Device for modulating a microwave signal, transponder including such a device, and responder beacon equipped with such a transponder

Patent metadata

Field	Value
Publication number	US-10879846-B2
Application number	US-201816486284-A
Country	US
Kind code	B2
Filing date	Feb 28, 2018
Priority date	Mar 14, 2017
Publication date	Dec 29, 2020
Grant date	Dec 29, 2020

Abstract

The modulation includes in amplifying the microwave signal phase shifted by a given angle into a first sinusoidal signal, in order to obtain a first amplified signal; and in amplifying the microwave signal phase shifted by the given angle increased by π into a second sinusoidal signal phase shifted by π with respect to the first signal, in order to obtain a second amplified signal phase shifted by π with respect to the first amplified signal; the modulated microwave signal being the sum of the first amplified signal and the second amplified signal.

First claim

The invention claimed is:

1. A device for modulating a microwave signal, wherein it comprises at least:
a circuit for generating a rectified sinusoidal signal;
a phase-shifting circuit able to receive as input said microwave signal comprising:
a first channel applying a given phase shift;
a second channel applying said given phase shift increased by π;

a variable-gain amplifier the gain of which is controlled by said rectified sinusoidal signal;
a switch controlled by said rectified sinusoidal signal, able to alternatively switch said first channel and said second channel to the input of said amplifier, the switch from one channel to the next being performed on each passage through 0 of said rectified sinusoidal signal, the output signal of said amplifier being the modulated microwave signal.

2. The device as claimed in claim 1 , wherein it comprises:
a second circuit for generating a rectified sinusoidal signal;
a second variable-gain amplifier the gain of which is controlled by said rectified sinusoidal signal generated by said second circuit;
a second switch controlled by said rectified sinusoidal signal, able to alternatively switch said first channel and said second channel to the input of said second amplifier, the switch from one channel to the next being performed on each passage through 0 of said rectified sinusoidal signal;
an adder that sums the signal output from said first amplifier and the signal output from said second amplifier;
the signal output from said adder, resulting from the summation of said output signals, being the modulated signal.

3. The device as claimed in claim 2 , wherein it comprises a phase-shifter between said second switch and said second variable-gain amplifier, said phase-shifter applying a phase shift of +π/2, said modulated signal being single-sideband modulated.

4. The device as claimed in claim 1 , wherein said given phase shift is zero.

5. The device as claimed in claim 4 , wherein said first channel connects the input of said phase-shifting circuit to a first input of said switch, said second channel comprising a phase-shifter that applies a phase shift of π and that is connected between said input and a second input of said switch.

6. The device as claimed in claim 1 , wherein said given phase shift is equal to −π/2.

7. The device as claimed in claim 6 , wherein:
said first channel comprises a first phase-shifter that applies a phase shift of −π/2 and that is connected between the input of said phase-shifting circuit and a first input of said switch;
said second channel comprises a second phase-shifter that applies a phase shift of +π/2 and that is connected between said input and a second input of said switch.

8. A transponder, wherein it comprises at least:
receiving means able to receive a microwave signal;
a modulating device as claimed in claim 1 , that modulates the signal output from said receiving circuit;
emitting means that are able to emit the modulated signal output from said modulating device.

9. The transponder as claimed in claim 8 , wherein said receiving means comprising an antenna composed of an array of radiating elements, said phase shift of π between said first channel and said second channel is obtained in the radiating elements between the positive polarity and the negative polarity of each radiating element, the first channel being connected to all of the positive polarities and the second channel being connected to all of the negative polarities.

10. A responder beacon, wherein it is equipped with a transponder as claimed in claim 8 .

11. The responder beacon as claimed in claim 10 , wherein said rectified sinusoid or said sinusoidal signals are substantially at the frequency of 1 kHz.

12. A device for modulating a microwave signal wherein it comprises at least:
a circuit for generating a first sinusoidal signal and a second sinusoidal signal that is phase shifted by π with respect to said first signal;
a first channel, able to receive as input said microwave frequency signal, comprising a first phase-shifter that applies a given phase shift and a first variable-gain amplifier the gain of which is controlled by said first sinusoidal signal;
a second channel, able to receive as input said microwave frequency signal, comprising a second phase-shifter that applies said given phase shift increased by π and a second variable-gain amplifier the gain of which is controlled by said second sinusoidal signal;
an adder that sums the signal output from said first amplifier and the signal output from said second amplifier;

the signal output from said adder, resulting from the summation of said output signals, being the modulated signal.

13. The device as claimed in claim 12 , wherein said given phase shift is zero.

14. The device as claimed in claim 12 , wherein said given phase shift is equal to −π/2.

15. The device as claimed in claim 12 , wherein said generating circuit comprises at least a low-frequency generator that delivers said sinusoidal signal and a circuit containing a differential amplifier that, on the one hand, reproduces said sinusoidal signal in order to form said first sinusoidal signal and that, on the other hand, delivers a sinusoidal signal that is phase-shifted by π with respect to said sinusoidal signal in order to form said second sinusoidal signal.

Assignees

• Thales Sa

Inventors

• Garrec Patrick
• Despoisse Thibaut
• Ghiotto Anthony

Classifications

• H04B14/004 Primary

  Amplitude modulation · CPC title

• H03C5/02 Primary

  by means of transit-time tube · CPC title

• H03C5/00

  Amplitude modulation and angle modulation produced simultaneously or at will by the same modulating signal (H03C7/00 takes precedence) · CPC title

• G01S13/82

  wherein continuous-type signals are transmitted · CPC title

• G01S13/756

  using a signal generator for modifying the reflectivity of the reflector (G01S13/758 takes precedence) · CPC title