Granted Patent B2

US 7,139,684 · App. 11/285,447 · Granted Nov 21, 2006

Abstract

Claims (52)

1. A method for digitizing a signal, comprising the steps of:

receiving an analog signal spanning a frequency range;

splitting the received analog signal into a plurality of split signals, each spanning a frequency range smaller than the original frequency range;

translating the frequency range of at least one of the split signals;

digitizing each of said split signals;

converting the frequency range of the at least one translated split signal back to the original frequency range prior to converting the translated split signal;

equalizing each of said split signals to compensate for non-ideal magnitude and phase characteristics resulting from processing the received analog signal and digitized split signals; and

combining said digitized split signals mathematically to form a single output data stream that is a substantially correct representation of the received analog signal over the original frequency range.

2. A method for digitizing a signal, comprising the steps of:

receiving an analog signal spanning a frequency range;

splitting the received analog signal into a plurality of split signals, each spanning a frequency range smaller than the original frequency range;

translating the frequency range of at least one of the split signals;

digitizing each of said split signals;

converting the frequency range of the at least one translated split signal back to the original frequency range prior to converting the translated split signal;

passing the translated split signal through an image reject filter, having a predetermined passband; and

combining said digitized split signals mathematically to form a single output data stream that is a substantially correct representation of the received analog signal over the original frequency range.

3. The method of claim 2 , wherein the predetermined passband comprises an intrinsic bandwidth of a channel used for digitizing said translated spilt signal.

4. A method for digitizing a signal, comprising the steps of:

receiving an analog signal;

splitting the received analog signal into channels having a low frequency split signal and a high frequency split signal respectively;

mixing said high frequency split signal with a first predetermined periodic function with a predetermined frequency;

band limiting each of the split signals to a predetermined band range;

digitizing said split signals;

mixing said digitized high frequency split signal with a second predetermined periodic function with said predetermined frequency, resulting in two images of said high frequency split signal at different frequencies;

passing said mixed, digitized high frequency split signal through an image reject filter, having a second predetermined frequency, to remove an unwanted lower frequency from one of the two images; and

combining said digitized low frequency split signal and the higher frequency image of the digitized high frequency split signal to form a single output data stream that is a substantially correct representation of the received analog signal.

5. The method of claim 4 , further comprising the step of equalizing the low frequency and the high frequency split signals separately to compensate for non-ideal magnitude and phase characteristics introduced by front-end systems for each channel.

6. The method of claim 4 , wherein said predetermined periodic functions are low-distortion sinusoids.

7. An apparatus for digitizing a signal, comprising:

an input adapted to receive an analog signal spanning a frequency range;

a splitter adapted to receive the analog signal and split the received analog signal into a plurality of split signals, each split signal spanning a frequency range smaller than the original frequency range;

a first mixer to translate the frequency range of at least one of the split signals;

a digitizer to digitize each of said split signals;

a second mixer to translate the frequency range of the at least one digitized translated split signal back to the original frequency range prior to translating the digitized translated signal; and

a combining unit for combining said digitized split signals mathematically to form a single output data stream that is a substantially correct representation of the received analog signal over the original frequency range.

8. The apparatus of claim 7 , further comprising an equalizer to equalize each of said digitized split signals to compensate for non-ideal magnitude and phase characteristics resulting from processing the received analog signal and digitized split signals.

9. The apparatus of claim 7 , further comprising a band limiter for band limiting each of the split signals to a corresponding one of a plurality of predetermined band ranges before translating.

10. The apparatus of claim 7 , further comprising an image reject filter having a predetermined passband for receiving and passing the translated split signal.

11. The apparatus of claim 10 , wherein the predetermined passband comprises an intrinsic bandwidth of a channel used for digitizing said translated split signal.

12. The apparatus of claim 7 , wherein said translating is accomplished by a sampling action of a digitizer used for digitizing said at least one split signal.

13. The apparatus of claim 7 , wherein at least one of the first and second mixers uses a low-distortion sinusoid for frequency translation.

14. An apparatus for digitizing a signal, comprising:

an input adapted to receive an analog signal;

a splitter adapted to receive the analog signal, and to split the received analog signal into channels having a low frequency split signal and a high frequency split signal respectively;

a first mixer to mix said high frequency split signal with a first predetermined periodic function with a predetermined frequency;

a band limiter adapted to band limit each of the split signals to a predetermined band range;

a digitizer to digitize said split signals;

a second mixer to mix said digitized high frequency split signal with a second predetermined periodic function with said predetermined frequency, resulting in two images of said digitized high frequency split signal at different frequencies;

an image reject filter, having a second predetermined frequency, for receiving and passing said digitized high frequency split signal to remove an unwanted lower frequency from one of the two images; and

a combining unit to combine said digitized low frequency split signal and said high frequency image of said digitized high frequency split signal to form a single output data stream that is a substantially correct digital representation of the received analog signal.

15. The apparatus of claim 14 , further comprising an equalizer for equalizing the high frequency and the low frequency split signals separately to compensate for non-ideal magnitude and phase characteristics introduced by front-end systems for each channel.

16. The apparatus of claim 14 , wherein said predetermined periodic functions are low-distortion sinusoids.

Assignments (6)