PHASED-ARRAY TRANSCEIVER FOR MILLIMETER-WAVE FREQUENCIES

• US 20110063169A1
• Filed: 03/30/2010
• Published: 03/17/2011
• Est. Priority Date: 09/13/2009
• Status: Active Grant

• Current Assignee: International Business Machines Corporation, MediaTek, Inc.
• Original Assignee: International Business Machines Corporation
• Inventors: Floyd, Brian A., Valdes-Garcia, Alberto, CHEN, PING-YU, Reynolds, Scott K., Tsai, Ming-Dai, Natarajan, Arun S., Zhan, Jing-Hong C., Lai, Jie-Wei, Nicolson, Sean T.
• Granted Patent: US 8,618,983 B2
• Time in Patent Office: Days
• US Class Current: 342/368
• CPC Class Codes: H01Q 3/267 Phased-array testing or checking devices
• CPC Class Codes: H01Q 3/2694 using also variable phase-shifters H01Q3/2688 takes precedence

Abstract

A phased-array transmitter and receiver that may be effectively implemented on a silicon substrate. The transmitter distributes to front-ends, and the receiver combines signals from front-ends, using a power distribution/combination tree that employs both passive and active elements. By monitoring the power inputs and outputs, a digital control is able to rapidly provide phase and gain correction information to the front-ends. Such a transmitter/receiver includes a plurality of radio frequency (RF) front-ends and a power splitting/combining network that includes active and passive components configured to distribute signals to/from the front-ends.

Claims

1. A phased-array transmitter having beam-steering ability, comprising:

a plurality of radio frequency (RF) front-ends, each configured to transmit a signal with a given phase relative to the others such that the amplitude of the transmitted signal is highest in a given direction, the front-ends comprising;

a phase shifter configured to delay the signal in accordance with the given direction; and

a variable amplifier configured to adjust the gain of the signal; and

a power distribution network configured to accept an RF signal from an up-conversion element and to selectively pass the RF signal to one or more of the RF front-ends, wherein the power distribution network includes a combination of active and passive components.

2. The transmitter of claim 1, wherein the RF front-ends further comprise a digital beam table configured to adjust the phase shifter'"'"'s phase delay and the variable amplifier'"'"'s gain.

3. The transmitter of claim 2, wherein the RF front-ends further comprise a power sensor configured to measure each front-end'"'"'s power output.

4. The transmitter of claim 3, further comprising a digital control configured to determine an optimal phase delay and gain for each front end and to provide that information to the beam table of each front-end.

5. The transmitter of claim 4, wherein the digital control is further configured to account for manufacturing and environmental variations in its determination of optimal phase delay and gain.

6. The transmitter of claim 4, further comprising a multiplexer configured to accept the power measurements from each front-end'"'"'s power sensor and further configured to output any individual power signal or an aggregation of all power outputs.

7. The transmitter of claim 1, wherein each phase shifter comprises:

a passive phase shifter configured to provide continuous a 180 degree range of phase shift; and

a differential phase-inverting amplifier configured to provide an additional 180 degrees of discrete phase shift and variable gain amplification.

8. The transmitter of claim 1, wherein the power distribution network comprises:

one or more modified Gysel splitters, configured to passively split a signal; and

one or more active distribution amplifiers, configured to amplify and split a signal.

9. The transmitter of claim 1, further comprising a buffer configured to provide loopback information to an associated receiver.

10. The transmitter of claim 1, wherein the phased-array transmitter is formed on an integrated circuit chip.

11. A phased-array receiver having beam-steering ability, comprising:

a plurality of radio frequency (RF) front-ends, each configured to receive a signal with a given delay relative to the others such that the gain of the received signal is highest in a given direction, comprising;

a phase shifter configured to delay the signal in accordance with the given direction; and

a variable amplifier configured to adjust the gain of the signal; and

a power combination network configured to accept an RF signal from each of the RF front-ends and to pass a combined RF signal a down-conversion element, wherein the power distribution network includes a combination of active and passive components.

12. The receiver of claim 11, wherein the RF front-ends further comprise a digital beam table configured to adjust the phase shifter'"'"'s phase delay and the variable amplifier'"'"'s gain.

13. The receiver of claim 11, further comprising, a received signal strength indicator configured to detect the power output of the power combination network.

14. The receiver of claim 13, further comprising a digital control configured to adjust the gain of the variable amplifiers of the front-ends based on the detected power output.

15. The receiver of claim 11, wherein each phase shifter comprises:

a passive phase shifter configured to provide a continuous 180 degree range of phase shift; and

a differential phase-inverting amplifier configured to provide an additional 180 degrees of discrete phase shift and variable gain amplification.

16. The receiver of claim 11, wherein the power combination network comprises:

one or more modified Gysel combiners, configured to passively combine a plurality of signals; and

one or more active power combiners, configured to combine a plurality of signals and amplify the combined signal.

17. The receiver of claim 11, further comprising a loopback variable gain amplifier, configured to receive loopback information from an associated transmitter and to calibrate in-phase/quadrature gain.

18. The receiver of claim 11, wherein the phased-array receiver is formed on an integrated circuit chip.

19. A method for beam-steering in a phased-array transmitter implemented on a silicon substrate, comprising the steps of:

distributing a signal to a plurality of transmitter front-ends;

phase shifting the signal at each transmitter front-end such the transmitter outputs interfere to produce a directed beam;

measuring the power output of each front-end; and

adjusting an amplification gain of each of the front-ends based on the measured power output to compensate for deviations from an optimal power output.

20. The method of claim 19, further comprising the step of monitoring environmental conditions, wherein the step of adjusting further adjusts the amplification gain of the front-ends based on said environmental conditions.

21. The method of claim 19, wherein said step of phase shifting directs the beam to avoid obstacles in the line of sight.

22. A method for beam-steering in a phased-array receiver implemented on a silicon substrate, comprising the steps of:

receiving a signal at a plurality of receiver front-ends;

phase shifting the signal at each front-end such the received signals interfere to produce a directed receiver gain;

combining the signals from the front-ends;

measuring the total power of the combined signals; and

adjusting an amplification gain of each of the front-ends based on the measured power output to compensate for deviations from an optimal power output.

23. The method of claim 22 further comprising the step of monitoring environmental conditions, wherein the step of adjusting further adjusts the amplification gain of the front-ends based on said environmental conditions.

24. The method of claim 22, wherein said step of phase shifting directs the receiver gain to avoid obstacles in the line of sight.