APPARATUS AND METHOD FOR ATTENUATING CLOSE-RANGE RADAR SIGNALS IN AN AUTOMOTIVE RADAR SENSOR
A radar system and method include a first transmitted radar signal having a first frequency and a second transmitted radar signal having a second frequency different from the first frequency. A receiver receives reflected radar signals generated by reflection of the transmitted radar signals and generates receive signals indicative of the reflected radar signals, a first receive signal being indicative of a first reflected radar signal generated by reflection of the first transmitted radar signal, and a second receive signal being indicative of a second reflected radar signal generated by reflection of the second transmitted radar signal. A processor receives the first and second receive signals and computes a difference between the first and second receive signals to generate a difference signal, the processor processing the difference signal to provide radar information.
1 . A radar system, comprising:
a radar signal transmitter for transmitting transmitted radar signals into a region, a first transmitted radar signal having a first frequency and a second transmitted radar signal having a second frequency different from the first frequency;
a receiver for receiving reflected radar signals generated by reflection of the transmitted radar signals and generating receive signals indicative of the reflected radar signals, a first receive signal being indicative of a first reflected radar signal generated by reflection of the first transmitted radar signal, and a second receive signal being indicative of a second reflected radar signal generated by reflection of the second transmitted radar signal;
a processor receiving the first and second receive signals and computing a difference between the first and second receive signals to generate a difference signal, the processor processing the difference signal to provide radar information for the region.
2 . The radar system of claim 1 , wherein a difference between the first frequency and the second frequency is selected such that the information related to objects in the region near the radar system is attenuated in the difference signal.
3 . The radar system of claim 1 , wherein a difference between the first frequency and the second frequency is selected such that a phase difference between the first and second reflected radar signals is such that information related to objects in the region near the radar system is attenuated in the difference signal.
4 . The radar system of claim 1 , wherein the first frequency is approximately 24.2 GHz.
5 . The radar system of claim 1 , wherein a difference between the first frequency and the second frequency is approximately 11 MHz.
6 . The radar system of claim 1 , wherein the transmitted radar signals are pulse radar signals.
7 . The radar system of claim 6 , wherein a pulse of the pulse radar signals has a duration of approximately 120 nsec.
8 . The radar system of claim 1 , wherein the radar system is an automotive radar system.
9 . The radar system of claim 8 , wherein a difference between the first frequency and the second frequency is selected such that information related to objects in the region near the radar system is attenuated in the difference signal.
10 . The radar system of claim 9 , wherein the objects in the region near the radar system include a bumper fascia of an automobile in which the radar system is disposed.
11 . The radar system of claim 8 , wherein a difference between the first frequency and the second frequency is selected such that a phase difference between the first and second reflected radar signals is such that information related to objects in the region near the radar system is attenuated in the difference signal.
12 . The radar system of claim 8 , wherein the radar system is an automotive blind spot radar system.
13 . A detection method in a radar system, comprising:
transmitting transmitted radar signals into a region, a first transmitted radar signal having a first frequency and a second transmitted radar signal having a second frequency different from the first frequency;
receiving reflected radar signals generated by reflection of the transmitted radar signals;
generating receive signals indicative of the reflected radar signals, a first receive signal being indicative of a first reflected radar signal generated by reflection of the first transmitted radar signal, and a second receive signal being indicative of a second reflected radar signal generated by reflection of the second transmitted radar signal;
computing a difference between the first and second receive signals to generate a difference signal; and
processing the difference signal to provide radar information for the region.
14 . The method of claim 13 , further comprising selecting a difference between the first frequency and the second frequency such that information related to objects in the region near the radar system is attenuated in the difference signal.
15 . The method of claim 13 , further comprising selecting a difference between the first frequency and the second frequency such that a phase difference between the first and second reflected radar signals is such that information related to objects in the region near the radar system is attenuated in the difference signal.
16 . The method of claim 13 , wherein the first frequency is approximately 24.2 GHz.
17 . The method of claim 13 , wherein a difference between the first frequency and the second frequency is approximately 11 MHz.
18 . The method of claim 1 , wherein the transmitted radar signals are pulse radar signals.
19 . The method of claim 18 , wherein a pulse of the pulse radar signals has a duration of approximately 120 nsec.
20 . The radar system of claim 1 , wherein the radar system is an automotive radar system.
21 . The method of claim 20 , further comprising selecting a difference between the first frequency and the second frequency such that information related to objects in the region near the radar system is attenuated in the difference signal.
22 . The method of claim 21 , wherein the objects in the region near the radar system include a bumper fascia of an automobile in which the radar system is disposed.
23 . The method of claim 20 , further comprising selecting a difference between the first frequency and the second frequency such that a phase difference between the first and second reflected radar signals is such that information related to objects in the region near the radar system is attenuated in the difference signal.
24 . The method of claim 20 , wherein the radar system is an automotive blind spot radar system.