Compact, flexible and integrated millimeter wave radar sensor

• US 5,315,303 A
• Filed: 09/30/1991
• Issued: 05/24/1994
• Est. Priority Date: 09/30/1991
• Status: Expired due to Term

• Current Assignee: TRW Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: TRW Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Shreve, Gregory A., LaCon, Martin M., Im, Catherine L., Tsou, Hsi-Shen E.
• Primary Examiner(s): TUBBESING, THEODORE
• Application Number:
  US07/767,953
• Time in Patent Office: 967 Days
• Field of Search: 342/27, 342/128, 342/200
• US Class Current: 342/27
• CPC Class Codes: G01S 13/345 using triangular modulation
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/0263 Passive array antenna
• CPC Class Codes: G01S 2013/932 using own vehicle data, e.g. ground speed, steering wheel direction
• CPC Class Codes: G01S 2013/9321 Velocity regulation, e.g. cruise control
• CPC Class Codes: G01S 2013/93272 in the back of the vehicles
• CPC Class Codes: G01S 2013/93274 on the side of the vehicles
• CPC Class Codes: G01S 2013/93275 in the bumper area
• CPC Class Codes: G01S 2013/93277 in the lights
• CPC Class Codes: G01S 7/032 Constructional details for solid-state radar subsystems
• CPC Class Codes: G01S 7/2883 using FFT processing
• 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 13/10 Resonant slot antennas
• CPC Class Codes: H01Q 15/0006 Devices acting selectively as reflecting surface, as diffracting or as refracting device, e.g. frequency filtering or angular spatial filtering devices H01Q15/12, H01Q15/22, H01Q15/24 take precedence
• CPC Class Codes: H01Q 21/065 Patch antenna array

Abstract

A compact radar sensor is provided. A monolithic millimeter wave integrated circuit (MMIC) transceiver is provided having a transmitter for transmitting a frequency modulated signal and a receiver for receiving reflected signals thereof. A microstrip patch antenna is provided for transmitting signals within a desired field and receiving the reflected signals from objects therein. A digital signal processor is further provided for analyzing the received signal and providing output signals therefrom.

Claims

1. A compact highly integrated radar system for detecting objects within a desired field, said system comprising:

transceiver means including a monolithic millimeter wave integrated circuit (MMIC) transceiver having a transmitter for transmitting a frequency modulated (FM) carrier signal and a receiver for receiving reflected signals thereof, said MMIC transceiver having a circuit including oscillation, amplification and signal mixing means and integrated onto a single monolithic chip;

antenna means coupled to the transceiver means for transmitting said FM carrier signal and receiving said reflected signals within a desired field;

control means for controlling the dynamic range of said radar system; and

processor means including a digital signal processor coupled to the transceiver means for analyzing received signals so as to detect the presence of objects within the field.

2. The radar system as defined in claim 1 further comprising a frequency modulator coupled between said digital signal processor and the transceiver circuit, said frequency modulator being adapted to provide a preselected modulation signal to the transceiver.

3. The radar system as defined in claim 2 comprising:

circuit means for providing intermediate frequency (IF) signals with target information.

4. The radar system as defined in claim 3 wherein said control means comprises:

an automatic gain control amplifier being adapted to receive an analog gain control signal from said digital signal processor and provide an output therefrom;

an analog-to-digital converter adapted to digitize the output of said automatic gain control amplifier and provide a digital signal to said digital signal processor; and

a digital-to-analog converter being adapted to receive a digital gain control signal from the digital signal processor and provide the analog gain control signal.

5. The radar system as defined in claim 1 wherein said transceiver circuit comprises:

a voltage controlled oscillator being adapted to receive a waveform modulation signal and generate the frequency modulated carrier signal; and

a first amplifier coupled to said voltage controlled oscillator for amplifying the frequency modulated carrier signal, said voltage controlled oscillator and said first amplifier forming said transmitter for providing the amplified frequency modulated carrier signal to the antenna means.

6. The radar system as defined in claim 5 wherein said transceiver circuit further comprises:

a second amplifier for receiving and amplifying the reflected signals received from said antenna means; and

a balanced mixer coupled to said second amplifier for receiving a reference transmit signal representative of said FM carrier signal and mixing the reference transmit signal with the received reflected signals so as to provide the difference therebetween, said second amplifier and said balanced mixer forming said receiver.

7. The radar system as defined in claim 6 wherein said MMIC transceiver further comprises:

a coupler for providing coupling and isolation between the transmitter and receiver and a transmit path to said antenna.

8. The radar system as defined in claim 7 wherein said MMIC transceiver further comprises:

a duplexer coupled between said transmitter and receiver for allowing said transmitted carrier signal to be transmitted from said transmitter to the antenna means, and further allowing the reflected signals to be transmitted from said antenna means to the receiver, said duplexer being further adapted to isolate the transmitter from the receiver, and wherein said reference transmit signal received by said balanced mixer is a leakage signal provided along a leakage path from said transmitter.

9. The radar system as defined in claim 8 wherein said antenna means comprises a microstrip patch antenna, said antenna being etched on a circuit board and including a plurality of patches being connected by microstrip lines.

10. The radar system as defined in claim 9 wherein said radar system is integrated into a small, compact, low profile module providing flexibility and modularity for said radar system.

11. The radar system as defined in claim 10 wherein said first and second amplifiers each comprise first and second amplification stages.

12. A compact highly integrated radar system for detecting objects within a desired field by detecting the beat frequency shift and the amplitude from reflected signals from objects located therein, said system comprising:

transceiver means including a monolithic millimeter wave integrated circuit (MMIC) transceiver having a transmitter for transmitting a frequency modulated carrier signal and a receiver for receiving the reflected signals thereof, said MMIC transceiver including a circuit having a controlled oscillator means, amplification means, mixing means and duplexer means integrated onto a single monolithic chip;

antenna means including a microstrip patch antenna coupled to the transceiver means for transmitting and receiving said signals within a desired field;

processor means including a digital signal processor coupled to the transceiver means for analyzing the received signal to detect the presence of objects within the field; and

control means for adjusting the dynamic range of the radar system.

13. The radar system as defined in claim 12 wherein said transmitter comprises:

a local voltage controlled oscillator for providing the frequency modulated carrier signal; and

first amplifier means including a transmitter amplifier coupled to said oscillator for amplifying the frequency modulated carrier signal.

14. The radar system as defined in claim 13 wherein said receiver comprises:

second amplifier means including a receiver amplifier for amplifying the reflected signal received from said antenna means; and

a balanced mixer coupled to said second amplifier means for receiving and mixing the reflected signals with a leakage signal representative of said carrier signal to provide an intermediate frequency by providing the difference between a reference transmit signal and said received signal.

15. The radar system as defined in claim 14 wherein said MMIC transceiver circuit further comprises:

a duplexer coupled between said transmitter and receiver for transmitting the carrier signal to the antenna and further transmitting received reflected signals from the antenna to the receiver and being adapted to provide isolation between said transmitter and receiver; and

a coupler being adapted to couple the transmitter and receiver to the antenna and further adapted to provide a reference transmit signal to the balanced mixer via a leakage path.

16. The radar system as defined in claim 15 wherein said control means comprises:

an automatic gain control amplifier being adapted to receive an analog gain control signal from said digital signal processor and provide an output therefrom;

an analog-to-digital converter adapted to digitize the output of said automatic gain control amplifier and provide a digital signal to said digital signal processor; and

a digital-to-analog converter being adapted to receive a digital gain control signal from the digital signal processor and provide the analog gain control signal.

17. A highly integrated radar system for detecting objects within a desired field, said system comprising:

transceiver means including a monolithic millimeter wave integrated circuit (MMIC) transceiver integrated on a single monolithic chip and having a circuit including an oscillator, at least one amplifier, a duplexer and a mixer and providing a transmitter for transmitting a frequency modulated (FM) carrier signal and a receiver for receiving reflected signals thereof;

antenna means including a microstrip patch antenna coupled to said transceiver means for transmitting said FM carrier signal and receiving said reflected signals within a desired field;

processor means including a digital signal processor coupled to said transceiver means for analyzing said received signals so as to detect the presence of objects within the desired field;

control means for providing dynamic range control of said radar system; and

a compact low profile housing for enclosing said radar system, wherein said transceiver means, antenna means, processor means and control means are highly integrated within said housing.