Magnetless non-reciprocal devices using modulated filters

Patent metadata

Field	Value
Publication number	US-10804583-B2
Application number	US-201716332077-A
Country	US
Kind code	B2
Filing date	Sep 13, 2017
Priority date	Sep 16, 2016
Publication date	Oct 13, 2020
Grant date	Oct 13, 2020

Abstract

A magnet-free non-reciprocal device realized using modulated filters. The device includes one or more filters in one or more branches, where each branch connects two ports or a port and a central node. The poles and zeros of each of the first, second and third filters are modulated in time such that degenerate modes at each pole and zero is split thereby destructively interfering at one or more output ports and adding up at another output port allowing non-reciprocal transmission, isolation and/or non-reciprocal phase shift. The device is able to realize a magnet-free full-duplex communication scheme implementing a magnet-free circulator for radio frequency cancellation or a magnet-free isolator or gyrator.

First claim

The invention claimed is:

1. A magnet-free multiple-port non-reciprocal device, comprising:
one or more filters in one or more branches, wherein each of said one or more branches connects two ports;
wherein poles and zeros of each of said one or more filters are modulated in time such that degenerate modes at each pole and zero are split thereby destructively interfering at one or more output ports and adding up at another output port creating isolation and non-reciprocal operation.

2. The magnet-free multiple-port non-reciprocal device as recited in claim 1 , wherein each of said one or more filters comprises one of the following: a bandpass filter and a bandstop filter.

3. The magnet-free multiple-port non-reciprocal device as recited in claim 1 , wherein one or more of said one or more filters comprise a low pass filter or a high pass filter.

4. The magnet-free multiple-port non-reciprocal device as recited in claim 1 , wherein one or more of said one or more filters can be realized as a delay line.

5. The magnet-free multiple-port non-reciprocal device as recited in claim 1 , wherein one or more of said one or more filters comprise an inductor-less N-path filter.

6. The magnet-free multiple-port non-reciprocal device as recited in claim 1 , wherein one or more of said one or more filters comprise a higher order filter greater than a first-order filter.

7. The magnet-free multiple-port non-reciprocal device as recited in claim 1 , wherein one or more of said one or more filters comprise inductors, capacitors, resistors, switches, transistors, or varactors.

8. The magnet-free multiple-port non-reciprocal device as recited in claim 1 , wherein one or more of said one or more filters are digitally modulated by applying clock signals to switches.

9. The magnet-free multiple-port non-reciprocal device as recited in claim 1 , wherein one or more of said one or more filters are analog modulated by applying modulation signals to varactors.

10. The magnet-free multiple-port non-reciprocal device as recited in claim 1 further comprising:
a first branch between a first port and a second port;
a second branch between said second port and a third port; and
a third branch between said third port and said first port;
wherein a second modulation signal of twice an operation frequency is applied in phase to said first, second and third branches.

11. The magnet-free multiple-port non-reciprocal device as recited in claim 1 further comprising:
a matching network at an input port and output ports.

12. The magnet-free multiple-port non-reciprocal device as recited in claim 1 further comprising:
a first branch between a first port and a second port;
a second branch between said second port and a third port; and
a third branch between said third port and said first port;
wherein modulation is applied asymmetrically to one or more of said first, second and third branches.

13. The magnet-free multiple-port non-reciprocal device as recited in claim 1 , wherein an input signal from a first port is transmitted to a second port but not in an opposite direction.

14. The magnet-free multiple-port non-reciprocal device as recited in claim 1 , wherein one or more of said one or more filters are differential or balanced filters, wherein modulation is applied differentially to said one or more of said one or more filters.

15. The magnet-free multiple-port non-reciprocal device as recited in claim 14 further comprising:
a balun at an input port and output ports.

16. The magnet-free multiple-port non-reciprocal device as recited in claim 1 , wherein a first port is connected to a transmitter, a second port is connected to an antenna and a third port is connected to a receiver, wherein said transmitter and receiver are allowed to operate simultaneously and at a same frequency.

17. The magnet-free multiple-port non-reciprocal device as recited in claim 16 , wherein an input signal from said first, second and third ports are transmitted to said second, third and first ports, respectively, but not in an opposite direction.

18. A magnet-free multiple-port differential non-reciprocal device, comprising:
a first single-ended non-reciprocal device as recited in claim 1 ; and
a second single-ended non-reciprocal device as recited in claim 1 ;
wherein said first and second single-ended non-reciprocal devices are fed with a common source and an output is sensed with a common load, wherein said first and second single-ended non-reciprocal devices have a 180° phase difference between their modulation signals.

19. The magnet-free multiple-port differential non-reciprocal device as recited in claim 18 further comprising:
a matching network at an input port and output ports.

20. A magnet-free multiple-port differential non-reciprocal device, comprising:
a first single-ended non-reciprocal device as recited in claim 1 ; and
a second single-ended non-reciprocal device as recited in claim 1 ;
wherein said first and second single-ended non-reciprocal devices are fed differentially and an output is sensed differentially, wherein said first and second single-ended non-reciprocal devices have a 180° phase difference between their modulation signals.

21. The magnet-free multiple-port differential non-reciprocal device as recited in claim 20 further comprising:
a balun at an input port and output ports.

22. The magnet-free multiple-port non-reciprocal device as recited in claim 20 further comprising:
a matching network at an input port and output ports.

23. A magnet-free multiple-port non-reciprocal device, comprising:
one or more filters in one or more branches, wherein each of said one or more branches connects a port and a central node;
wherein poles and zeros of each of said one or more filters are modulated in time such that degenerate modes at each pole and zero are split thereby destructively interfering at one or more output ports and adding up at another output port creating isolation and non-reciprocal operation.

24. The magnet-free multiple-port non-reciprocal device as recited in claim 23 , wherein each of said one or more filters comprises one of the following: a bandpass filter and a bandstop filter.

25. The magnet-free multiple-port non-reciprocal device as recited in claim 23 , wherein one or more of said one or more filters comprise a low pass filter or a high pass filter.

26. The magnet-free multiple-port non-reciprocal device as recited in claim 23 , wherein one or more of said one or more filters can be realized as a delay line.

27. The magnet-free multiple-port non-reciprocal device as recited in claim 23 , wherein one or more of said one or more filters comprise an inductor-less N-path filter.

28. The magnet-free multiple-port non-reciprocal device as recited in claim 23 , wherein one or more of said one or more filters comprise a higher order filter greater than a first-order filter.

29. The magnet-free multiple-port non-reciprocal device as recited in claim 23 , wherein one or more of said one or more filters comprise inductors, capacitors, resistors, switches, transistors, or varactors.

30. The magnet-free multiple-port non-reciprocal device as recited in claim 23 , wherein one or more of said one or more filters are digitally modulated by applying clock signals to switches.

31. The magn

Assignees

• Univ Texas

Inventors

• Kord Ahmed
• Alu Andrea
• Sounas Dimitrios

Classifications

• H01P1/38

  Circulators · CPC title

• H03H7/52

  One-way transmission networks, i.e. unilines · CPC title

• H03H7/1775 Primary

  Parallel LC in shunt or branch path (H03H7/1791 takes precedence) · CPC title

• H04L5/14

  Two-way operation using the same type of signal, i.e. duplex · CPC title

• H03H7/48

  Networks for connecting several sources or loads, working on the same frequency or frequency band, to a common load or source (phase shifters providing two or more output signals H03H7/21) · CPC title