Routing and shielding of signal lines to improve isolation

Patent metadata

Field	Value
Publication number	US-9277641-B2
Application number	US-201313857022-A
Country	US
Kind code	B2
Filing date	Apr 4, 2013
Priority date	Apr 4, 2013
Publication date	Mar 1, 2016
Grant date	Mar 1, 2016

Abstract

Techniques for routing and shielding signal lines to improve isolation between the signal lines are disclosed. In an exemplary design, an apparatus includes first, second, and third signal lines and a switch. The first, second, and third signal lines are configurable to carry first, second, and third signals, respectively. The switch is coupled between the second signal line and AC ground and is closed when the second signal line is not carrying the second signal. The second signal line isolates the first and third signal lines when the switch is closed. Adjacent signal lines are not active at the same time. A signal line may include positive and negative signal lines, which may have at least one cross over in order to cancel coupling between the positive and negative signal lines.

First claim

What is claimed is:

1. An apparatus comprising:
a first signal line configurable to carry a first signal associated with a first set of carrier signals;
a second signal line configurable to carry a second signal associated with a second set of carrier signals;
a third signal line configurable to carry a third signal; and
a first switch coupled between the second signal line and alternating current (AC) ground, the second signal line configured to isolate the first and third signal lines when the first switch is closed.

2. The apparatus of claim 1 , wherein the first and second signal lines are not active concurrently, and the second and third signal lines are not active concurrently.

3. The apparatus of claim 1 , wherein the first switch comprises an N-channel metal oxide semiconductor (NMOS) transistor having a source coupled to the AC ground and a drain coupled to the second signal line.

4. The apparatus of claim 1 , further comprising:
a fourth signal line configurable to carry a fourth signal, the third signal line being located between the second and fourth signal lines.

5. The apparatus of claim 4 , wherein the first and second signal lines are configurable to carry the first and second signals from two antennas for a first band group, and the third and fourth signal lines are configurable to carry the third and fourth signals from the two antennas for a second band group.

6. The apparatus of claim 4 , wherein the second and third signal lines are configurable to carry the second and third signals from two antennas for a first band group, and the first and fourth signal lines are configurable to carry the first and fourth signals from the two antennas for a second band group.

7. The apparatus of claim 4 , further comprising:
a second switch coupled between the third signal line and the AC ground, the third signal line configured to isolate the second and fourth signal lines when the second switch is closed.

8. The apparatus of claim 4 , further comprising:
a fifth signal line configurable to carry a fifth signal; and
a sixth signal line configurable to carry a sixth signal, the first, second, third, fourth, fifth and sixth signal lines comprising a first pair of signal lines for a first band group, a second pair of signal lines for a second band group, and a third pair of signal lines for a third band group.

9. The apparatus of claim 1 , wherein the first signal line comprises positive and negative signal lines having at least one cross over.

10. The apparatus of claim 1 , wherein the first signal line comprises a first pair of positive and negative signal lines having an even number of cross over, and the second signal line comprises a second pair of positive and negative signal lines having an odd number of cross over.

11. The apparatus of claim 1 , further comprising:
a second switch coupled between the second signal line and the AC ground, the first switch and the second switch being closed when the second signal line is not carrying the second signal.

12. The apparatus of claim 1 , wherein the first signal line is configurable to carry the first signal from a first amplifier to a first downconverter, the second signal line is configurable to carry the second signal from a second amplifier to a second downconverter, and the third signal line is configurable to carry the third signal from a third amplifier to a third downconverter.

13. The apparatus of claim 12 , wherein the first, second, and third amplifiers are implemented on a first integrated circuit (IC) chip, and the first, second, and third downconverters are implemented on a second IC chip.

14. A method comprising:
generating a first signal for transmission via a first signal line associated with a first set of carrier signals;
shorting a second signal line to alternating current (AC) ground when the second signal line is not carrying a second signal, the second signal line associated with a second set of carrier signals; and
generating a third signal for transmission via a third signal line, the second signal line configured to isolate the first and third signal lines when the second signal line is shorted to the AC ground.

15. The method of claim 14 , further comprising:
generating a fourth signal for transmission via a fourth signal line; and
shorting the third signal line to the AC ground when the third signal line is not carrying the third signal, the third signal line configured to isolate the second and fourth signal lines when the third signal line is shorted to the AC ground.

16. The method of claim 15 , wherein the second and third signals are generated for a first band group based on received signals from two antennas, and the first and fourth signals are generated for a second band group based on the received signals from the two antennas.

17. The method of claim 15 , wherein the first and second signals are generated for a first band group based on received signals from two antennas, and the third and fourth signals are generated for a second band group based on the received signals from the two antennas.

18. An apparatus comprising:
means for generating a first signal for transmission via a first signal line associated with a first set of carrier signals;
means for shorting a second signal line to alternating current (AC) ground, the second signal line associated with a second set of carrier signals; and
means for generating a third signal for transmission via a third signal line, the second signal line configured to isolate the first and third signal lines when the second signal line is shorted to the AC ground via the means for shorting the second signal line.

19. The apparatus of claim 18 , further comprising:
means for generating a fourth signal for transmission via a fourth signal line; and
means for shorting the third signal line to the AC ground, the third signal line configured to isolate the second and fourth signal lines when the third signal line is shorted to the AC ground via the means for shorting the third signal line.

Assignees

• Qualcomm Inc

Inventors

• Youssef Ahmed Abdel Monem
• Chang Li-Chung
• Abdel Ghany Ehab Ahmed Sobhy
• Xu Rui
• Leung Wingching Vincent
• He Allen

Classifications

• H05K2201/09245

  Crossing layout · CPC title

• H04B1/005

  adapting radio receivers, transmitters andtransceivers for operation on two or more bands, i.e. frequency ranges · CPC title

• H04B3/02

  Details · CPC title

• H05K1/0228 Primary

  Compensation of cross-talk by a mutually correlated lay-out of printed circuit traces, e.g. for compensation of cross-talk in mounted connectors (balanced signal pairs H05K1/0245) · CPC title

• H05K1/0219

  Printed shielding conductors for shielding around or between signal conductors, e.g. coplanar or coaxial printed shielding conductors · CPC title