Sampling technique for digital beam former

• US 7,068,733 B2
• Filed: 10/05/2001
• Issued: 06/27/2006
• Est. Priority Date: 02/05/2001
• Status: Expired due to Fees

• Current Assignee: Hughes Electronics Corporation (Rtx Corporation)
• Original Assignee: The DIRECTV Group, Inc. (AT&T, Inc.)
• Inventors: Chang, Donald C. D., Yung, Kar W., Von der Embse, Urban A.
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): Wong, Linda
• Application Number:
  US09/973,270
• Publication Number:
  US 20020106041A1
• Time in Patent Office: 1,726 Days
• Field of Search: 455/12.1, 370/281, 332/103, 342/371, 342/383
• US Class Current: 375/316
• CPC Class Codes: H04B 7/18515 Transmission equipment in satellites or space-based relays
• CPC Class Codes: H04B 7/2041 Spot beam multiple access
• CPC Class Codes: H04L 1/02 by diversity reception

Abstract

A mobile satellite payload 18 and a method for sampling communication signals 26 are provided. The mobile satellite payload 18 uses a plurality of receive radiating elements 24 within a phase array antenna 22 to convert the communication signals 26 to received signals [S(t)]. A plurality of low noise amplifiers (LNAs) 28 amplify the received signals [S(t)] to then be received by a plurality of analog-to-digital (A/D) converters 29. The A/D converters 29 transform the received signals [S(t)] into digital baseband signals [S″(t)].

Claims

1. A method of sampling communication signals within a mobile satellite payload having a phase array antenna, receive radiating elements, a plurality of low noise amplifiers (LNAs) and a plurality of analog-to-digital (A/D) converters, comprising:

receiving the communication signals with the receive radiating elements and forming received signals;

amplifying said received signals within the plurality of LNAs to form amplified received signals; and

downconverting said amplified received signals into digital baseband signals within the plurality of A/D converters by sampling the amplified received signals at a predetermined sampling frequency fs using A/D converters with an aperture time of 1/(A*fs), where A is a constant related to the A/D converters.

2. A method as in claim 1 further comprising filtering the amplified received signals within the plurality of A/D converters.

3. A method as in claim 1 further comprising sampling the amplified received signals at properly predetermined sampling rates.

4. A method as in claim 1 further comprising maintaining the accuracy of said plurality of A/D converters aperture times (α

).

5. A method as in claim 1 further comprising sampling the received signals at frequencies selected from the following group:

super high frequency band (SHF), L-band, S-band, and C-band and frequency bands above C band.

6. A method as in claim 1 further comprising automatically filtering said received signals within the plurality of A/D converters.

7. A mobile satellite payload comprising:

a phase array antenna, wherein said phase array antenna comprises a plurality of receive radiating elements for forming received signals;

a plurality of low noise amplifiers (LNAs) electrically coupled to said receive radiating elements for amplifying the received signals to form amplified received signals; and

a plurality of analog-to-digital (A/D) converters electrically coupled to said LNAs, wherein said plurality of A/D converters downconverting said amplified received signals into digital baseband signals by sampling the amplified received signals at a predetermined sampling frequency fs using A/D converters with an aperture time of 1/(A*fs), where A is a constant related to the A/D converters.

8. A system as in claim 7 wherein said plurality of A/D converters incorporate the function of a filter.

9. A system as in claim 7 wherein said plurality of A/D converters operates with various aperture times.

10. A system as in claim 7 wherein said plurality of A/D converters are able to perform as low pass or band pass filters.

11. A system as in claim 7 wherein said plurality of A/D converters are able to sample at different predetermined sampling rates.

12. A communication system comprising:

an antenna for receiving a received signal;

a low noise amplifier (LNA) electrically coupled to said antenna for amplifying the received signal to form an amplified received signal; and

an analog-to-digital (A/D) converter electrically coupled to said LNA, wherein said A/D converter downconverts the amplified received signal into a digital baseband signal by sampling the amplified received signals at a predetermined sampling frequency fs using a A/D converter with an aperture time of 1/(A*fs), where A is a constant related to the A/D converter.

13. A method of sampling communication signals within a mobile satellite payload having a phase array antenna, receive radiating elements, a plurality of low noise amplifiers (LNAs) and a plurality of analog-to-digital (A/D) converters, comprising:

receiving the communication signals through the use of the receive radiating elements and forming received signals;

amplifying said received signals within the plurality of LNAs to form amplified received signals;

downconverting said amplified received signals within the plurality of A/D converters;

sampling said amplified received signals within the plurality of A/D converters at a predetermined sampling frequency fs using A/D converters with an aperture time of 1/(A*fs), where A is a constant related to the A/D converters;

filtering said amplified received signals within the plurality of A/D converters;

wherein the combination of downconverting, sampling, and filtering said received signals transforms said amplified received signals into digital baseband signals.

14. A method as in claim 13 wherein sampling said amplified received signals comprises maintaining the accuracy of said plurality of A/D converters aperture times (α

).

15. A method as in claim 13 wherein sampling said amplified received signals comprises sampling the amplified received signals at properly predetermined sampling rates.