Hybrid low pass diplex filter

• US 7,508,284 B2
• Filed: 08/30/2006
• Issued: 03/24/2009
• Est. Priority Date: 08/30/2006
• Status: Active Grant

• Current Assignee: PPC Broadband Incorporated (Belden Inc.)
• Original Assignee: John Mezzalingua Associates Incorporated
• Inventors: Shafer, Steven
• Primary Examiner(s): Chang; Daniel D
• Application Number:
  US11/468,640
• Publication Number:
  US 20080055017A1
• Time in Patent Office: 937 Days
• Field of Search: 333/132, 333/175, 333/176, 333/172, 333/174, 333/185
• US Class Current: 333/132
• CPC Class Codes: H03H 2007/013 Notch or bandstop filters
• CPC Class Codes: H03H 2250/00 Indexing scheme relating to dual- or multi-band filters
• CPC Class Codes: H03H 7/0115 comprising only inductors and capacitors H03H7/075, H03H7/09, H03H7/12, H03H7/13 take precedence
• CPC Class Codes: H03H 7/175 Series LC in series path H03H7/1783 takes precedence
• CPC Class Codes: H03H 7/1758 Series LC in shunt or branch path H03H7/1791 takes precedence
• CPC Class Codes: H03H 7/1766 Parallel LC in series path H03H7/1783 takes precedence
• CPC Class Codes: H03H 7/1783 Combined LC in series path
• CPC Class Codes: H03H 7/1791 Combined LC in shunt or branch path

Abstract

A hybrid diplex bandstop filter includes a lowpass filter circuit which passes a first range of frequencies and a highpass filter circuit passes a third range of frequencies. The filter blocks a second range of frequencies. The third range of frequencies is higher than the second range and the first range. A tuning circuit tunes at least one re-resonance of a frequency inside the first range of frequencies to either within the second range of frequencies or outside an industry specified upper limit which is in the third range of frequencies.

Claims

1. A hybrid diplex bandstop filter;

comprising;

means for allowing a first range of frequencies to pass through the filter from an input to an output;

means for blocking a second range of frequencies from passing through the filter from the input to the output, wherein the second range of frequencies is higher than the first range of frequencies;

means for allowing a third range of frequencies to pass through the filter from the input to the output;

wherein the third range of frequencies is higher than the second range of frequencies; and

tuning means for tuning at least one re-resonance of a frequency within the first range of frequencies to either within the second range of frequencies or outside an industry specified upper limit within the third range of frequencies.

2. A filter according to claim 1, wherein the tuning means includes an inductor in series between a capacitor shunt pole and a ground.

3. A filter according to claim 1, wherein the tuning means includes a tank circuit in series between a capacitor shunt pole and a ground.

4. A filter according to claim 1, wherein the tuning means includes a first tank circuit in series with a second tank circuit, the first tank circuit includes an inductor in series with a capacitor, and the tuning means further includes a tank circuit in series between a capacitor shunt pole and a ground.

5. A filter according to claim 1, wherein the tuning means includes a first tank circuit in series with a second tank circuit, the first tank circuit includes an inductor in series with a capacitor, and the tuning means further includes a tank circuit in series between all capacitor shunt poles and a ground.

6. A filter according to claim 1, wherein the tuning means includes a first tank circuit in series with a second tank circuit and the tuning means further includes a tank circuit in series between a capacitor shunt pole and a ground.

7. A filter according to claim 1, wherein the tuning means includes a first tank circuit in series with a second tank circuit, the first tank circuit includes an inductor in series with a first capacitor, the second tank circuit includes an inductor in series with a second capacitor, and the tuning means further includes a tank circuit in series between a capacitor shunt pole and a ground.

8. A filter according to claim 1, wherein the tuning means includes a first tank circuit in series with a second tank circuit, the first tank circuit includes an inductor in series with a first capacitor, the second tank circuit includes an inductor in series with a second capacitor, and the tuning means further includes a tank circuit in series between all capacitor shunt poles and a ground.

9. A filter according to claim 1, wherein the industry specified upper limit is 1.0 GHz.

10. A hybrid diplex bandstop filter;

comprising;

a lowpass filter circuit which allows a first range of frequencies to pass through the filter from an input to an output;

a bandstop circuit which blocks a second range of frequencies from passing through the filter from the input to the output, wherein the second range of frequencies is higher than the first range of frequencies;

a highpass filter circuit which allows a third range of frequencies to pass through the filter from the input to the output, wherein the third range of frequencies is higher than the second range of frequencies; and

a tuning circuit which tunes at least one re-resonance of a frequency within the first range of frequencies to either within the second range of frequencies or outside an industry specified upper limit within the third range of frequencies.

11. A filter according to claim 10, wherein the tuning circuit includes an inductor in series between a capacitor shunt pole and a ground.

12. A filter according to claim 10, wherein the tuning circuit includes a tank circuit in series between a capacitor shunt pole and a ground.

13. A filter according to claim 10, wherein the tuning circuit includes a first tank circuit in series with a second tank circuit, the first tank circuit includes an inductor in series with a capacitor, and the tuning means further includes a tank circuit in series between a capacitor shunt pole and a ground.

14. A filter according to claim 10, wherein the tuning circuit includes a first tank circuit in series with a second tank circuit, the first tank circuit includes an inductor in series with a capacitor, and the tuning means further includes a tank circuit in series between all capacitor shunt poles and a ground.

15. A filter according to claim 10, wherein the tuning circuit includes a first tank circuit in series with a second tank circuit and the tuning means further includes a tank circuit in series between a capacitor shunt pole and a ground.

16. A filter according to claim 10, wherein the tuning circuit includes a first tank circuit in series with a second tank circuit, the first tank circuit includes an inductor in series with a first capacitor, the second tank circuit includes an inductor in series with a second capacitor, and the tuning means further includes a tank circuit in series between a capacitor shunt pole and a ground.

17. A filter according to claim 10, wherein the tuning circuit includes a first tank circuit in series with a second tank circuit, the first tank circuit includes an inductor in series with a first capacitor, the second tank circuit includes an inductor in series with a second capacitor, and the tuning means further includes a tank circuit in series between all capacitor shunt poles and a ground.

18. A filter according to claim 10, wherein the industry specified upper limit is 1.0 GHz.

19. A method of manufacturing a hybrid bandstop filter;

comprising the steps of;

making a lowpass filter circuit which allows a first range of frequencies to pass through the filter from an input to an output;

making a bandstop filter circuit which prevents a second range of frequencies from passing through the filter from the input to the output;

wherein the second range of frequencies is higher than the first range of frequencies;

making a highpass filter circuit which allows a third range of frequencies to pass through the filter from the input to the output, wherein the third range of frequencies is higher than the second range of frequencies; and

making a tuning circuit which tunes at least one re-resonance of a frequency within the first range of frequencies to either within the second range of frequencies or outside an industry specified upper limit within the third range of frequencies.

20. A method according to claim 19, wherein the tuning circuit includes an inductor in series between a capacitor shunt pole and a ground.

21. A method according to claim 19, wherein the tuning circuit includes a tank circuit in series between a capacitor shunt pole and a ground.

22. A method according to claim 19, wherein the tuning circuit includes a first tank circuit in series with a second tank circuit, the first tank circuit includes an inductor in series with a capacitor, and the tuning means further includes a tank circuit in series between a capacitor shunt pole and a ground.

23. A method according to claim 19, wherein the tuning circuit includes a first tank circuit in series with a second tank circuit, the first tank circuit includes an inductor in series with a capacitor, and the tuning means further includes a tank circuit in series between all capacitor shunt poles and a ground.

24. A method according to claim 19, wherein the tuning circuit includes a first tank circuit in series with a second tank circuit and the tuning means further includes a tank circuit in series between a capacitor shunt pole and a ground.

25. A method according to claim 19, wherein the tuning circuit includes a first tank circuit in series with a second tank circuit, the first tank circuit includes an inductor in series with a first capacitor, the second tank circuit includes an inductor in series with a second capacitor, and the tuning means further includes a tank circuit in series between a capacitor shunt pole and a ground.

26. A method according to claim 19, wherein the tuning circuit includes a first tank circuit in series with a second tank circuit, the first tank circuit includes an inductor in series with a first capacitor, the second tank circuit includes an inductor in series with a second capacitor, and the tuning means further includes a tank circuit in series between all capacitor shunt poles and a ground.