Broadband radar and modulator, in particular for microwave switching over a very short period

• US 20040061640A1
• Filed: 06/10/2003
• Published: 04/01/2004
• Est. Priority Date: 12/15/2000
• Status: Active Grant

• Current Assignee: Beijing Voyager Technology Co., Ltd.
• Original Assignee: Thales SA
• Inventors: Cornic, Pascal, Liabeuf, Bernard, Laviec, Philippe, Melero, Francisco
• Granted Patent: US 7,161,526 B2
• Time in Patent Office: Days
• US Class Current: 342/70
• CPC Class Codes: G01S 13/0209 Systems with very large relative bandwidth, i.e. larger than 10 %, e.g. baseband, pulse, carrier-free, ultrawideband
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/9314 Parking operations
• CPC Class Codes: G01S 7/282 Transmitters

Abstract

The present invention relates to an ultrawideband radar. It also relates to a modulator, in particular for switching microwaves over a very short duration.

The radar includes a modulator modulating a carrier microwave, this modulator including:

a microwave mixer (21)

means for generating a modulation signal (23).

The microwave enters on one input of the mixer and the modulation signal (22) on the other input of the mixer, the output signal from the mixer being provided to the transmission means of the radar.

Advantageously, the modulation signal may be pulsed and of very short duration. A local oscillator (1), operating as a free oscillator, provides the microwave to be modulated.

The invention applies in particular in respect of aiding the parking of motor vehicles. More generally, it applies in respect of all applications which require low-cost high distance resolution radar detection.

Claims

1. A radar comprising a modulator modulating a carrier microwave, this modulator including:

a microwave mixer (21);

means (23) for generating a modulation signal (22);

the microwave entering on one input of the mixer (21) and the modulation signal (22) entering on the other input of the mixer, the output signal from the mixer being provided to the transmission means (25, 3) of the radar.

2. The radar as claimed in claim 1, characterized in that the modulation signal (22) is pulsed.

3. The radar as claimed in any one of the preceding claims, characterized in that it comprises a local oscillator (1), operating as a free oscillator, providing the microwave to be modulated.

4. The radar as claimed in any one of the preceding claims, characterized in that a transmit antenna (3) is linked to the output of the mixer (21).

5. The radar as claimed in claim 4, characterized in that the antenna (3) is linked to the mixer (21) via amplifying means (25).

6. The radar as claimed in any one of the preceding claims, characterized in that it comprises a receive antenna (5) linked to the input of at least one microwave mixer (6, 61, 62) whose other input receives the carrier wave, the demodulated signal obtained at the output of the mixer being intended for the processing circuits (23, 72, 73, 74).

7. The radar as claimed in claim 6, characterized in that it comprises a dual mixer at reception (61, 62), a circuit (63) placed on the input path of one of the two mixers phase shifting the carrier wave (1) by π

/2.

8. The radar as claimed in any one of the preceding claims, characterized in that the means (23) for generating a modulation signal provide several pulses per recurrence period.

9. The radar as claimed in claim 8, characterized in that the means (23) provide a pseudo-random code.

10. The radar as claimed in claim 9, characterized in that the means (23) provide a code taking the values −

1 or +1.

11. The radar as claimed in any one of claims 8 to 10, characterized in that the code is a polynomial whose periodicity is greater than the outward/return propagation time to a target of maximum range.

12. The radar as claimed in any one of the preceding claims, characterized in that the means (23) for generating the pulses are a digital circuit moreover comprising the reception signals processing circuits (71, 72, 73, 74).

13. The radar as claimed in any one of the preceding claims, characterized in that it processes the distance bins in a periodic manner.

14. The radar as claimed in any one of the preceding claims, characterized in that the antennas (3, 5) each consist of an array of patches.

15. A microwave modulator, characterized in that it includes at least:

a microwave mixer (21);

means (23) for generating a modulation signal (22);

the wave to be modulated entering in one input of the mixer, the modulation signal (22) entering on the other input of the mixer, the modulated signal being provided at the output of the mixer.

16. The modulator as claimed in claim 15, characterized in that the modulation signal is pulsed.

17. The modulator as claimed in either of claims 15 or 16, characterized in that it includes means of opto-electronic coupling for modulating an optical wave.