Tunable filters having variable bandwidth and variable delay

• US 7,034,636 B2
• Filed: 08/05/2004
• Issued: 04/25/2006
• Est. Priority Date: 09/20/2001
• Status: Expired due to Term

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Paratek Microwave Incorporated (Blackberry Limited)
• Inventors: Zhu, Yongfei, Sengupta, Louise, Shamsaifar, Khosro, Kvarnstrand, John
• Primary Examiner(s): TAKAOKA, DEAN O
• Application Number:
  US10/912,284
• Publication Number:
  US 20050007212A1
• Time in Patent Office: 628 Days
• Field of Search: 333/136, 333/139, 333/174, 333/175, 333/179, 333/178, 455/139, 455/234
• US Class Current: 333/174
• CPC Class Codes: H01P 1/20363 Linear resonators
• CPC Class Codes: H03F 1/3229 using a loop for error extraction and another loop for error subtraction
• CPC Class Codes: H03H 7/12 Bandpass or bandstop filters with adjustable bandwidth and fixed centre frequency H03H7/09 takes precedence; automatic control of bandwidth in amplifiers H03G5/16
• CPC Class Codes: H03H 7/1775 Parallel LC in shunt or branch path H03H7/1791 takes precedence

Abstract

An apparatus for reducing influence by selected signal components in a communication link includes a first signal line conveying a first communication signal including a desired signal component and at least one undesired signal component; a second signal line conveying a second communication signal substantially including at least the at least one undesired signal component; a signal treating unit coupled with the second signal line for affecting at least one parameter associated with the second communication signal to present a modified second communication signal at a first output locus coupled for combining the modified second communication signal with the first communication signal to present an improved communication signal at a second output locus. The at least one undesired signal component affects the improved communication signal less than the at least one undesired signal component affects the first communication signal.

Claims

1. An apparatus for reducing influence by selected signal components in a communication link;

the apparatus comprising;

(a) a first signal line coupled with a first signal source;

said first signal line conveying a first communication signal from said first signal source;

said first communication signal including a desired signal component and at least one undesired signal component;

(b) a second signal line coupled with a second signal source;

said second signal line conveying a second communication signal from said second signal source;

said second communication signal substantially including said desired signal component and said at least one undesired signal component;

(c) a signal treating unit coupled with said second signal line;

said signal treating unit affecting at least one parameter associated with said second communication signal to present a modified second communication signal at a first output locus;

said signal treating unit including a tunable bandwidth filter including at least one electronically tunable varactor unit; and

(d) a signal coupling unit coupled with said first signal line and coupled with said first output locus;

said signal coupling unit combining said first communication signal with said modified second communication signal to present an improved communication signal at a second output locus;

said at least one undesired signal component affecting said improved communication signal less than said at least one undesired signal component affects said first communication signal.

2. An apparatus for reducing influence by selected signal components in a communication link as recited in claim 1 wherein said first signal source is an electromagnetic signal receiving antenna, and wherein said second signal source is an electromagnetic signal receiving antenna.

3. An apparatus for reducing influence by selected signal components in a communication link as recited in claim 1 wherein said signal treating unit is a tunable delay line tuned to affect said at least one parameter appropriately to affect said combining to substantially minimize presence of said at least one undesired signal component in said improved communication signal.

4. An apparatus for reducing influence by selected signal components in a communication link as recited in claim 2 wherein said signal treating unit is a tunable delay line tuned to affect said at least one parameter appropriately to affect said combining to substantially minimize presence of said at least one undesired signal component in said improved communication signal.

5. An apparatus for reducing influence by selected signal components in a communication link as recited in claim 1 or 2 or 4 wherein said signal treating unit is a tunable bandwidth filter having a substantially fixed frequency comprising:

(a) an input locus for receiving input signals to the filter;

said input locus being coupled with said second signal line and with at least one conductive member;

said first output locus being coupled with said at least one conductive member;

(b) a plurality of fixed resonator units;

said plurality of resonator units being coupled with said at least one conductive member; and

(c) at least one tunable dielectric varactor unit;

each respective tunable dielectric varactor unit of said at least one tunable dielectric varactor unit being coupled with said at least one conductive member at a respective intermediate locus;

each said respective intermediate locus being situated between a respective pair of said plurality of resonator units;

each respective tunable dielectric varactor unit of said at least one tunable dielectric varactor unit comprising a substrate, a layer of voltage tunable dielectric material established in a first area on said substrate, a first electrode structure for receiving an electrical signal established in a second area on said first area, and a second electrode structure for receiving an electrical signal established in a third area on said first area;

said second area and said third area being separated by a gap;

said voltage tunable dielectric material being a paraelectric material having an operating temperature greater than its Curie temperature.

6. An apparatus for reducing influence by selected signal components in a communication link as recited in claim 1 or 2 wherein said signal treating unit is a tunable phase shifting unit tuned to affect said at least one parameter appropriately to affect said combining to substantially minimize presence of said at least one undesired signal component in said improved communication signal.

7. An apparatus for reducing influence by selected signal components in a communication link as recited in claim 6 wherein said tunable phase shifting unit is a tunable bandwidth filter having a substantially fixed frequency comprising:

(a) an input locus for receiving input signals to the filter;

said input locus being coupled with said second signal line and with at least one conductive member;

said first output locus being coupled with said at least one conductive member;

(b) a plurality of fixed resonator units;

said plurality of resonator units being coupled with said at least one conductive member; and

(c) at least one tunable dielectric varactor unit;

each respective tunable dielectric varactor unit of said at least one tunable dielectric varactor unit being coupled with said at least one conductive member at a respective intermediate locus;

each said respective intermediate locus being situated between a respective pair of said plurality of resonator units;

each respective tunable dielectric varactor unit of said at least one tunable dielectric varactor unit comprising a substrate, a layer of voltage tunable dielectric material established in a first area on said substrate, a first electrode structure for receiving an electrical signal established in a second area on said first area, and a second electrode structure for receiving an electrical signal established in a third area on said first area;

said second area and said third area being separated by a gap;

said voltage tunable dielectric material being a paraelectric material having an operating temperature greater than its Curie temperature.

8. An apparatus for reducing influence by selected signal components in a communication link;

the apparatus comprising;

(a) a receiving signal line coupled with a signal source;

said receiving signal line conveying a communication signal from said signal source;

said communication signal including a desired signal component and at least one undesired signal component;

(b) a signal coupling unit coupled with said receiving signal line;

said signal coupling unit providing a feedback signal at a feedback locus;

said feedback signal being a portion of said communication signal;

said signal coupling unit providing an output signal at an output locus;

said output signal being related with said communication signal;

(c) a signal treating unit coupled with said feedback locus;

said signal treating unit affecting at least one parameter associated with said feedback signal to present a modified feedback signal to said receiving signal line;

said modified feedback signal affecting said communication signal to reduce said at least one undesired signal component in said output signal;

said signal treating unit including a tunable bandwidth filter including at least one electronically tunable varactor unit.

9. An apparatus for reducing influence by selected signal components in a communication link as recited in claim 8 wherein said signal treating unit is a tunable delay line tuned to affect said modified feedback signal appropriately to substantially minimize presence of said at least one undesired signal component in said output signal.

10. An apparatus for reducing influence by selected signal components in a communication link as recited in claim 8 or 9 wherein said signal treating unit is a tunable bandwidth filter having a substantially fixed frequency comprising:

(a) an input locus for receiving input signals to the filter;

said input locus being coupled with said feedback locus and with at least one conductive member;

said output locus being coupled with said at least one conductive member;

(b) a plurality of fixed resonator units;

said plurality of resonator units being coupled with said at least one conductive member; and

(c) at least one tunable dielectric varactor unit;

each respective tunable dielectric varactor unit of said at least one tunable dielectric varactor unit being coupled with said at least one conductive member at a respective intermediate locus;

each said respective intermediate locus being situated between a respective pair of said plurality of resonator units;

each respective tunable dielectric varactor unit of said at least one tunable dielectric varactor unit comprising a substrate, a layer of voltage tunable dielectric material established in a first area on said substrate, a first electrode structure for receiving an electrical signal established in a second area on said first area, and a second electrode structure for receiving an electrical signal established in a third area on said first area;

said second area and said third area being separated by a gap;

said voltage tunable dielectric material being a paraelectric material having an operating temperature greater than its Curie temperature.

11. An apparatus for reducing influence by selected signal components in a communication link as recited in claim 10 wherein said signal treating unit includes a signal amplitude adjusting unit;

said signal amplitude adjusting unit adjusting amplitude of said modified feedback signal to substantially match amplitude of said communication signal.

12. An apparatus for reducing influence by selected signal components in a communication link as recited in claim 8 wherein said signal treating unit is operates as a tunable phase shifting unit tuned to affect said modified feedback signal appropriately to substantially minimize presence of said at least one undesired signal component in said output signal.

13. An apparatus for reducing influence by selected signal components in a communication link as recited in claim 8 or 12 wherein said signal treating unit is a tunable bandwidth filter having a substantially fixed frequency comprising:

(a) an input locus for receiving input signals to the filter;

said input locus being coupled with said feedback locus and with at least one conductive member;

said output locus being coupled with said at least one conductive member;

(b) a plurality of fixed resonator units;

said plurality of resonator units being coupled with said at least one conductive member; and

(c) at least one tunable dielectric varactor unit;

each respective tunable dielectric varactor unit of said at least one tunable dielectric varactor unit being coupled with said at least one conductive member at a respective intermediate locus;

each said respective intermediate locus being situated between a respective pair of said plurality of resonator units;

each respective tunable dielectric varactor unit of said at least one tunable dielectric varactor unit comprising a substrate, a layer of voltage tunable dielectric material established in a first area on said substrate, a first electrode structure for receiving an electrical signal established in a second area on said first area, and a second electrode structure for receiving an electrical signal established in a third area on said first area;

said second area and said third area being separated by a gap;

said voltage tunable dielectric material being a paraelectric material having an operating temperature greater than its Curie temperature.

14. An apparatus for reducing influence by selected signal components in a communication link as recited in claim 13 wherein said signal treating unit includes a signal amplitude adjusting unit;

said signal amplitude adjusting unit adjusting amplitude of said modified feedback signal to substantially match amplitude of said communication signal.

15. An apparatus for reducing influence by selected signal components in a communication link;

the apparatus comprising;

(a) a first signal line conveying a first communication signal including a desired signal component and at least one undesired signal component;

(b) a second signal line conveying a second communication signal;

said second communication signal substantially including at least said at least one undesired signal component;

(c) a signal treating unit coupled with said second signal line;

said signal treating unit affecting at least one parameter associated with said second communication signal to present a modified second communication signal at a first output locus;

said signal treating unit including a tunable bandwidth filter including at least one electronically tunable varactor unit;

said first output locus being coupled for combining said modified second communication signal with said first communication signal to present an improved communication signal at a second output locus;

said at least one undesired signal component affecting said improved communication signal less than said at least one undesired signal component affects said first communication signal.

16. An apparatus for reducing influence by selected signal components in a communication link as recited in claim 15 wherein said signal treating unit is a tunable delay line tuned to affect said modified second communication signal appropriately to substantially minimize presence of said at least one undesired signal component in said improved communication signal.

17. An apparatus for reducing influence by selected signal components in a communication link as recited in claim 15 or 16 wherein said signal treating unit is a tunable bandwidth filter having a substantially fixed frequency comprising:

(a) an input locus for receiving input signals to the filter;

said input locus being coupled to receive said second communication signal and coupled with at least one conductive member;

said first output locus being coupled with said at least one conductive member;

(b) a plurality of fixed resonator units;

said plurality of resonator units being coupled with said at least one conductive member; and

(c) at least one tunable dielectric varactor unit;

each respective tunable dielectric varactor unit of said at least one tunable dielectric varactor unit being coupled with said at least one conductive member at a respective intermediate locus;

each said respective intermediate locus being situated between a respective pair of said plurality of resonator units;

each respective tunable dielectric varactor unit of said at least one tunable dielectric varactor unit comprising a substrate, a layer of voltage tunable dielectric material established in a first area on said substrate, a first electrode structure for receiving an electrical signal established in a second area on said first area, and a second electrode structure for receiving an electrical signal established in a third area on said first area;

said second area and said third area being separated by a gap;

said voltage tunable dielectric material being a paraelectric material having an operating temperature greater than its Curie temperature.

18. An apparatus for reducing influence by selected signal components in a communication link as recited in claim 17 wherein said signal treating unit includes a signal amplitude adjusting unit;

said signal amplitude adjusting unit adjusting amplitude of said modified second communication signal to substantially match amplitude of said first communication signal.

19. An apparatus for reducing influence by selected signal components in a communication link as recited in claim 15 wherein said signal treating unit operates as a tunable delay line tuned to affect said modified second communication signal appropriately to substantially minimize presence of said at least one undesired signal component in said improved communication signal.

20. An apparatus for reducing influence by selected signal components in a communication link as recited in claim 15 or 19 wherein said signal treating unit is a tunable bandwidth filter having a substantially fixed frequency comprising:

(a) an input locus for receiving input signals to the filter;

said input locus being coupled to receive said second communication signal and coupled with at least one conductive member;

said first output locus being coupled with said at least one conductive member

(b) a plurality of fixed resonator units;

said plurality of resonator units being coupled with said at least one conductive member; and

(c) at least one tunable dielectric varactor unit;

each respective tunable dielectric varactor unit of said at least one tunable dielectric varactor unit being coupled with said at least one conductive member at a respective intermediate locus;

each said respective intermediate locus being situated between a respective pair of said plurality of resonator units;

each respective tunable dielectric varactor unit of said at least one tunable dielectric varactor unit comprising a substrate, a layer of voltage tunable dielectric material established in a first area on said substrate, a first electrode structure for receiving an electrical signal established in a second area on said first area, and a second electrode structure for receiving an electrical signal established in a third area on said first area;

said second area and said third area being separated by a gap;

said voltage tunable dielectric material being a paraelectric material having an operating temperature greater than its Curie temperature.

21. An apparatus for reducing influence by selected signal components in a communication link as recited in claim 20 wherein said signal treating unit includes a signal amplitude adjusting unit;

said signal amplitude adjusting unit adjusting amplitude of said modified second communication signal to substantially match amplitude of said first communication signal.