Apparatus and methods for radar imaging based on injected push-push oscillators

• US 7,800,453 B2
• Filed: 09/06/2006
• Issued: 09/21/2010
• Est. Priority Date: 11/07/2005
• Status: Active Grant

• Current Assignee: Beam Semiconductor Ltd.
• Original Assignee: Beam Networks Ltd.
• Inventors: Milano, Alberto
• Primary Examiner(s): Tarcza; Thomas H
• Assistant Examiner(s): Brainard; Timothy A
• Application Number:
  US12/092,579
• Publication Number:
  US 20080278369A1
• Time in Patent Office: 1,476 Days
• Field of Search: 342/175
• US Class Current: 331/34
• CPC Class Codes: G01S 13/89 for mapping or imaging
• CPC Class Codes: G01S 2013/0254 Active array antenna
• CPC Class Codes: G01S 7/032 Constructional details for solid-state radar subsystems
• CPC Class Codes: G01S 7/282 Transmitters
• CPC Class Codes: H01Q 1/3233 particular used as part of a sensor or in a security system, e.g. for automotive radar, navigation systems
• CPC Class Codes: H01Q 3/26 varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture H01Q3/12, H01Q3/22, H01Q3/24 take precedence

Abstract

The present invention relates to radar imaging and to phased array antennas. The invention also relates to transmitter/receiver modules, push-push oscillators and Injection locked push-push oscillators for phased array antennas. The invention reduces the production cost and improves the performance of conventional phased array antennas.

Claims

1. A reference signal generator comprising:

a quartz oscillator; and

at least one level of phase shifted injection locked push-push oscillators cascaded with the quartz oscillator;

wherein said phase shifted injection locked push push oscillators comprise one or more push push oscillators and are adapted to receive an injected signal of a specific frequency and phase, and produce a signal with a frequency that is an even integer multiple of the input frequency and with a phase shift relative to the injected signal.

2. A reference signal generator according to claim 1 wherein the reference signal generator comprises only two levels of phase shifted injection locked push-push oscillators.

3. A reference signal generator according to claim 1 wherein the reference signal generator comprises at least first and second levels of phase shifted injection locked push-push oscillators.

4. A reference signal generator according to claim 3 wherein at least one individual level of push-push oscillators comprises more than one phase shifted injection locked push-push oscillator.

5. A reference signal generator according to claim 1, further comprising multiple phase shifted injection locked push-push oscillators forming a tree structure.

10. Radar imaging apparatus comprising:

a reference signal generator according to claim 1;

a phased array antenna including at least one transmitter/receiver module with phase shifted injection locked push-push oscillators; and

additional apparatus cascaded with the reference signal generator and with at least one transmitter/receiver module to generate a radar image.

11. Imaging radar apparatus according to claim 10 wherein said transmitter receiver module comprises at least one level of phase shifted injection locked push-push oscillators.

6. A transmitter/receiver module comprising:

at least one level of phase shifted injection locked push-push oscillators; and

a receiving functionality receiving a sampled portion of power subsequently radiated by the transmitter/receiver with phase shifted injection locked push-push oscillators;

wherein said phase shifted injection locked push push oscillators comprise one or more push push oscillators and are adapted to receive an injected signal of a specific frequency and phase, and produce a signal with a frequency that is an even integer multiple of the input frequency and with a phase shift relative to the injected signal.

7. A transmitter/receiver module according to claim 6 wherein said transmitter/receiver module comprises a plurality of levels of phase shifted injection locked push-push oscillators.

8. A transmitter/receiver module according to claim 6 wherein said receiving functionality comprises a direct balanced down converter.

9. A transmitter/receiver module according to claim 6, further comprising multiple phase shifted injection locked push-push oscillators forming a tree structure.

12. Imaging radar apparatus comprising:

a reference signal generator;

at least one transmitter/receiver module according to claim 6; and

additional apparatus cascaded with the reference signal generator and with at least one transmitter/receiver module to generate a radar image.

13. A method for generating a reference signal for radar imaging, the method comprising:

cascading a quartz oscillator with at least one level of phase shifted injection locked push-push oscillators

wherein said phase shifted injection locked push push oscillators comprise one or more push push oscillators and are adapted to receive an injected signal of a specific frequency and phase, and produce a signal with a frequency that is an even integer multiple of the input frequency and with a phase shift relative to the injected signal.

14. A method according to claim 13 wherein said quartz oscillator is cascaded with a plurality of levels of phase shifted injection locked push-push oscillators.

15. A method according to claim 13 wherein said at least one level of phase shifted injection locked push-push oscillators comprises only two levels of phase shifted injection locked push-push oscillators.

16. A method according to claim 13 wherein at least one individual level of phase shifted injection locked push-push oscillators comprises more than one phase shifted injection locked push-push oscillators.

17. A method for generating a radar transmitter/receiver module of a phased array antenna comprising:

providing at least one level of phase shifted injection locked push-push oscillators and a receiving functionality receiving a sampled portion of power subsequently radiated by the phase shifted injection locked push-push oscillators; and

wherein said phase shifted injection locked push push oscillators comprise one or more push push oscillators and are adapted to receive an injected signal of a specific frequency and phase, and produce a signal with a frequency that is an even integer multiple of the input frequency and with a phase shift relative to the injected signal.

18. A method according to claim 17 and further comprising cascading a reference signal generator and additional apparatus with said at least one level of phase shifted injection locked push-push oscillators to generate a radar image.

19. A radar imaging method comprising cascading a reference signal generator comprising at least one level of phase shifted injection locked push-push oscillators, a phased array antenna comprising at least one transmitter/receiver module, and additional apparatus to generate a radar image;

and

wherein said phase shifted injection locked push push oscillators comprise one or more push push oscillators and are adapted to receive an injected signal of a specific frequency and phase, and produce a signal with a frequency that is an even integer multiple of the input frequency and with a phase shift relative to the injected signal.

20. A method according to claim 19 wherein said transmitter receiver module comprises at least one level of phase shifted injection locked push-push oscillators.

21. A radar imaging method according to claim 19, further comprising:

at least first and second levels of phase shifted injection locked push-push oscillators.

22. A radar imaging method according to claim 19, further comprising:

using a cascade comprising a reference signal generator, a phased array antenna comprising at least one transmitter/receiver module comprising at least one level of phase shifted injection locked push-push oscillators, and radiating apparatus to generate a radar image.

23. A radar imaging method according to claim 19, wherein said reference signal generator comprises a quartz oscillator.