Distributedly modulated capacitors for non-reciprocal components

Patent metadata

Field	Value
Publication number	US-9413050-B2
Application number	US-201414513888-A
Country	US
Kind code	B2
Filing date	Oct 14, 2014
Priority date	Oct 14, 2013
Publication date	Aug 9, 2016
Grant date	Aug 9, 2016

Abstract

An apparatus and method for realizing non-reciprocal components, such as isolators and circulators, for operation over a broad bandwidth without requiring magnetic components/material which would prevent integrated circuit manufacture utilizing standard processes is presented. In one example, a circulator is described including varactor diodes coupled at each unit cell in a balanced manner between halves of a differential signal path and halves of a differential carrier path. In another example, variable capacitors are coupled at each unit cell between a signal path and ground, and having a tuning input of the variable capacitor receiving a signal from a carrier path.

First claim

What is claimed is:

1. A distributedly modulated capacitor (DMC) apparatus, comprising:
a first transmission line for propagating carrier waves;
a second transmission line for propagating signal waves; and
a plurality of time-varying capacitance elements coupled to said second transmission line for propagating signal waves, and to said first transmission line in which said carrier waves modulate capacitance of these time-varying capacitance elements;
wherein said carrier waves and said signal waves propagate on separate first and second transmission lines which are electrically isolated from one another;
wherein shunt capacitance of both first and second transmission lines is predominantly controlled by said carrier waves; and
wherein a signal traveling in an identical direction as that of said carrier wave is modulated on said carrier, while a signal travelling in an opposing direction is not modulated on said carrier.

2. The apparatus recited in claim 1 , wherein said distributedly modulated capacitor (DMC) apparatus comprises an isolator or a circulator.

3. The apparatus recited in claim 1 , wherein said first and second transmission lines are configured as a series connection of unit cells in which each unit cell has said time-varying capacitance elements coupled to the second transmission line as controlled by signals on said first transmission line.

4. The apparatus recited in claim 1 , wherein said distributedly modulated capacitor (DMC) circulator apparatus is fabricated on single or multi-layer printed circuits without inclusion of magnetic components or material.

5. The apparatus recited in claim 1 , wherein said distributedly modulated capacitor (DMC) circulator apparatus is configured for implementation by integrated circuit integration, without incorporation of any magnetic materials.

6. The apparatus recited in claim 1 , wherein said distributedly modulated capacitor (DMC) circulator apparatus is configured for applications selected from a group of applications, consisting of compact radar systems, miniaturized radios, cellphones, and high performance radio-frequency identification (RFID) readers.

7. The apparatus recited in claim 1 , wherein said time-varying capacitance elements comprise a double balanced configuration of varactor diodes.

8. The apparatus recited in claim 7 , wherein a varactor diode is coupled between each half of a differential line forming said second transmission line, to each half of a differential line forming said first transmission line, so that four varactor diodes are required for each unit cell of said first and second transmission line.

9. The apparatus recited in claim 1 , wherein said time-varying capacitance elements comprise variable capacitors.

10. The apparatus recited in claim 9 , wherein a variable capacitor is coupled between said second transmission line to ground, and said first transmission line is coupled to control the capacitance of each said variable capacitor.

11. A distributedly modulated capacitor (DMC) apparatus, comprising:
a double balanced configuration of varactor diodes operating as time-varying capacitances;
a first differential transmission line for propagating carrier waves; and
a second differential transmission line for propagating signal waves;
wherein said carrier waves and said signal waves propagate on these different first and second differential transmission lines which are electrically isolated from one another;
wherein shunt capacitance of both first and second differential transmission lines is predominantly controlled by the carrier waves; and
wherein a signal traveling in the same direction as that of said carrier wave is modulated on the carrier while a signal travelling in an opposite direction is not modulated on the carrier.

12. The apparatus recited in claim 11 , wherein said distributedly modulated capacitor (DMC) apparatus comprises an isolator or a circulator.

13. The apparatus recited in claim 11 , wherein said double balanced configuration of varactor diodes comprises a varactor diode coupled between each half of said first differential transmission line, to each half of said second differential transmission line, so that four varactor diodes are required for each unit cell of said first and second differential transmission lines.

14. The apparatus recited in claim 11 , wherein said first and second differential transmission lines are configured as a series connection of unit cells in which each unit cell has said varactor diode elements coupled to the second differential transmission line as controlled by signals on said first differential transmission line.

15. The apparatus recited in claim 11 , wherein said distributedly modulated capacitor (DMC) circulator apparatus is fabricated on single or multi-layer printed circuits without inclusion of magnetic components or material.

16. The apparatus recited in claim 11 , wherein said distributedly modulated capacitor (DMC) circulator apparatus is configured for implementation by integrated circuit integration, without incorporating magnetic materials.

17. The apparatus recited in claim 11 , wherein said distributedly modulated capacitor (DMC) circulator apparatus is configured for applications selected from a group of applications, consisting of compact radar systems, miniaturized radios, cellphones, and high performance radio-frequency identification (RFID) readers.

18. A distributedly modulated capacitor (DMC) apparatus, comprising:
a first transmission line for propagating carrier waves;
a second transmission line for propagating signal waves; and
a plurality of variable capacitors coupled from said second transmission line to ground, and having a capacitance control input coupled to said first transmission line, so that said carrier waves modulate capacitance of these variable capacitors;
wherein said carrier waves and said signal waves propagate on separate first and second transmission lines which are electrically isolated from one another;
wherein shunt capacitance of both first and second transmission lines is predominantly controlled by said carrier waves; and
wherein a signal traveling in an identical direction as that of said carrier wave is modulated on said carrier while a signal travelling in an opposing direction is not modulated on said carrier.

19. The apparatus recited in claim 18 , wherein said distributedly modulated capacitor (DMC) apparatus comprises an isolator or a circulator.

20. The apparatus recited in claim 18 , wherein said first and second transmission lines are configured as a series connection of unit cells in which each unit cell has said variable capacitors coupled between said second transmission line and ground, while being controlled in response to a signal received from said first transmission line.

21. The apparatus recited in claim 18 , wherein said distributedly modulated capacitor (DMC) circulator apparatus is fabricated on single or multi-layer printed circuits without inclusion of magnetic components or material.

22. The apparatus recited in claim 18 , wherein said distributedly modulated capacitor (DMC) circulator apparatus is configured for implementation by integrated circuit integration, without inclusion of magnetic materials which are bulky and not readily implemented by integrated circuit process technology.

23. The apparatus recited in claim 18 , wherein said distributedly modulated capacitor (DMC) circulator apparatus is configured for applications as

Assignees

• Univ California

Inventors

• Wang Yuanxun Ethan

Classifications

• H01P1/36 Primary

  Isolators · CPC title

• H01P1/15

  by semiconductor devices · CPC title

• H01P1/387

  Strip line circulators · CPC title