Short range micro-power impulse radar with high resolution swept range gate with damped transmit and receive cavities
First Claim
1. A radar for detecting characteristics of objects within a field, comprising:
- a transmitter, including a shielded transmit cavity and a transmit antenna within the shielded transmit cavity, which transmits a sequence of electromagnetic signals from the transmit antenna into the field in response to a transmit timing signal;
a receiver, including a shielded receive cavity and a receive antenna within the shielded receive cavity, which samples echoes from objects in the field of the sequence of electromagnetic signals with controlled timing, in response to a receive timing signal, and generates a sample signal in response to the samples;
a timing circuit which supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver, the receive timing signal causing the receiver to sample the echoes such that time between transmission of signals in the sequence and sampling by the receiver sweeps over a range of delays; and
means, connected to the receive and transmit cavities, for reducing clutter in the sample signal.
3 Assignments
0 Petitions
Accused Products
Abstract
A radar range finder and hidden object locator is based on ultra-wide band radar with a high resolution swept range gate. The device generates an equivalent time amplitude scan with atypical range of 4 inches to 20 feet, and an analog range resolution as limited by a jitter of on the order of 0.01 inches. A differential sampling receiver is employed to effectively eliminate ringing and other aberrations induced in the receiver by the near proximity of the transmit antenna, so a background subtraction is not needed, simplifying the circuitry while improving performance. Uses of the invention include a replacement of ultrasound devices for fluid level sensing, automotive radar, such as cruise control and parking assistance, hidden object location, such as stud and rebar finding. Also, this technology can be used when positioned over a highway lane to collect vehicle count and speed data for traffic control. Techniques are used to reduce clutter in the receive signal, such as decoupling the receive and transmit cavities by placing a space between them, using conductive or radiative damping elements on the cavities, and using terminating plates on the sides of the openings.
159 Citations
42 Claims
-
1. A radar for detecting characteristics of objects within a field, comprising:
-
a transmitter, including a shielded transmit cavity and a transmit antenna within the shielded transmit cavity, which transmits a sequence of electromagnetic signals from the transmit antenna into the field in response to a transmit timing signal; a receiver, including a shielded receive cavity and a receive antenna within the shielded receive cavity, which samples echoes from objects in the field of the sequence of electromagnetic signals with controlled timing, in response to a receive timing signal, and generates a sample signal in response to the samples; a timing circuit which supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver, the receive timing signal causing the receiver to sample the echoes such that time between transmission of signals in the sequence and sampling by the receiver sweeps over a range of delays; and means, connected to the receive and transmit cavities, for reducing clutter in the sample signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
-
-
20. A radar for detecting characteristics of objects within a field, comprising:
-
a transmitter, including a shielded transmit cavity having a transmit opening with a perimeter and facing the field, and a transmit antenna within the shielded transmit cavity, which transmits a sequence of electromagnetic signals from the transmit antenna into the field in response to a transmit timing signal, each of the signals in the sequence having a duration of about 10 nanoseconds or less; a receiver, including a shielded receive cavity having a receive opening with a perimeter and facing the field, and a receive antenna within the shielded receive cavity, which samples echoes from objects in the field of the sequence of electromagnetic signals with controlled timing, in response to a receive timing signal, and generates a sample signal in response to the samples; a shielding base, supporting the shielded transmit cavity and the shielded receive cavity such that the transmit cavity is separated from the receive cavity, and shielding receiver and transmitter electronics; and a timing circuit, shielded by the shielding base, which supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver, such that a sampling interval between transmission of a given electromagnetic signal in the sequence and sampling of echoes of said given electromagnetic signal has a length of less than about 300 nanoseconds. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
-
-
35. A method for sensing characteristics of objects within a field, comprising:
-
transmitting a sequence of electromagnetic signals into the field from a transmit cavity with controlled timing, wherein electromagnetic signals in the sequence have a duration of about 10 nanoseconds or less, and a transmit interval between electromagnetic signals in the sequence has a length which exceeds 100 nanoseconds; sampling, at a receive cavity adjacent the transmit cavity with controlled timing, a sequence of echoes of the sequence of electromagnetic signals reflected from objects within the field, each echo in the sequence sampled within a sampling interval of time of less than 100 nanoseconds from the time of transmission of a corresponding electromagnetic signal in the sequence; connecting means for reducing clutter in the sampled signal to the receive and transmit cavities prior to the steps of transmitting and sampling; and processing the sampled sequence of echoes to indicate a characteristic of an object within the field. - View Dependent Claims (36, 37, 38, 39, 40, 41, 42)
-
Specification