Radar having structure able to suppress low-frequency noise
A vehicle radar. In the vehicle radar, a high-pass filter is disposed on a signal line connecting a transmitting chip and a receiving chip, the signal line allowing a local oscillation signal to be transferred therethrough. The high-pass filter prevents noise from being introduced through the signal line, along which the local oscillation signal is transferred. This prevents the accuracy of detection from being lowered by low-frequency noise generated from the interior of the vehicle radar. The high-pass filter connected to the signal line is embodied as a variety of configurations, thereby providing a structure able to effectively suppress low-frequency noise while maintaining the existing structure of the vehicle radar.
1. A radar comprising:
a transmitting chip connected to a transmitting antenna to transmit a signal outwardly via the transmitting antenna;
a plurality of receiving chips connected to a receiving antenna to receive a signal from an external source;
a plurality of signal lines connecting the transmitting chip to the plurality of receiving chips, respectively, to transfer a synchronization signal generated by the transmitting chip to the plurality of receiving chips, the synchronization signal causing frequencies of the plurality of receiving chips to be synchronized with a frequency used in the transmitting chip; and
high-pass filters connected to the plurality of signal lines, respectively, to filter a low-frequency component from the synchronization signal transferred along the plurality of signal lines.
2. The radar according to claim 1 , wherein each of the high-pass filters comprises one or more first stubs connected to a corresponding signal line of the plurality of signal lines in an intersecting direction and a second stub directly connecting an end of a corresponding one of the one or more first stubs to a ground layer located below the one or more first stubs.
3. The radar according to claim 2 , wherein each of the high-pass filters further comprises a dielectric disposed between the one or more first stubs and the ground layer, the second stub being disposed in a via provided in the dielectric.
4. The radar according to claim 2 , wherein the plurality of signal lines are disposed in a single direction, and the one or more first stubs connected to the corresponding signal line of the plurality of signal lines are disposed on a single side of the plurality of signal lines.
5. The radar according to claim 2 , wherein the plurality of signal lines are disposed in a single direction, the one or more first stubs connected to a signal line of the plurality of signal lines are disposed on one side of the plurality of signal lines, and the one or more first stubs connected to another signal line of the plurality of signal lines are disposed on the other side of the plurality of signal lines.
6. The radar according to claim 2 , wherein at least one first stub of the one or more first stubs connected to the corresponding signal line of the plurality of signal lines comprises a bend.
7. The radar according to claim 6 , wherein the at least one first stub comprises a plurality of bends.
8. The radar according to claim 2 , wherein two or more first stubs of the one or more first stubs are disposed at a same distance.
9. The radar according to claim 2 , wherein each of the one or more first stubs is configured such that a width of a portion thereof connected to the corresponding signal line differs from a width of a portion thereof connected to the second stub.
10. The radar according to claim 2 , wherein each of the one or more first stubs is configured such that a width thereof decreases in a direction from the corresponding signal line to the second stub.
11. A radar comprising:
a transmitting chip connected to a transmitting antenna to transmit a signal outwardly via the transmitting antenna;
a receiving chip connected to a receiving antenna to receive a signal from an external source;
a signal line connecting the transmitting chip and the receiving chip to transfer a synchronization signal generated by the transmitting chip to the receiving chip, the synchronization signal causing a frequency of the receiving chip to be synchronized with a frequency used in the transmitting chip; and
a high-pass filter connected to the signal line to filter a low-frequency component transferred along the signal line.
12. The radar according to claim 11 , wherein the high-pass filter comprises a first stub connected to the signal line and disposed in a direction intersecting the signal line and a second stub directly connecting an end of the first stub to a ground layer located below the first stub.
13. The radar according to claim 12 , wherein the high-pass filter further comprises a dielectric disposed between the first stub and the ground layer, the second stub being disposed in a via provided in the dielectric to connect the first stub and the ground layer.
14. The radar according to claim 12 , wherein the high-pass filter comprises a plurality of first stubs, each connected to one of a plurality of signal lines, and the at least one of the plurality of first stubs connected to the corresponding signal line of the plurality of signal lines comprises a bend.
15. The radar according to claim 12 , wherein the high-pass filter comprises a plurality of first stubs each connected to one of a plurality of signal lines and each of the plurality of first stubs is configured such that a width of a portion thereof connected to the corresponding signal line differs from a width of a portion thereof connected to the second stub.