load board as recited in claim 11, further including a 90 degree adapter attached to the end launch connector, such that the 90 degree adapter provides for a cable to be attached between the 90 degree adapter and one of the RF connectors on the non-DUT side.

19. A load board as recited in claim 11, wherein a cable is attached between the end launch connector and one of the RF connectors on the non-DUT side through the aperture of the end launch connector.

20. A board for connecting to a means for testing an RF integrated circuit device (“

DUT”

), the board comprising;

a DUT side and a non-DUT side, the DUT side including a socket means into which a DUT is insertable, the non-DUT side accessible to a first means for connecting onto which a first end of an RF cable is connectable, the RF cable having a second end, the first means for connecting providing an RF connection to a means for testing the DUT;

an aperture having an edge; and

a second means for connecting onto which the second end of the RF cable is connectable, the second means for connecting located at the edge of the aperture and electrically coupled to the socket means on the DUT side of the board, the socket means and the second means for connecting coupled hereto matched for a range of frequencies up to at least approximately 5 GHz, including the frequencies used in the IEEE 802.11a standard,

such that a cable connected at its second end to the second means for connecting, passing through the aperture, and connected to the first means for connecting provides an RF connection between the DUT in the socket means and the means for testing.

21. A method for connecting radio frequency signals from a first side (“

DUT side”

) of a load board to the second side (“

non-DUT side”

) of the load board, the load board for connecting to a tester for testing an RF integrated circuit device (“

DUT”

), the load board including a socket on the DUT side into which the DUT is insertable, the method comprising;

providing at least one aperture on the load board;

making a coaxial connection from the DUT side of the load board to the non-DUT side of the load board through the aperture, such that the coaxial connection has a DUT end and a non-DUT end;

electrically coupling the DUT end of the coaxial connection with the socket; and

matching the coaxial connection for a range of frequencies up to at least approximately 5 GHz, including the frequencies of the IEEE 802.11a standard, the non-DUT end of the coaxial connection being accessible to one of a set of one or more RF connectors onto which an RF cable is connectable, each RF connector providing an RF connection to the tester, the coaxial connection through the aperture provided by a cable connected to one of the RF connectors,

such that the method provides RF signals in the range of frequencies to be input to or output from the tester from or to the DUT inserted in the socket.

22. A method as recited in claim 21, further comprising:

mounting an end launch connector on an edge of the aperture through which there is the coaxial connection, the end launch connector electrically coupled to the socket and matched for the range of frequencies up to at least 5.8 GHz, such that the electrical coupling on the DUT side of the coaxial connection with the socket is via the end launch connector at the edge of the aperture.