Blocker performance in a radio receiver

• US 7,545,889 B2
• Filed: 10/26/2005
• Issued: 06/09/2009
• Est. Priority Date: 10/26/2005
• Status: Expired due to Fees

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Li, Qiang Tom, Darabi, Hooman
• Primary Examiner(s): TSE, YOUNG TOI
• Application Number:
  US11/260,848
• Publication Number:
  US 20070092038A1
• Time in Patent Office: 1,322 Days
• Field of Search: 375/279, 375/281, 375/316, 375/320, 375/321, 375/329, 375/332, 375/344, 375/345, 455/192.1, 455/192.2, 455/195.1, 455/206, 455/339, 455/205, 455/150.1, 455/154.1, 455/189.1, 455/191.1, 455/340, 329/304, 329/306, 329/323, 329/346
• US Class Current: 375/332
• CPC Class Codes: H03H 11/1291 Current or voltage controlled filters

Abstract

Configuring a multiple stage band pass filter of a radio frequency receiver commences by setting a corner of a low pass mixer output filter that receives a down sampled analog information signal. Operation continues with setting a buffer output filter corner of a low pass buffer output filter coupled to an output of low pass mixer output filter via a buffer. Then, operation includes setting the poles and zero of a plurality of band pass filters coupled to the output of the low pass buffer output filter is performed. This operation includes first setting a zero of a respected band pass filter and then setting the plurality of poles of the band pass filter. Finally, operation concludes with setting a combined gain of the combination of the low pass mixer output filter, the low pass buffer output filter, and the plurality of band pass filters.

Claims

1. A method for configuring a multiple stage band pass filter of a Radio Frequency (RF) receiver comprising:

setting a corner of a low pass mixer output filter that receives a down sampled analog information signal;

setting a corner of a low pass buffer output filter coupled to an output of the low pass mixer output filter via a buffer;

for each of a plurality of band pass filters coupled to an output of the low pass buffer output filter;

setting a zero of the band pass filter; and

setting a plurality of poles of the band pass filter; and

setting a combined gain of the combination of the low pass mixer output filter, the low pass buffer output filter, and the plurality of band pass filters.

2. The method of claim 1, wherein setting the corner of the low pass mixer output filter that receives the down sampled analog information signal comprises setting a variable capacitor of the low pass mixer output filter.

3. The method of claim 1, wherein setting the corner of the low pass buffer output filter coupled to the output of the low pass mixer output filter via the buffer comprises setting a variable capacitor of the low pass buffer output filter.

4. The method of claim 1, wherein setting the zero of the band pass filter comprises setting at least one of a variable capacitor and a variable resistor of the band pass filter.

5. The method of claim 1, wherein setting the combined gain of the combination of the low pass mixer output filter, the low pass buffer output filter, and the plurality of band pass filters comprises setting a variable resistance of at least one of the plurality of band pass filters.

6. The method of claim 1, wherein setting the combined gain of the combination of the low pass mixer output filter, the low pass buffer output filter, and the plurality of band pass filters comprises enabling/disabling a transconductance element of at least one of the plurality of band pass filters.

7. The method of claim 1, wherein setting the combined gain of the combination of the low pass mixer output filter, the low pass buffer output filter, and the plurality of band pass filters comprises adjusting a biasing impedance of a transconductance element of at least one of the plurality of band pass filters.

8. The method of claim 1, wherein setting the combined gain of the combination of the low pass mixer output filter, the low pass buffer output filter, and the plurality of band pass filters comprises adjusting a biasing voltage of a transconductance element of at least one of the plurality of band pass filters.

9. A method for configuring a multiple stage band pass filter of a Radio Frequency (RF) receiver comprising:

setting a corner of an I branch low pass mixer output filter that receives an I component of a down sampled analog information signal;

setting a corner of a Q branch low pass mixer output filter that receives a Q component of the down sampled analog information signal;

setting a corner of an I branch low pass buffer output filter coupled to an output of the I branch low pass mixer output filter via an I branch buffer;

setting a corner of a Q branch low pass buffer output filter coupled to an output of the Q branch low pass mixer output filter via a Q branch buffer;

for each of a plurality of I branch band pass filters coupled to an output of the I branch low pass buffer output filter;

setting a zero of an I branch of the band pass filter; and

setting a plurality of poles of the I branch of the band pass filter;

for each of a plurality of Q branch band pass filters coupled to an output of the Q branch low pass buffer output filter;

setting a zero of a Q branch of the band pass filter; and

setting a plurality of poles of the Q branch of the band pass filter;

setting a combined gain of the combination of the I branch low pass mixer output filter, the I branch low pass buffer output filter, and the plurality of I branch band pass filters; and

setting a combined gain of the combination of the Q branch low pass mixer output filter, the Q branch low pass buffer output filter, and the plurality of Q branch band pass filters.

10. The method of claim 9, wherein:

setting the corner of the I branch low pass mixer output filter comprises setting a variable capacitor of the I branch low pass mixer output filter; and

setting the corner of the Q branch low pass mixer output filter comprises setting a variable capacitor of the Q branch low pass mixer output filter.

11. The method of claim 9, wherein:

setting the corner of the I branch low pass buffer output filter comprises setting a variable capacitor of the I branch low pass buffer output filter; and

setting the corner of the Q branch low pass buffer output filter comprises setting a variable capacitor of the Q branch low pass buffer output filter.

12. The method of claim 9, wherein:

setting the zero of the I branch band pass filter comprises setting at least one of a variable capacitor or a variable resistor of the I branch band pass filter; and

setting the zero of the Q branch band pass filter comprises setting at least one of a variable capacitor or a variable resistor of the Q branch band pass filter.

13. The method of claim 9, wherein setting the combined gain of the combination of the I or Q branch low pass mixer output filter, the I or Q branch low pass buffer output filter, and the plurality of I or Q branch band pass filters comprises setting a variable resistance of at least one of the plurality of band pass filters.

14. The method of claim 9, wherein:

setting the combined gain of the combination of the I branch low pass mixer output filter, the I branch low pass buffer output filter, and the plurality of I branch band pass filters comprises enabling/disabling a transconductance element of at least one of the plurality of I branch band pass filters; and

setting the combined gain of the combination of the Q branch low pass mixer output filter, the Q branch low pass buffer output filter, and the plurality of Q branch band pass filters comprises enabling/disabling a transconductance element of at least one of the plurality of Q branch band pass filters.

15. The method of claim 9, wherein:

setting the combined gain of the combination of the I branch low pass mixer output filter, the I branch low pass buffer output filter, and the plurality of I branch band pass filters comprises adjusting a biasing impedance of a transconductance element of at least one of the plurality of I branch band pass filters; and

setting the combined gain of the combination of the Q branch low pass mixer output filter, the Q branch low pass buffer output filter, and the plurality of Q branch band pass filters comprises adjusting a biasing impedance of a transconductance element of at least one of the plurality of Q branch band pass filters.

16. The method of claim 9, wherein:

setting the combined gain of the combination of the I branch low pass mixer output filter, the I branch low pass buffer output filter, and the plurality of I branch band pass filters comprises adjusting a biasing voltage of a transconductance element of at least one of the plurality of I branch band pass filters; and

setting the combined gain of the combination of the Q branch low pass mixer output filter, the Q branch low pass buffer output filter, and the plurality of Q branch band pass filters comprises adjusting a biasing voltage of a transconductance element of at least one of the plurality of Q branch band pass filters.

17. A multiple stage band pass filter of a Radio Frequency (RF) Integrated Circuit comprising:

an I branch low pass mixer output filter operable to receive an I component of a down sampled analog information signal;

an I branch buffer communicatively coupled to an output of the I branch low pass mixer output filter;

an I branch low pass buffer output filter communicatively coupled to an output of the I branch buffer;

a plurality of I branch band pass filters communicatively coupled to an output of the I branch low pass buffer output filter;

wherein the I branch low pass mixer output filter, the I branch low pass buffer output filter, and the plurality of I branch band pass filters are operable to be tuned to meet out of channel and out of band blocking requirements;

wherein the I branch low pass mixer output filter, the I branch low pass buffer output filter, and the plurality of I branch band pass filters are operable to be tuned to meet an in-channel gain requirement;

a Q branch low pass mixer output filter operable to receive a Q component of the down sampled analog information signal;

a Q branch buffer communicatively coupled to an output of the Q branch low pass mixer output filter;

a Q branch low pass buffer output filter communicatively coupled to an output of the Q branch buffer;

a plurality of Q branch band pass filters communicatively coupled to an output of the Q branch low pass buffer output filter;

wherein the Q branch low pass mixer output filter, the Q branch low pass buffer output filter, and the plurality of Q branch band pass filters are operable to be tuned to meet the out of channel and the out of band blocking requirements; and

wherein the Q branch low pass mixer output filter, the Q branch low pass buffer output filter, and the plurality of Q branch band pass filters are operable to be tuned to meet the in-channel gain requirement.

18. The multiple stage band pass filter of claim 17, wherein:

at least one of the plurality of I branch band pass filters comprises a plurality of transconductance elements and at least one low pass filter; and

at least one of the plurality of Q branch band pass filters comprises a plurality of transconductance elements and at least one low pass filter.

19. The multiple stage band pass filter of claim 18, wherein:

one of the transconductance elements of the plurality of I branch band pass filters is operable to be enabled/disabled to adjust a gain of the corresponding I branch band pass filter; and

one of the transconductance elements of the plurality of Q branch band pass filters is operable to be enabled/disabled to adjust a gain of the corresponding Q branch band pass filter.

20. The multiple stage band pass filter of claim 18, wherein:

one of the transconductance elements of the plurality of I branch band pass filters is operable to have its biasing impedance altered to adjust a gain of the corresponding I branch band pass filter; and

one of the transconductance elements of the plurality of Q branch band pass filters is operable to have its biasing impedance altered to adjust a gain of the corresponding Q branch band pass filter.

21. The multiple stage band pass filter of claim 18, wherein:

one of the transconductance elements of the plurality of I branch band pass filters is operable to have its biasing voltage altered to adjust a gain of the corresponding I branch band pass filter; and

one of the transconductance elements of the plurality of Q branch band pass filters is operable to have its biasing voltage altered to adjust a gain of the corresponding Q branch band pass filter.

22. A multiple stage band pass filter of a Radio Frequency (RF) Integrated Circuit comprising:

a low pass mixer output filter operable to receive a down sampled analog information signal;

a buffer communicatively coupled to an output of the low pass mixer output filter;

a low pass buffer output filter communicatively coupled to an output of the buffer; and

a plurality of band pass filters communicatively coupled to an output of the low pass buffer output filter,

wherein the low pass mixer output filter, the low pass buffer output filter, and the plurality of band pass filters are operable to be tuned to meet out of channel and out of band blocking requirements, and

wherein the low pass mixer output filter, the low pass buffer output filter, and the plurality band pass filters are operable to be tuned to meet in-channel gain requirements.

23. The multiple stage band pass filter of claim 22, wherein at least one of the plurality of band pass filters comprises a plurality of transconductance elements and at least one low pass filter.

24. The multiple stage band pass filter of claim 23, wherein one of the transconductance elements of the plurality of band pass filters is operable to be enabled/disabled to adjust a gain of the corresponding band pass filter.

25. The multiple stage band pass filter of claim 23, wherein one of the transconductance elements of the plurality of band pass filters is operable to have its biasing impedance altered to adjust a gain of the corresponding band pass filter.

26. The multiple stage band pass filter of claim 23, wherein one of the transconductance elements of the plurality of band pass filters is operable to have its biasing voltage altered to adjust a gain of the corresponding band pass filter.