Apparatus and method for compensating for return loss of antenna of radar, and radar apparatus using same
The present disclosure relates to an antenna return loss compensation apparatus and method of a radar and a radar apparatus using the same. The antenna return loss compensation apparatus may include a compensation information calculator configured to calculate return loss compensation information for compensating for a frequency-band based antenna return loss, and a return loss compensator configured to apply return loss compensation information to a reception signal that is reflected from an object and is received, so as to generate a final reception signal, may calculate and store, in advance, compensation information for a return loss occurring in the antenna, may perform compensation associated with the magnitude of a reception signal when measurement is performed using the radar, so that the reception signal has the same magnitude, whereby a radar's performance deterioration attributable to the return loss of the antenna may be minimized.
1. An antenna return loss compensation apparatus of a radar, the apparatus being used for a radar apparatus for vehicle and comprising:
a compensation information calculator configured to calculate return loss compensation information for compensating for a frequency-band based antenna return loss;
a storage configured to store the return loss compensation information of a plurality of reception signals, wherein each of the return loss compensation information of the plurality of reception signals stored in the storage corresponds to a respective frequency and a respective antenna associated with each of the plurality of reception signals; and
a return loss compensator configured to compensate a reception signal, reflected from an object and received, using the stored return loss compensation information corresponding to the reception signal, reflected from the objected and received, to generate a final reception signal.
2. The apparatus of claim 1 , wherein the compensation information calculator obtains a change in a magnitude (amplitude) of a reception signal for each frequency, and performs inverse-compensation on the reception signal using the obtained change, so as to generate the final reception signal.
3. The apparatus of claim 2 , wherein the compensation information calculator calculates envelope information from a waveform of the reception signal, and generates the return loss compensation information corresponding to the envelope information.
4. The apparatus of claim 3 , wherein the envelope information is obtained by extracting points each at which a gradient is 0 from the waveform of the reception signal, and connecting the points.
5. The apparatus of claim 2 , wherein the compensation information calculator performs fast Fourier transform (FFT) on a flat signal having a constant frequency over time among reception signals so as to calculate an FFT power, calculates reception signal amplitude change information using the FFT power, and generates the return loss compensation information corresponding to the reception signal amplitude change information.
6. The apparatus of claim 2 , wherein the compensation information calculator performs sliding fast Fourier transform (FFT) on a chirp signal having a frequency increasing or decreasing over time among reception signals so as to calculate an FFT power, calculates reception signal amplitude change information using the FFT power, and generates the return loss compensation information corresponding to the reception signal amplitude change information.
7. The apparatus of claim 1 , wherein the return loss compensator amplifies a magnitude of the reception signal by an amount corresponding to the return loss compensation information, so as to generate the final reception signal.
8. A radar apparatus, comprising:
an antenna unit comprising one or more transmission antennas and one or more reception antennas;
a return loss compensation apparatus comprising a compensation information calculator configured to calculate return loss compensation information for compensating for a frequency-band based antenna return loss, a storage configured to store the return loss compensation information of a plurality of reception signals, wherein each of the return loss compensation information of the plurality of reception signals stored in the storage corresponds to a respective frequency and a respective reception antenna associated with each of the plurality of reception signals, and a return loss compensator configured to compensate a reception signal, reflected from an object and received, using the stored return loss compensation information corresponding to the reception signal, reflected from the object and received, to generate a final reception signal; and
a signal processor configured to process the final reception signal generated via compensation performed by the return loss compensation apparatus, to obtain information associated with the object.
9. The apparatus of claim 8 , wherein the compensation information calculator obtains a change in a magnitude (amplitude) of a reception signal for each frequency, and performs inverse-compensation on the reception signal using the change, so as to generate the final reception signal.
10. The apparatus of claim 9 , wherein the compensation information calculator calculates envelope information from a waveform of the reception signal, and generates the return loss compensation information corresponding to the envelope information.
11. The apparatus of claim 10 , wherein the envelope information is generated by extracting points each at which a gradient is 0, from the waveform of the reception signal, and connecting the points.
12. The apparatus of claim 9 , wherein the compensation information calculator performs fast Fourier transform (FFT) on a flat signal having a constant frequency over time among reception signals so as to calculate an FFT power, calculates reception signal amplitude change information using the FFT power, and generates the return loss compensation information corresponding to the reception signal amplitude change information.
13. The apparatus of claim 9 , wherein the compensation information calculator performs sliding fast Fourier transform (FFT) on a chirp signal having a frequency increasing or decreasing over time among reception signals so as to calculate an FFT power, calculates reception signal amplitude change information using the FFT power, and generates the return loss compensation information corresponding to the reception signal amplitude change information.
14. The apparatus of claim 8 , wherein the return loss compensator amplifies a magnitude of the reception signal by an amount corresponding to the return loss compensation information, so as to generate the final reception signal.
15. A return loss compensation method of a radar, the method being used for a radar apparatus for vehicle and comprising:
calculating return loss compensation information for compensating for a frequency-band based antenna return loss;
storing the return loss compensation information of a plurality of reception signals, wherein each of the return loss compensation information of the plurality of reception signals stored in a storage corresponds to a respective frequency and a respective antenna associated with each of the plurality of reception signals; and
compensating a reception signal, reflected from an object and received, using the stored return loss compensation information corresponding to the reception signal, reflected from the object and received, to generate a final reception signal.
16. The method of claim 15 , wherein the calculating of the return loss compensation information comprises: obtaining a change in a magnitude (amplitude) of a reception signal for each frequency; and performing inverse-compensation on the reception signal using the change so as to generate the final reception signal.
17. The method of claim 16 , wherein the calculating of the return loss compensation information comprises: calculating envelope information from a waveform of the reception signal; and generating the return loss compensation information corresponding to the envelope information.
18. The method of claim 16 , wherein the calculating of the return loss compensation information comprises: performing fast Fourier transform (FFT) on a flat signal having a constant frequency over time among reception signals so as to calculate an FFT power; calculating reception signal amplitude change information using the FFT power; and generating the return loss compensation information corresponding to the reception signal amplitude change information.
19. The method of claim 16 , wherein the calculating of the return loss compensation information comprises: performing sliding fast Fourier transform (FFT) on a chirp signal having a frequency increasing or decreasing over time among reception signals; calculating reception signal amplitude change information using the FFT power; and generating the return loss compensation information corresponding to the reception signal amplitude change information.
20. The apparatus of claim 1 , wherein the return loss compensation information of the plurality of reception signals relates to a change in a frequency-based signal amplitude for the respective frequency and the respective antenna associated with each of the plurality of reception signals.