Circuits and methods for antenna-based self-interference cancellation

• US 10,090,585 B2
• Filed: 08/23/2016
• Issued: 10/02/2018
• Est. Priority Date: 08/23/2015
• Status: Active Grant

• Current Assignee: Trustees Of Columbia University In The City Of New York (Columbia University)
• Original Assignee: Trustees Of Columbia University In The City Of New York (Columbia University)
• Inventors: Dinc, Tolga, Krishnaswamy, Harish
• Primary Examiner(s): Pan, Yuwen
• Assistant Examiner(s): Chen, Zhitong
• Application Number:
  US15/244,869
• Publication Number:
  US 20170054224A1
• Time in Patent Office: 770 Days
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 1/525 between emitting and receiving antennas
• CPC Class Codes: H01Q 21/06 Arrays of individually energised antenna units similarly polarised and spaced apart
• CPC Class Codes: H01Q 5/314 using frequency dependent circuits or components, e.g. trap circuits or capacitors
• CPC Class Codes: H04B 1/06 Receivers
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks

Abstract

Circuits and methods for antenna-based self-interference cancellation are provided. In some embodiments, circuits for antenna-based self-interference cancellation are provided, the circuits comprising: a transmit antenna having a transmit port that receives a transmit signal; a receive antenna having a receive port that is cross-polarized with respect to the transmit port and having an auxiliary port that is co-polarized with respect to the transmit port; and a termination connected to the auxiliary port that reflects a signal received at the auxiliary port as a reflected signal, wherein the reflected signal counters interference caused by the transmit signal at the receive port.

Claims

1. A circuit for antenna-based self-interference cancellation, comprising:

a transmit antenna having a transmit port that receives a transmit signal;

a receive antenna having a receive port that is cross-polarized with respect to the transmit port and having an auxiliary port that is co-polarized with respect to the transmit port; and

a termination connected to the auxiliary port that reflects a signal received at the auxiliary port as a reflected signal, wherein the reflected signal counters interference caused by the transmit signal at the receive port.

2. The circuit of claim 1, wherein the termination is formed from a parallel combination of a resistance, an inductance, and a capacitance.

3. The circuit of claim 2, wherein the inductance is fixed.

4. The circuit of claim 3, wherein the inductance is implemented using a transmission line.

5. The circuit of claim 2, wherein the resistance is implemented using a voltage controlled attenuator.

6. The circuit of claim 2, wherein the capacitance is implemented using a varactor diode.

7. The circuit of claim 1, wherein the transmit port, the receive port, and the auxiliary port each have non-zero feed line length.

8. The circuit of claim 1, wherein a slope of conductance synthesized by the termination over a frequency range is substantially zero.