RADAR SYSTEM COMPRISING A SWITCHING MODE POWER CONVERTER

• US 20120105273A1
• Filed: 07/01/2009
• Published: 05/03/2012
• Est. Priority Date: 07/01/2009
• Status: Active Grant

• Current Assignee: Saab AB
• Original Assignee: Saab AB
• Inventors: Nettelblad, Bo
• Granted Patent: US 9,013,346 B2
• Time in Patent Office: Days
• US Class Current: 342/201
• CPC Class Codes: G01S 7/282 Transmitters
• CPC Class Codes: H02M 1/44 Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators

Abstract

A radar system including a switching mode power converter. A pulse radar unit is configured to transmit RF pulses with a pulse repetition frequency. The power converter includes a switching controller that is configured to control at least one switching element. The switching controller is configured to receive a frequency modulated input signal. The modulation frequency of the input signal is configured to be derived from the pulse repetition frequency of the radar unit.

Claims

1. A radar system, comprising:

a switching mode power converter, and

a pulse radar unit configured to transmit RF pulses with a pulse repetition frequency, and

wherein the power converter comprises a switching controller, which is configured to control at least one switching element, wherein the switching controller is configured to receive a frequency modulated input signal, such that generated and conducted EMI from the power converter is spread over a frequency interval, and wherein the modulation frequency of said input signal is configured to be derived from the pulse repetition frequency of the radar unit.

2. The radar system according to claim 1, wherein a pulse repetition frequency signal carrying the pulse repetition frequency of the radar unit is configured to be supplied from the radar unit to the power converter.

3. The radar system according to claim 1, wherein a signal carrying the pulse repetition frequency, or an integer multiple thereof, is supplied to a frequency modulator, which is configured to generate the frequency modulated input signal.

4. The radar system according to claim 1, wherein the pulse repetition frequency signal is supplied to a first waveform generator, which is configured to generate a modulating signal having a modulating frequency derived from said pulse repetition frequency, and wherein a second waveform generator is configured to generate a base switching signal having a center frequency, and wherein the base switching signal and the modulating signal are supplied to a frequency modulator, which is configured to generate a frequency modulated input signal having a center frequency from the base switching signal and a modulation frequency from the modulating signal.

5. The radar system according to claim 4, wherein the relationship between the modulating frequency and the center frequency, which determines the spread of the switching frequency bands, is between 3-15%.

6. The radar system according to claim 1, wherein the frequency of the pulse repetition frequency signal is configured to be multiplied with an integer n in a frequency multiplier before being supplied to a frequency modulator.

7. The radar system according to claim 1, wherein the frequency of the pulse repetition frequency signal is configured to be multiplied with an integer n in a frequency multiplier before or after being supplied to a waveform generator, such as to generate a modulating signal having a modulating frequency which is an integer multiple of the pulse repetition frequency.

8. The radar system according to claim 1, wherein the switching controller is a pulse width modulator.

9. A method of reducing noise picked-up by a radar unit and generated by a switching mode power converter, whereby the radar unit transmits RF pulses with a pulse repetition frequency, the method comprising:

controlling at least one switching element with a switching controller; and

supplying a frequency modulated input signal to the switching controller, such that generated and conducted EMI from the power converter is spread over a frequency interval,

wherein the modulation frequency of said input signal is derived from the pulse repetition frequency of the radar unit.

10. The method according to claim 9, further comprising:

supplying a pulse repetition frequency signal carrying the pulse repetition frequency of the radar unit from the radar unit to the power converter.

11. The method according to claim 9, further comprising:

supplying the pulse repetition frequency of the radar unit, or an integer multiple thereof, to a frequency modulator, which generates the frequency modulated input signal.

12. The method according to claim 9, further comprising:

supplying the pulse repetition frequency signal to a first waveform generator, which generates a modulating signal having a modulating frequency derived from said pulse repetition frequency;

generating a base switching signal having a center frequency in a second waveform generator; and

supplying the base switching signal and the modulating signal to a frequency modulator, which generates a frequency modulated input signal having a center frequency from the base switching signal and a modulation frequency from the modulating signal.

13. The method according to claim 12, wherein the relationship between the modulating frequency and the center frequency, which determines the spread of the switching frequency bands, is between 3-15%.

14. The method according to claim 9, further comprising:

multiplying the frequency of the pulse repetition frequency signal with an integer n in a frequency multiplier before supplying said pulse repetition frequency signal to a frequency modulator.

15. The method according to claim 9, further comprising:

multiplying the frequency of the pulse repetition frequency signal with an integer n in a frequency multiplier before or after supplying said pulse repetition frequency signal to a waveform generator, such as to generate a modulating signal having a modulating frequency which is an integer multiple of the pulse repetition frequency.