Frequency-Independent Receiver and Beamforming Technique

• US 20180083813A1
• Filed: 09/19/2017
• Published: 03/22/2018
• Est. Priority Date: 09/20/2016
• Status: Active Grant

• Current Assignee: Ohio State Innovation Foundation (Ohio State University)
• Original Assignee: Ohio State Innovation Foundation (Ohio State University)
• Inventors: Novak, Markus H., Venkatakrishnan, Satheesh Bojja, Volakis, John L.
• Granted Patent: US 10,439,851 B2
• Time in Patent Office: Days
• CPC Class Codes: H01Q 3/42 using frequency-mixing H01Q3/2676 takes precedence
• CPC Class Codes: H04B 1/38 Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0837 using pre-detection combining H04B7/0868 takes precedence
• CPC Class Codes: H04B 7/084 Equal gain combining, only phase adjustments antenna beam scanning or forming by phase or amplitude control H01Q3/26, e.g. phased arrays
• CPC Class Codes: H04L 27/14 Demodulator circuits; Receiver circuits

Abstract

Example systems and methods described herein relate to radio communication architectures and techniques for beamforming and down-conversion without a priori knowledge of the source location or frequency. An example radio receiver includes a plurality of antenna elements that include a first element, a second element, and a third element. The radio receiver also includes a plurality of mixers coupled to the plurality of antenna elements and a combiner coupled to the plurality of antenna elements. A signal incident on the first element is mixed with itself via a first mixer of the plurality of mixers. An output of the first mixer is mixed with a signal incident on the second element via a second mixer of the plurality of mixers, and an output of the second mixer is combined via the combiner with a signal incident on the third element.

Claims

1. A radio receiver comprising:

a plurality of antenna elements, the plurality of antenna elements comprising a first antenna element, a second antenna element, and a third antenna element;

a plurality of mixers coupled to the plurality of antenna elements; and

a combiner coupled to the plurality of antenna elements, wherein the plurality of antenna elements, the plurality of mixers, and the combiner are arranged such that a signal incident on the first antenna element would be mixed with itself via a first mixer of the plurality of mixers, wherein an output of the first mixer is mixed with a signal incident on the second antenna element via a second mixer of the plurality of mixers, wherein an output of the second mixer is combined via the combiner with a signal incident on the third antenna element.

2. The radio receiver of claim 1, further comprising:

a plurality of mixers coupled to an output of the combiner, the plurality of mixers being arranged such that a signal at the output of the combiner would be mixed with a second signal having a particular frequency, the output of which is further mixed with the signal at the output of the combiner.

3. The radio receiver of claim 2, wherein the signal at the output of the combiner is modulated with a carrier frequency, and wherein the second signal has a frequency other than the carrier frequency.

4. The radio receiver of claim 2, wherein the second signal is a DC signal.

5. A radio receiver comprising:

an input;

a first output; and

a plurality of mixers arranged such that a received signal at the input of the radio receiver would be mixed with a second signal having a particular frequency, wherein an output of the plurality of mixers is further mixed with the received signal and projected at the first output of the radio receiver.

6. The radio receiver of claim 5, wherein the received signal is modulated with a carrier frequency, wherein the the particular frequency is different from the carrier frequency.

7. The radio receiver of claim 5, wherein the second signal is a DC signal.

8. The radio receiver of claim 5, further comprising:

a second output, wherein the plurality of mixers are further arranged such that the received signal at the input of the radio receiver would be mixed with a second signal having a particular frequency, wherein a second output of the plurality of mixers is further mixed with the received signal and projected at the second output of the radio receiver.

9. A demodulation method comprising:

receiving, at a radio receiver, an input signal;

mixing, at a mixer, the input signal with itself, thereby obtaining a squared input signal;

converting the squared input signal to a digital input signal, the digital input signal comprising a series of bits;

suppressing alternate bits of the digital input signal beginning with a second bit of the series of bits of the digital input signal, thereby obtaining a differential digital input signal; and

translating, with a translation circuit, the differential digital input signal to the input signal by detecting transitions in the series of bits of the differential digital input signal and outputting a translated signal that corresponds to the detected transitions, the translated signal being substantially similar to the input signal.

10. The demodulation method of claim 9, wherein the input signal is modulated with a carrier frequency.

11. The demodulation method of claim 9, wherein the translation circuit comprises:

a D flip-flop, having an input and an output; and

an exclusive-NOR gate having a first input, a second input, and an output, wherein the output of the exclusive-NOR gate is coupled to the input of the D flip-flop, wherein the second input of the exclusive-NOR gate is coupled to the output of the D flip-flop.

12. An antenna array comprising:

a plurality of antenna elements arranged in a matrix, the matrix having a number of columns and a number of rows, wherein each antenna element of the plurality of antenna elements exists at a position within the matrix at an intersection of a column and a row and wherein each antenna element of the plurality of antenna elements comprises a mixer configured to produce a phased superposition mix of a first signal and a second signal;

a first set of phase shifters, each phase shifter of the first set of phase shifters being configured to apply a respective phase shift to an input signal; and

a second set of phase shifters, each phase shifter of the second set of phase shifters being configured to apply a respective phase shift to an input signal,

wherein the first set of phase shifters are arranged such that the first signal is applied with a same phase shift to each mixer of each antenna element in a respective row of the matrix, and

wherein the second set of phase shifters are arranged such that the second signal is applied with a same phase shift to each mixer of each antenna element in a respective row of the matrix.

13. The antenna array of claim 12,

wherein the first set of phase shifters comprises a number of phase shifters equal to the number of columns in the matrix, and

wherein the second set of phase shifters comprises a number of phase shifters equal to the number of rows in the matrix.

14. The antenna array of claim 12, wherein each antenna element comprises:

a respective antenna;

an output mixer coupled to the respective antenna and configured to produce a mix between a signal incident at the respective antenna and the phased superposition mix of the first signal and the second signal; and

an input mixer coupled to the respective antenna and configured to produce a mix between a third signal and the phased superposition mix of the first signal and the second signal.

15. The antenna array of claim 14, wherein the third signal is a baseband input signal.

16. A method comprising:

applying a first signal to each antenna element of a plurality of antenna elements, the plurality of antenna elements being arranged in a matrix, the matrix having a number of columns and a number of rows, wherein each antenna element of the plurality of antenna elements exists at a position within the matrix at an intersection of a column and a row; and

applying a second signal to each antenna element of the plurality of antenna elements;

shifting a phase of the first signal such that for each application of the first signal to mixers positioned in a given column of the matrix, the first signal is applied with a same phase shift;

shifting a phase of the second signal such that for each application of the second signal to mixers positioned in a respective row of the matrix, the second signal is applied with a same phase shift; and

at each respective antenna element of the plurality of antenna elements, mixing the phase-shifted first signal applied to the respective antenna element with the phase-shifted second signal applied to the respective antenna element.

17. The method of claim 16, wherein the step of shifting the phase of the first signal such that for each application of the first signal to mixers positioned in a respective column of the matrix, the first signal is applied with the same phase shift comprises:

shifting the phase of the first signal using a number of phase shifters equal to the number of columns in the matrix.

18. The method of claim 16, wherein the step of shifting the phase of the second signal such that for each application of the second signal to mixers positioned in a respective row of the matrix, the second signal is applied with the same phase shift comprises:

shifting the phase of the second signal using a number of phase shifters equal to the number of rows in the matrix.

19. The method of claim 16, wherein each antenna element comprises:

a respective antenna;

an output mixer coupled to the respective antenna and configured to produce a mix between a signal incident at the respective antenna and a phased superposition mix of the first signal and the second signal; and

an input mixer coupled to the given antenna and configured to produce a mix between a third signal and the phased superposition mix of the first signal and the second signal.

20. The method of claim 19, wherein the third signal is a baseband input signal.