KR20190139736A - Radar apparatus - Google Patents

Abstract

The present invention provides a radar apparatus which provides high distance resolution. According to an embodiment of the present invention, the radar apparatus comprises: a controller to generate a variable delay control signal whose value varies over time; a clock generator to generate a transmission clock and a reception clock delayed more than the transmission clock by a delay time varying in accordance with the variable delay control signal; a transmitter to radiate a transmission pulse via a transmission antenna based on the transmission clock; a first receiver to receive a first echo pulse obtained as the transmission pulse is reflected from a target object via a first reception antenna, and generate a first restoration signal corresponding to the first echo signal based on the reception clock; and a second receiver to receive a second echo pulse obtained as the transmission pulse is reflected from the target object via a second reception antenna, and generate a second restoration signal corresponding to the second echo signal based on the reception clock. The controller acquires the distance of the target object based on at least one among a first delay time between the transmission clock and the reception clock corresponding to the first restoration signal and a second delay time between the transmission clock and the reception clock corresponding to the second restoration signal.

Description

Radar Device {RADAR APPARATUS}

The present invention relates to a radar device, and more particularly to a pulse radar device for emitting a pulse based on a clock signal, and obtains information about the target from the pulse reflected from the target.

The pulse radar apparatus repeatedly radiates a transmission pulse based on a transmission clock, and restores an echo pulse in which a transmission pulse is reflected back to a target based on the reception clock. The pulse radar device may obtain information about the target by analyzing the restored echo pulse.

The pulse radar apparatus may obtain the distance of the target and the azimuth information of the target by analyzing the echo pulse. In order to accurately obtain the distance of the target (i.e., to implement a high distance resolution), the delay between the transmit clock and the receive clock must be finely adjusted. However, it is not easy to finely adjust the delay between the transmit clock and the receive clock. In addition, in order to accurately obtain the azimuth of the target (ie, to implement high azimuth resolution), the pulse radar device may include a plurality of receivers arranged at various locations. However, when the pulse radar device includes a plurality of receivers, the size of the radar device may be large and power consumption may be high.

The present invention is to solve the above technical problem. It is an object of the present invention to provide high distance resolution by finely adjusting the delay between the transmit and receive clocks of a pulse radar device. In addition, the present invention provides a high azimuth resolution while minimizing the size of the pulse radar device.

A radar device according to an embodiment of the present invention includes a controller configured to generate a variable delay control signal whose value varies with time, a transmission clock, and the transmission clock by a delay time that varies according to the variable delay control signal. A clock generator configured to generate a delayed receive clock, a transmitter configured to emit a transmit pulse through a transmit antenna based on the transmit clock, receive a first echo pulse reflected from a target through a first receive antenna, and Receive a second echo pulse reflected by the transmission pulse from the target through a first receiver and a second receive antenna configured to generate a first recovery signal corresponding to the first echo pulse based on the received clock, Generate a second recovery signal corresponding to the second echo pulse based on the received clock; And a second receiver configured, wherein the controller comprises a first delay time between the transmit clock and the receive clock corresponding to the first recovery signal and between the transmit clock and the receive clock corresponding to the second recovery signal. And obtain a distance of the target based on at least one of the second delay times.

In one embodiment, the controller may be further configured to obtain an azimuth angle of the target based on a separation distance between the first receiving antenna and the second receiving antenna, the first delay time and the second delay time. Can be.

In one embodiment, the separation distance may be at least half of the wavelength of the center frequency of the transmission pulse.

In one embodiment, the variable delay control signal may vary continuously between a preset minimum value and a preset maximum value.

In one embodiment, the clock generator is configured to delay the reference clock based on a first delay control signal to generate the transmission clock, and delay the reference clock based on a second delay control signal. A second delay element configured to generate the receive clock, a phase comparator configured to compare a phase of the transmit clock and a phase of the receive clock to output a phase comparison output signal, and a difference between the phase comparison output signal and the variable delay control signal It may include an error amplifier configured to amplify the output delay signal.

In one embodiment, each of the first and second receivers is a low noise amplifier configured to amplify received echo pulses of the first and second echo pulses, the amplification in response to the received clock. A sampler configured to sample a sampled echo pulse to output a sampled signal, a variable amplifier configured to amplify the sampled signal, and convert the amplified sampled signal into a digital signal to convert the first reconstruction signal and the first signal. It may include an analog to digital converter configured to output one of the two recovery signals.

In one embodiment, the transmitter may include an oscillator configured to change the center frequency and bandwidth of the transmit pulse.

In one embodiment, the variable delay control signal is generated according to a predetermined period, and the controller may be further configured to output a control period signal synchronized with the predetermined period.

A radar device according to an embodiment of the present invention includes a controller configured to generate a variable delay control signal whose value varies with time, a transmission clock, and the transmission clock by a delay time that varies according to the variable delay control signal. A clock generator configured to generate a delayed receive clock, a first transmitter configured to emit a first transmit pulse through a first transmit antenna based on the transmit clock, a second transmit via a second transmit antenna based on the transmit clock Receive at least one echo pulse reflected from a target by the first transmit pulse and the second transmit pulses through a second transmitter and receive antenna configured to emit a pulse, and based on the received clock, the at least one echo pulse A receiver configured to generate at least one recovery signal corresponding to The controller is further configured to obtain a distance of the target based on a delay time between the transmit clock and the receive clock corresponding to the at least one recovery signal.

In one embodiment, the controller is further configured to obtain an azimuth angle of the target based on information analyzed from the waveform of the at least one reconstruction signal and a separation distance between the first transmit antenna and the second transmit antenna. Can be.

In one embodiment, the variable delay control signal may vary continuously between a preset minimum value and a preset maximum value.

In one embodiment, the clock generator is configured to delay the reference clock based on a first delay control signal to generate the transmission clock, and delay the reference clock based on a second delay control signal. A second delay element configured to generate the receive clock, a phase comparator configured to compare a phase of the transmit clock and a phase of the receive clock to output a phase comparison output signal, and a difference between the phase comparison output signal and the variable delay control signal It may include an error amplifier configured to amplify the output delay signal.

In one embodiment, the receiver is a low noise amplifier configured to amplify the received echo pulses, a sampler configured to sample the amplified echo pulses in response to the received clock to output a sampled signal, the And a variable amplifier configured to amplify a sampled signal and an analog-to-digital converter configured to convert the amplified sampled signal into a digital signal to output the reconstructed signal.

A radar device according to an embodiment of the present invention includes a controller configured to generate a variable delay control signal whose value varies with time, a transmission clock, and the transmission clock by a delay time that varies according to the variable delay control signal. A clock generator configured to generate a delayed receive clock, a transmitter configured to emit a transmit pulse through a transmit antenna based on the transmit clock, receive a first echo pulse reflected from a target through a first receive antenna, and Receive a second echo pulse reflected by the transmission pulse from the target through a first receiver and a second receive antenna configured to generate a first recovery signal corresponding to the first echo pulse based on the received clock, Generate a second recovery signal corresponding to the second echo pulse based on the received clock; And a second receiver configured, wherein the controller is configured to provide a first time ratio from the minimum distance detection time for the period of the variable delay control signal to the recovery time of the first recovery signal and the period for the period of the variable delay control signal. And obtain the distance of the target based on at least one of a second time ratio from the minimum distance detection time to the recovery time of the second recovery signal.

In one embodiment, the controller is azimuth angle of the target based on the difference between the distance of the first target obtained using the first time ratio and the distance of the second target obtained using the second time ratio. It may be further configured to obtain.

In one embodiment, the clock generator is configured to delay the reference clock based on a first delay control signal to generate the transmission clock, and delay the reference clock based on a second delay control signal. A second delay element configured to generate the receive clock, a phase comparator configured to compare a phase of the transmit clock and a phase of the receive clock to output a phase comparison output signal, and a difference between the phase comparison output signal and the variable delay control signal It may include an error amplifier configured to amplify the output delay signal.

In one embodiment, each of the first and second receivers is a low noise amplifier configured to amplify received echo pulses of the first and second echo pulses, the amplification in response to the received clock. A sampler configured to sample a sampled echo pulse to output a sampled signal, a variable amplifier configured to amplify the sampled signal, and convert the amplified sampled signal into a digital signal to convert the first reconstruction signal and the first signal. And an analog-to-digital converter configured to output a corresponding recovery signal of the two recovery signals.

According to an embodiment, the variable delay control signal may be a sawtooth wave type signal that is linearly increased or decreased between the preset minimum value and the preset maximum value.

In one embodiment, the variable delay control signal may be a signal that increases or decreases nonlinearly between the preset minimum value and the preset maximum value.

The pulse radar device according to the embodiment of the present invention can obtain the distance of the target and the azimuth of the target with high resolution.

In addition, according to an embodiment of the present invention, it is possible to provide a miniaturized pulse radar device, it is possible to implement an integrated pulse radar device at a low power.

1 is a view showing a schematic operation of the radar apparatus according to an embodiment of the present invention.
FIG. 2 is a block diagram illustrating one example of the radar device of FIG. 1.
3A and 3B show examples of the variable delay control signal generated from the controller of FIG. 2.
4 is a diagram illustrating an example of clocks and pulses generated according to the variable delay control signal of FIG. 3A.
FIG. 5 is a diagram illustrating examples of restoration signals received by the controller of FIG. 2 and a control period signal CPS output by the controller.
6 is a diagram illustrating how the controller of FIG. 2 obtains a distance of a target and an azimuth of the target.
7 is a block diagram illustrating a clock generator of FIG. 2.
8 is a block diagram illustrating the receiver of FIG. 2.
9 is a flowchart illustrating an operation of a radar apparatus according to an exemplary embodiment.
10 is a flowchart illustrating an operation of generating a transmission clock and a reception clock by a radar apparatus according to an exemplary embodiment.
FIG. 11 is a block diagram illustrating another exemplary embodiment of the radar apparatus of FIG. 1.
FIG. 12 is a diagram illustrating an example of a reconstruction signal generated from the radar apparatus of FIG. 11.
FIG. 13 is a diagram illustrating a method of obtaining, by the controller of FIG. 11, a distance of a target and an azimuth of the target.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, details such as detailed configurations and structures are provided merely to assist the overall understanding of the embodiments of the present invention. Therefore, modifications of the embodiments described in the present disclosure may be performed by those skilled in the art without departing from the spirit and scope of the present invention. Moreover, descriptions of well-known functions and structures are omitted for the sake of clarity and brevity. Terms used in the present specification are terms defined in consideration of the functions of the present invention, and are not limited to the specific functions. Definitions of terms may be determined based on matters described in the detailed description.

Modules in the following figures or detailed description can be connected to other than components shown in the drawings or described in the detailed description. Connections between modules or components can be direct or non-direct, respectively. The connections between the modules or components may each be a communication connection or a physical connection.

Unless defined otherwise, all terms including technical or scientific meanings used in the text have a meaning that can be understood by those skilled in the art. Generally, the terms defined in the dictionary are interpreted to have the same meaning as the contextual meaning in the related technical field, and are not interpreted to have the ideal or excessively formal meaning unless clearly defined in the text.

1 is a view showing a schematic operation of the radar apparatus according to an embodiment of the present invention. Referring to FIG. 1, the radar apparatus 100 may emit a transmission pulse TP. Alternatively, the radar apparatus 100 may transmit a transmission pulse TP toward the target. For example, the transmission pulse TP may include electromagnetic waves such as radio waves, infrared rays, visible rays, ultraviolet rays, X rays, and gamma rays.

The radar apparatus 100 may receive an echo pulse EP in which the transmission pulse TP is reflected back to the target. The radar apparatus 100 may obtain information about the target by analyzing the echo pulse EP. For example, the radar apparatus 100 may be a distance R (hereinafter, referred to as a distance R of a target) from the radar apparatus 100 to a target or an azimuth angle θ formed between the radar apparatus 100 and the target. (Hereinafter referred to as azimuth angle θ) of the target can be obtained.

The target may include a fixed object and a moving object. The radar apparatus 100 may obtain location information and velocity information of the object by obtaining a distance R and an azimuth angle θ of the fixed object and the moving object.

In exemplary embodiments, the radar apparatus 100 may emit a transmission pulse TP based on a transmission clock, and restore the received echo pulse EP based on the reception clock. The radar apparatus 100 may adjust a detection range of a target by controlling a delay time between a transmission clock and a reception clock. For example, the first delay time between the transmit clock and the receive clock may correspond to the first distance to the target, and the second delay time between the transmit clock and the receive clock may correspond to the second distance to the target. Accordingly, when the echo pulse EP is restored, the radar apparatus 100 may obtain the distance R of the target based on the delay information between the transmission clock and the reception clock.

The radar apparatus 100 may obtain the distance R of the target with high resolution by finely controlling the delay time between the transmission clock and the reception clock. A detailed description of an operation in which the radar apparatus 100 obtains the distance R of the target will be described with reference to the following drawings.

In exemplary embodiments, the radar apparatus 100 may transmit a transmission pulse TP through a transmitter. The transmit pulse TP hits the target and may be reflected to become an echo pulse EP. The radar device 100 may receive echo pulses EP at different locations through at least two receivers. The radar apparatus 100 may obtain the azimuth angle θ of the target based on a time difference in which the echo pulses EP are received.

In another example, the radar device 100 may emit transmit pulses TP at the same time through at least two transmitters. The radar apparatus 100 may receive at least two echo pulses EP through which the transmission pulses TP are reflected back to the target through the receiver. The radar apparatus 100 may obtain the azimuth angle θ of the target based on the time difference at which the echo pulses EP are received.

The radar apparatus 100 may obtain the azimuth angle θ of the target with high resolution through one transmitter and at least two receivers or at least two transmitters and one receiver. A detailed description of an operation in which the radar device 100 obtains the azimuth angle θ of the target will be described with reference to the drawings to be described later.

FIG. 2 is a block diagram illustrating one example of the radar device of FIG. 1. Referring to FIG. 2, the radar apparatus 100 may include a controller 110, a clock generator 120, a transmitter 130, a first receiver 140a, and a second receiver 140b.

The controller 110 may generate the variable delay control signal DCS and provide the variable delay control signal DCS to the clock generator 120. The variable delay control signal DCS may be a signal corresponding to a delay time between the transmission clock tCK and the reception clock dCK generated by the clock generator 120. That is, the controller 110 may control the delay time between the transmission clock tCK and the reception clock dCK using the variable delay control signal DCS.

The clock generator 120 may generate a transmission clock tCK and a reception clock dCK from the reference clock rCK. The clock generator 120 may generate the transmission clock tCK by delaying the reference clock rCK for a predetermined time. The clock generator 120 may generate the reception clock dCK by delaying the reference clock rCK such that the reception clock dCK is delayed from the transmission clock tCK by a delay time corresponding to the variable delay control signal DCS. have. The clock generator 120 may provide a transmission clock tCK to the transmitter 130 and provide a reception clock dCK to the first receiver 140a and the second receiver 140b.

The transmitter 130 may emit a transmission pulse TP through the transmission antenna 131 in response to the transmission clock tCK. For example, the transmitter 130 may emit a transmission pulse TP every rising edge of the transmission clock tCK.

The transmitter 130 may generate a transmission pulse TP to be emitted. The transmitter 130 may generate a transmission pulse TP having various center frequencies and bandwidths. In order to change the center frequency and bandwidth of the transmit pulse TP, the transmitter 130 may include an oscillator. The oscillator may generate a transmission pulse TP having a specific center frequency and a specific bandwidth according to a control signal provided from the controller 110. Accordingly, when the type of the detected target is changed or the situation in which the radar device 100 is applied is changed, the radar device 100 may change the center frequency and the bandwidth. For example, when detecting a target through the wall, the center frequency of the transmission pulse TP can be set low.

When the emitted transmit pulse TP is reflected on the target, the echo pulse EP may be received at various locations. As shown in FIG. 2, the first echo pulse EP1 may be received at the position of the first receiver 140a, and the second echo pulse EP2 may be received at the position of the second receiver 140b. have. The time at which each of the first echo pulse EP1 and the second echo pulse EP2 is received may vary depending on the positions of the first receiver 140a and the second receiver 140b. For example, when the first receiver 140a is closer to the target than the second receiver 140b, the first echo pulse EP1 may be received before the second echo pulse EP2.

Hereinafter, for convenience of explanation, it is assumed that the echo pulse EP received by the first receiver 140a is a first echo pulse EP1 and the echo pulse EP received by the second receiver 140b is represented. Assume that it is a second echo pulse EP2.

The first receiver 140a may receive a signal input through the first receiving antenna 141. The first receiver 140a may generate the first reconstruction signal RS1 corresponding to the received signal value in response to the reception clock dCK. For example, the first receiver 140a may generate the first recovery signal RS1 at the rising edge of the reception clock dCK. That is, the first receiver 140a may generate the first reconstruction signal RS1 corresponding to the signal value received at a specific time in response to the reception clock dCK.

For example, when the first echo pulse EP1 is not received at the rising edge of the reception clock dCK (for example, before the first echo pulse EP1 reaches the first reception antenna 141). Or when the first echo pulse EP1 reaches the receiving antenna 141 and passes by a time corresponding to the width of the first echo pulse EP1), the first receiver 140a receives the first echo pulse EP1. ) May generate the first reconstruction signal RS1 corresponding to the noise signal value. When the first echo pulse EP1 is received on the rising edge of the reception clock dCK (for example, when a specific value among the changing values of the first echo pulse EP1 is received), the first receiver 140a ) May generate a first recovery signal RS1 corresponding to a specific value of the first echo pulse EP1.

The second receiver 140b may receive a signal input through the second receive antenna 142. The second receiver 140b may generate a second recovery signal RS2 corresponding to the received signal value in response to the reception clock dCK. For example, the second receiver 140b may generate the second recovery signal RS2 at the rising edge of the reception clock dCK. That is, the second receiver 140b may generate a second recovery signal RS2 corresponding to the signal value received at a specific time in response to the reception clock dCK.

For example, when the second echo pulse EP2 is not received at the rising edge of the reception clock dCK (for example, before the second echo pulse EP2 reaches the second reception antenna 142). Alternatively, when the second echo pulse EP2 reaches the receiving antenna 142 and passes by a time corresponding to the width of the second echo pulse EP2), the second receiver 140b receives the second echo pulse EP2. Instead, the second recovery signal RS2 corresponding to the noise signal value may be generated. When the second echo pulse EP2 is received on the rising edge of the reception clock dCK (for example, when a specific value among the changing values of the second echo pulse EP2 is received), the second receiver 140b ) May generate a second recovery signal RS2 corresponding to a specific value of the second echo pulse EP2.

Since the positions of the first receiver 140a and the second receiver 140b are different, the time at which the first echo pulse EP1 and the second echo pulse EP2 arrive may be different. Accordingly, the first and second recovery signals RS1 and RS2 generated from the first and second receivers 140a and 140b are different from each other in response to the same reception clock dCK having the rising edge at the same time. Can be. For example, in response to the same reception clock dCK, the first receiver 140a generates the first recovery signal RS1 corresponding to the noise signal value, and the second receiver 140b generates the second echo pulse EP2. The second reconstruction signal RS2 corresponding to the specific value of) may be generated. Alternatively, in response to the same reception clock dCK, the first receiver 140a generates the first recovery signal RS1 corresponding to the first value of the first echo pulse EP1, and the second receiver 140b The second recovery signal RS2 corresponding to the second value of the second echo pulse EP2 may be generated.

As shown in FIG. 2, the reception antennas 141 and 142 may be positioned in line with the transmission antenna 131. The transmitting antenna 131 may be positioned in the center, and the receiving antennas 141 and 142 may be disposed to the left and right with respect to the transmitting antenna 131. However, the present invention is not limited thereto, and the reception antennas 141 and 142 and the transmission antenna 131 may be disposed at various locations. The distance between the receiving antennas 141 and 142 may be various values independent of the wavelength of the center frequency of the transmission pulse TP.

The radar apparatus 100 according to an embodiment of the present invention may generate one reconstruction signal from a receiver by using a reception clock after a time delay after radiating a transmission pulse TP using a transmission clock. That is, the radar apparatus 100 may generate one recovery signal from a pair of a transmission clock and a reception clock. The radar apparatus 100 may use a plurality of reconstruction signals to obtain information such as a distance and azimuth of a target.

For example, assume that the target is located at 3 m (pulse round trip time 20 nsec), and the transmission pulse width of the radar device 100 is 1 nsec. The radar device 100 emits a transmission pulse TP having a pulse width of 1 nsec by the transmission clock. When using a receive clock having a delay of less than 20 nsec to hit the target and return, the radar device 100 will receive a noise signal independent of the echo pulse EP. If using a receive clock having a delay of 20 nsec than the transmit clock, the radar device 100 may recover the beginning of the echo pulse EP (that is, the recovery corresponding to the beginning of the echo pulse EP). Signal may be generated). Assume that the radar device 100 generates a transmit and receive clock with a time delay of 20.01 nsec when the next pair of transmit and receive clocks is generated. Accordingly, the radar device 100 will restore the portion delayed by 0.01 nsec at the beginning of the echo pulse EP (that is, the restoration signal corresponding to the portion delayed by 0.01 nsec at the beginning of the echo pulse EP will be restored. Can be generated). Thereafter, the radar apparatus 100 may sequentially generate a pair of transmit and receive clocks having delay times of 20.02 nsec and 20.03 nsec. If the width of the echo pulse EP due to the transmission pulse TP having the width of 1 nsec is 1 nsec, the entire echo pulse EP will be recovered from the pair of 100 pairs of the transmission clock and the reception clock. After the entire echo pulse EP has been restored, if a receive clock having a delay of 21 nsec or more is used, the radar device 100 will recover a noise signal independent of the echo pulse EP.

As described above, the transmission pulse TP emitted according to the transmission clock tCK may be reflected from the target and received by the first receiver 140a and the second receiver 140b. In this case, the first recovery signal RS1 or the second recovery signal corresponding to the first echo pulse EP1 or the second echo pulse EP2 according to the delay time between the transmission clock tCK and the reception clock dCK. (RS2) may be generated. That is, when the delay time between the transmission clock tCK and the reception clock dCK is substantially the same as the time when the transmission pulse TP reaches the target and is reflected from the target to reach the receiving antenna, the receiver receives an echo pulse EP. May generate a recovery signal corresponding to

The controller 110 may receive the first recovery signal RS1 from the first receiver 140a and the second recovery signal RS2 from the second receiver 140b. The controller 110 may determine whether the first recovery signal RS1 or the second recovery signal RS2 is a value corresponding to the echo pulse EP. When the first recovery signal RS1 or the second recovery signal RS2 is a value corresponding to the echo pulse EP, the controller 110 corresponds to the first recovery signal RS1 or the second recovery signal RS2. The distance R of the target may be obtained based on the delay time between the transmission clock tCK and the reception clock dCK. For example, when the first recovery signal RS1 is equal to or greater than a threshold value, the controller 110 may determine that the first recovery signal RS1 is a value corresponding to the echo pulse EP. In this case, the controller 110 may use a method of removing background noise of the first recovery signal RS1. The controller 110 may obtain the distance R of the target based on a delay time between the transmission clock tCK and the reception clock dCK corresponding to the first recovery signal RS1.

The controller 110 may generate an azimuth angle of the target based on a difference between reception times of the first recovery signal RS1 corresponding to the first echo pulse EP1 and the second recovery signal RS2 corresponding to the second echo pulse EP2. (θ) can be obtained. For example, the first recovery signal RS1 corresponding to the first echo pulse EP1 may be received, and the second recovery signal RS2 corresponding to the second echo pulse EP2 may be received. In this case, the controller 110 transmits the first delay time between the transmission clock tCK corresponding to the first recovery signal RS1 and the reception clock dCK and the transmission clock tCK corresponding to the second recovery signal RS2. ) And the azimuth angle θ of the target based on the second delay time between the Rx and the received clock dCK.

Alternatively, the controller 110 may obtain the distance R of the target from each of the first recovery signal RS1 and the second recovery signal RS2 restored during one period. The controller 110 may obtain the azimuth angle θ of the target based on the difference in the distance R of the target obtained from each of the reconstruction signals RS1 and RS2.

Alternatively, the controller 110 uses the sum signal and the difference signal of the reconstruction signals RS1 and RS2 restored during one period, and the distance R of the target to the first receiver 140a and the second receiver 140b. The difference in the distance R of the target with respect to can be obtained. The controller 110 may obtain the azimuth angle θ of the target based on the difference in distance.

The variable delay control signal DCS may change continuously over time. The variable delay control signal DCS may vary continuously between a preset minimum value and a preset maximum value. The preset minimum value may correspond to the minimum delay time between the transmission clock tCK and the reception clock dCK, and the preset maximum value may correspond to the maximum delay time between the transmission clock tCK and the reception clock dCK. The delay time between the transmission clock tCK and the reception clock dCK may correspond to the detection distance of the target. Accordingly, the preset minimum value and the preset maximum value may indicate a detection distance section of the radar apparatus 100. That is, the controller 110 may continuously change the detection distance of the target by using the variable delay control signal DCS. Accordingly, the clock generator 120 may generate a reception clock dCK whose delay time is continuously changed.

The controller 110 may generate a variable delay control signal DCS that is repeated according to a predetermined period. The controller 110 may output the control period signal CPS synchronized with a predetermined period to provide the period information of the variable delay control signal DCS to the outside.

Hereinafter, the operation of the radar apparatus 100 will be described in detail with reference to FIGS. 3 to 6.

3A and 3B show examples of the variable delay control signal generated from the controller of FIG. 2. 3A and 3B, the horizontal axis represents time and the vertical axis represents the value of the variable delay control signal DCS. For example, the variable delay control signal DCS may be a voltage or current value corresponding to a delay time between the transmission clock tCK and the reception clock dCK.

Referring to FIG. 3A, the variable delay control signal DCS may continuously vary between a minimum value min and a maximum value max. The variable delay control signal DCS having the minimum value min at time t0 may increase linearly with time to have a maximum value max at time t4. The variable delay control signal DCS may repeatedly have a minimum value min and a maximum value max in accordance with a predetermined period PE. That is, as shown in FIG. 3A, the variable delay control signal DCS may be a sawtooth wave signal.

As the variable delay control signal DCS increases from the minimum value min to the maximum value max, a delay time between the transmission clock tCK and the reception clock dCK may increase. Accordingly, the time interval of the rising edge of the reception clock dCK may increase based on the rising edge of the transmission clock tCK, and the detection distance of the radar apparatus 100 may change from the minimum value to the maximum value. When the target is located between the minimum and maximum values of the detection distance, the radar apparatus 100 may detect the target based on the variable delay control signal DCS of one period PE.

As shown in Fig. 3A, the variable delay control signal value dcs1 of time t1 is a clock delay (hereinafter, used in the same sense as the delay time between the transmission clock tCK and the reception clock dCK) ( The variable delay control signal value dcs2 of time t2 corresponds to the clock delay cd2, and the variable delay control signal value dcs3 of time t3 corresponds to the clock delay cd3. Can be.

For example, if the target is located farther than the detection distance corresponding to the clock delay cd1, at time t1, the echo pulse EP is not detected based on the received clock dCK having the clock delay cd1. You may not. That is, the first receiver 140a of FIG. 2 may not generate the first recovery signal RS1 corresponding to the first echo pulse EP1 based on the reception clock dCK having the clock delay cd1. .

For example, when the target is located at a detection distance corresponding to the clock delay cd2, at time t2, the echo pulse EP may be detected based on the received clock dCK having the clock delay cd2. have. That is, the first receiver 140a of FIG. 2 may generate the first recovery signal RS1 corresponding to the first echo pulse EP1 based on the reception clock dCK having the clock delay cd2.

3A illustrates an example of the variable delay control signal DCS that is linearly increased from the minimum value min to the maximum value max, but the present invention is not limited thereto. For example, the controller 110 may generate a variable delay control signal DCS that is linearly reduced from the maximum value max to the minimum value min. As such, when the variable delay control signal DCS changes linearly, the radar apparatus 100 may detect the target with the same resolution from the minimum detection distance to the maximum detection distance.

Referring to FIG. 3B, the variable delay control signal DCS may vary continuously between a minimum value min and a maximum value max. The variable delay control signal DCS may increase nonlinearly with time between the minimum value min and the maximum value max during one period PE. The variable delay control signal DCS may increase rapidly in the area A1 around the minimum value min and slowly increase in the area A2 around the maximum value max.

The controller 110 may generate various types of non-linearly varying variable delay control signals DCS, as well as the variable delay control signals DCS illustrated in FIG. 3B. For example, the controller 110 may generate a variable delay control signal DCS that gradually increases in the area A1 and increases rapidly in the area A2. Alternatively, the controller 110 may generate a variable delay control signal DCS that is nonlinearly reduced from the maximum value max to the minimum value min. As such, when the variable delay control signal DCS changes nonlinearly, the radar apparatus 100 may be relatively finer (ie, at a detection distance corresponding to an area in which the slope of the variable delay control signal DCS is gentle). Targets can be detected (with higher resolution).

Hereinafter, for convenience of description, the operation of the clock generator 120, the transmitter 130, and the first and second receivers 140a and 140b of FIG. 2 based on the variable delay control signal DCS of FIG. 3A. Explain them in detail.

4 is a diagram illustrating an example of clocks and pulses generated according to the variable delay control signal of FIG. 3A. Specifically, the clocks tCK and dCK and the pulses TP, EP1 and EP2 illustrated in FIG. 4 may include the variable delay control signal at time t1, t2 and t3 as illustrated in FIG. 3A. Can be generated according to DCS). 4 represents the time. For convenience of explanation, the intervals between the times t1, t2, and t3 are shown to be wide, but the present invention is not limited thereto. For example, in order to obtain high resolution, the spacing between times t1, t2, t3 can be very small.

3A and 4, the clock generator 120 may generate a transmission clock tCK having a rising edge at times t1, t2, and t3. The clock generator 120 may receive the variable delay control signal DCS having the variable delay control signal value dcs1 at a time t1. The clock generator 120 may generate the reception clock dCK delayed by the clock delay cd1 based on the variable delay control signal value dcs1. The clock generator 120 may receive the variable delay control signal DCS having the variable delay control signal value dcs2 at a time t2. The clock generator 120 may generate the reception clock dCK delayed by the clock delay cd2 based on the variable delay control signal value dcs2. The clock generator 120 may receive the variable delay control signal DCS having the variable delay control signal value dcs3 at a time t3. The clock generator 120 may generate the reception clock dCK delayed by the clock delay cd3 based on the variable delay control signal value dcs3. Accordingly, the reception clock dCK may have a rising edge at times t1d, t2d, and t3d.

As shown in FIG. 4, as the variable delay control signal values dcs1, dcs2, and dcs3 increase, clock delays cd1, cd2, and cd3 may increase. Therefore, the detection distance of the radar apparatus 100 may be increased.

The transmitter 130 may emit a transmission pulse TP in response to the transmission clock tCK. The transmitter 130 may emit a transmission pulse TP every rising edges t1, t2, and t3 of the transmission clock tCK. When the transmission pulse TP is reflected on the target, the first echo pulse EP1 and the second echo pulse EP2 may be transmitted to the first receiver 140a and the second receiver 140b, respectively.

The first receiver 140a may generate the first reconstruction signal RS1 from the received signal in response to the reception clock dCK. As shown in FIG. 4, the first echo pulse EP1 may not be received at the time t1d, and the first echo pulse EP1 may be received at the time t2d and t3d. Accordingly, the first receiver 140a may generate a value corresponding to the noise value ns11 as the first recovery signal RS1 in response to the reception clock dCK having the clock delay cd1 at the time t1d. Can be. The first receiver 140a may generate a value corresponding to the first echo pulse value ep11 as the first recovery signal RS1 in response to the reception clock dCK having the clock delay cd2 at the time t2d. Can be. The first receiver 140a may generate a value corresponding to the first echo pulse value ep12 as the first recovery signal RS1 in response to the reception clock dCK having the clock delay cd3 at the time t3d. Can be.

The second receiver 140b may generate a second recovery signal RS2 from the received signal in response to the reception clock dCK. As shown in FIG. 4, the second echo pulse EP2 may not be received at the times t1d and t2d, and the second echo pulse EP2 may be received at the time t3d. Accordingly, the second receiver 140b may generate a value corresponding to the noise value ns21 as the second recovery signal RS2 in response to the reception clock dCK having the clock delay cd1 at the time t1d. Can be. The second receiver 140b may generate a value corresponding to the noise value ns22 as the second recovery signal RS2 in response to the reception clock dCK having the clock delay cd2 at the time t2d. The second receiver 140b may generate a value corresponding to the second echo pulse value ep21 as the second recovery signal RS2 in response to the reception clock dCK having the clock delay cd3 at the time t3d. Can be.

The first receiver 140a and the second receiver 140b have different positions relative to the target. Due to the path difference, the reception time of the first echo pulse EP1 and the second echo pulse EP2 may vary. Accordingly, a time difference (eg, a phase difference) between the first recovery signal RS1 generated by the first receiver 140a and the second recovery signal RS2 generated by the second receiver 140b. )) May occur.

As shown in FIG. 4, the first receiver 140a may recover the first echo pulse EP1 in response to the reception clock dCK having various clock delays. Similarly, the second receiver 140b may recover the second echo pulse EP2 in response to the reception clock dCK having various clock delays. That is, the first receiver 140a and the second receiver 140b may restore one value corresponding to a specific time point of the echo pulse EP for each rising edge of the reception clock dCK.

FIG. 5 is a diagram illustrating examples of restoration signals received by the controller of FIG. 2 and a control period signal CPS output by the controller. Specifically, in FIG. 5, the first recovery signal RS1, the second recovery signal RS2, and the control period signal CPS from the time t0 to the time t5 of FIG. 3A are illustrated.

3A, 4, and 5, the period PE from the time t0 to the time t4 is one period PE of the first receiver 140a. The variable delay control signal DCS is generated during this period, and the first receiver 140a may recover the first echo pulse EP1 using the reception clock dCK. For example, the first reconstruction signal value rs11 at the time t2d among the first reconstruction signals RS1 corresponds to the first echo pulse value ep11. Similarly, the first reconstruction signal value rs12 at time t3d may correspond to the first echo pulse value ep12.

In the above manner, the first receiver 140a may restore the first echo pulse EP1 during one period PE from the time t4 to the time t5. Accordingly, the controller 110 may receive the first recovery signal RS1 values of FIG. 5 from the first receiver 140a for one period from the time t0 to the time t5.

The controller 110 may determine a section corresponding to the first echo pulse EP1 of the first recovery signal RS1. For example, since the magnitude of the noise signal is generally smaller than the magnitude of the echo pulse EP, the controller 110 may determine values of the first recovery signal RS1 that are greater than or equal to a threshold indicating a specific magnitude. ) Can be determined. For example, as shown in FIG. 5, the controller 110 removes the first recovery signal value rs11 received at time t2d and the first recovery signal value rs13 received at time t4d. The value corresponding to one echo pulse EP1 can be determined.

The controller 110 may obtain the distance R of the target based on the first reconstruction signal value rs11 for one period PE from the time t0 to the time t4. The controller 110 may obtain the distance R of the target based on the first reconstruction signal value rs13 for one period PE from the time t4 to the time t5. For example, the controller 110 may obtain the distance R of the target from time t0 to time t4 using the clock delay cd2 corresponding to the first reconstruction signal value rs11. . For example, the controller 110 may obtain a time from the time corresponding to the minimum detection distance of one period PE to the time of restoration of the first restoration signal value rs11. The controller 110 may obtain the distance R of the target by using the ratio of the obtained time to the value of one period PE.

Alternatively, the controller 110 may obtain the distance R of the target from the reception time of each of the first recovery signal RS1 and the second recovery signal RS2 restored during one period. Hereinafter, an operation of obtaining the distance R of the target by the controller 110 will be described in detail with reference to FIG. 5.

5 shows reconstruction signals RS1 and RS2 composed of values reconstructed from a plurality of pairs of transmit and receive clocks. Therefore, these pulses are shown in the period PE of the variable delay control signal which is much longer than the period of the transmit pulse TP and the echo pulse EP. The variable delay control signal DCS increases linearly between the minimum and maximum values of the delay. That is, the radar apparatus 100 linearly detects a detection distance corresponding to the minimum value of the delay and a detection distance corresponding to the maximum value of the delay during the period PE of the variable delay control signal. The specific time of the period PE of the variable delay control signal may correspond to a specific detection distance between the minimum detection distance and the maximum detection distance. The radar device 100 may specify the location of the echo pulse EP from the restored signal. As an example of a method of specifying the position of the echo pulse EP, the controller 110 may specify the start point of the recovery signal value interval that is greater than or equal to the threshold value as the position of the echo pulse EP. The position of the specified echo pulse EP corresponds to a specific position of the period PE of the variable delay control signal. Therefore, the echo pulse EP may correspond to a specific detection distance between the minimum and maximum detection distances, and the radar apparatus 100 may determine the position (detection distance) of the target.

As another example of a method of specifying the position of the echo pulse EP, the controller 110 detects an envelope of the echo pulse EP to obtain a range in which the envelope exceeds a threshold, and centers the range of the echo pulse EP. It can be specified by the position of). As described above, the position of the target can be obtained from the position of the echo pulse EP.

As another example of a method of specifying the position of the echo pulse EP, the controller 110 may square the reconstruction signal to convert it into an energy signal and then apply a threshold to the converted signal. Alternatively, the controller 110 may detect an envelope of the converted signal to obtain a range where the envelope exceeds a threshold and specify the center of the range as the position of the echo pulse EP.

From time t0 to time t4, the second receiver 140b receives the second echo pulse EP2 based on the received clock dCK generated according to the variable delay control signal DCS for one period PE. Can be restored. For example, the second recovery signal value rs21 at the time t3d of the second recovery signal RS2 may correspond to the second echo pulse value ep21.

Similarly, from time t4 to time t5, the second receiver 140b may recover the second echo pulse EP2 during one period PE. Accordingly, the controller 110 may receive the second recovery signal RS2 of FIG. 5 from the time t0 to the time t5.

The controller 110 may determine a value corresponding to the second echo pulse EP2 among the second recovery signals RS2. For example, as shown in FIG. 5, the controller 110 removes the second recovery signal value rs21 received at time t3d and the second recovery signal value rs22 received at time t5d. It can be discriminated as corresponding to two echo pulses EP2.

The controller 110 may obtain the distance R of the target based on the second reconstruction signal value rs21 for one period PE from the time t0 to the time t4. The controller 110 may obtain the distance R of the target based on the second reconstruction signal value rs22 for one period PE from the time t4 to the time t5. For example, the controller 110 may obtain the distance R of the target by using the clock delay cd3 corresponding to the second reconstruction signal value rs21. Alternatively, the controller 110 may obtain the distance R of the target from the reception time of each of the restored signals RS1 and RS2 restored during one period PE.

As described above, in order to obtain the distance R of the target for one period PE from time t0 to time t4, the controller 110 performs a first recovery signal value rs11 and a second recovery. At least one of the signal values rs21 may be used. Since the clock delay cd2 corresponding to the first recovery signal value rs11 is smaller than the clock delay cd3 corresponding to the second recovery signal value rs21, the clock delay cd2 corresponding to the first recovery signal value rs11 is obtained based on the first recovery signal value rs11. The distance R obtained based on the distance R and the second reconstruction signal value rs21 may be slightly different. The distance R obtained when the position of the target is close and the distance between the receivers is far Can vary significantly. Thus, the distance R of the target may be determined by comparing the distance values of the target estimated from the signals reconstructed by the plurality of receivers.

For example, when the distance R of the target is obtained by using both the first recovery signal value rs11 and the second recovery signal value rs21, the controller 110 may include a clock delay cd2 and a clock delay ( The distance R of the target may be obtained based on the average value of cd3). Alternatively, the controller 110 may perform the first time from the time corresponding to the minimum detection distance of one period PE to the time of restoring the first restoration signal value rs11 and the time of restoring the second restoration signal value rs21. It is possible to obtain a second time of. The controller 110 may obtain the distance R of the target by using a ratio of the average value of the obtained first time and the second time to one period PE value.

The controller 110 may obtain the azimuth angle θ of the target based on the time difference between the first echo pulse EP1 and the second echo pulse EP2. For example, as shown in FIG. 5, the controller 110 may include a first reconstruction signal value corresponding to the first echo pulse EP1 for one period PE from time t0 to time t4. The azimuth angle θ of the target based on the reception time difference sd1 between the time t2d at which rs11 is received and the time t3d at which the second reconstruction signal value rs21 corresponding to the second echo pulse EP2 is received. ) Can be obtained. The reception time difference sd1 may be calculated from the clock delay cd2 and the clock delay cd3. In this case, a position indicated by the first restoration signal value rs11 in the first restoration signal RS1 and a position indicated by the second restoration signal value rs21 in the second restoration signal RS2 may correspond to each other. That is, the first reconstruction signal value rs11 and the second reconstruction signal value rs21 may be the same.

As described above, the controller 110 may specify the position of the echo pulse EP from the recovery signals RS1 and RS2 using various methods. For example, as shown in FIG. 5, the controller 110 may determine the location of the echo pulse EP by determining whether the recovery signal value at a specific time point is greater than or equal to a specific threshold value. If the relative positions of the receivers are differently positioned relative to the target, a time difference may occur between the echo pulses (EPs) recovered at each receiver. This time difference may be caused by a path difference relative to the target. The azimuth angle can be calculated using this path difference. The value of the time difference due to the path difference between the recovery signals RS1 and RS2 for one period PE from time t0 to time t4 may be "sd1". The reception time difference sd1 due to the path difference may be converted into a distance. The converted distance may correspond to a path difference. The controller 110 may calculate the azimuth angle θ from the path difference. Alternatively, the controller 110 may be configured to calculate the azimuth angle θ from the time point corresponding to the minimum detection distance of one period PE until the restoration time of the first recovery signal RS1. The first time is obtained, and the distance R of the first target may be obtained using the ratio of the obtained first time to the one period PE value. The controller 110 obtains a second time from a time point corresponding to the minimum detection distance of one period PE to a time point for restoring the second recovery signal RS2, and obtains the acquired second time value for one period PE. The distance R of the second target may be obtained using the ratio of time. The controller 110 may obtain a distance corresponding to the reception time difference sd2 from the difference between the distance R of the first target and the distance R of the second target. The controller 110 may calculate the azimuth angle θ from a distance corresponding to the reception time difference sd1.

The controller 110 performs a time t4d and a second when the first reconstruction signal value rs13 corresponding to the first echo pulse EP1 is received for one period PE from the time t4 to the time t5. The azimuth angle θ of the target may be obtained based on the reception time difference sd2 of the time t5d at which the second recovery signal value rs22 corresponding to the echo pulse EP2 is received. The reception time difference sd2 may be calculated from the clock delay cd4 and the clock delay cd5.

The controller 110 may convert the reception time difference sd2 into a distance. The converted distance may correspond to a path difference. The controller 110 may calculate the azimuth angle θ from the path difference.

Alternatively, the controller 110 obtains a first time from a time point corresponding to the minimum detection distance of one period PE to a time point for restoring the first recovery signal RS1, and obtains an acquired value for one period PE. The distance R of the first target may be obtained using the ratio of the first time. The controller 110 obtains a second time from a time point corresponding to the minimum detection distance of one period PE to a time point for restoring the second recovery signal RS2, and obtains the acquired second time value for one period PE. The distance R of the second target may be obtained using the ratio of time. The controller 110 may obtain a distance corresponding to the reception time difference sd2 from the difference between the distance R of the first target and the distance R of the second target. The controller 110 may calculate the azimuth angle θ from a distance corresponding to the reception time difference sd2.

As the time difference between the first echo pulse EP1 and the second echo pulse EP2 is smaller, the azimuth angle θ of the target may be smaller. As shown in FIG. 5, when the reception time difference sd1 is smaller than the reception time difference sd2, the azimuth angle θ of the target for one period PE from time t0 to time t4 is time. It may be smaller than the azimuth angle θ of the target for one period PE from t4 to time t5.

The controller 110 may output the control period signal CPS synchronized with the predetermined period PE to the outside. For example, as shown in FIG. 5, when the variable delay control signal DCS is the minimum value min (that is, time t0), the controller 110 outputs a control period signal CPS of a square wave. can do. Similarly, the controller 110 can output the square wave control period signal CPS at the time t4 at which the next period PE starts (that is, when the variable delay control signal DCS is at the minimum value min). have. When the control period signal CPS is output to the outside of the controller 110, various signal processors outside the controller 110 may analyze various information using the control period signal CPS. For example, the external signal processor may use the control period signal CPS to calculate the distance R of the target from the restoration signal RS.

Hereinafter, a method of obtaining the distance R of the target and the azimuth angle θ of the target will be described in detail with reference to FIG. 6.

6 is a diagram illustrating how the controller of FIG. 2 obtains a distance of a target and an azimuth of the target. In general, the distance between the transmit antenna 131 and the receive antennas 141, 142 is much smaller than the distance between the antennas 131, 141, 142 and the target, so that FIG. 6 is a diagram different from the actual distance. Can be. In the following, it is assumed that the distance between the transmitting antenna 131 and the receiving antennas 141, 142 is much smaller than the distance between the antennas 131, 141, 142 and the target.

Referring to FIG. 6, it may be assumed that the distance R from the radar apparatus 100 to the target is the distance R from the transmission antenna 131 to the target. As described with reference to FIG. 5, the controller 110 obtains a distance R1 from the first receiving antenna 141 to the target based on the first echo pulse EP1 received through the first receiving antenna 141. can do. The controller 110 may obtain a distance R2 from the second receiving antenna 142 to the target based on the second echo pulse EP2 received through the second receiving antenna 142. If the distance between the antennas 131, 141, 142 and the target is much greater than the distance between the transmitting antenna 131 and the receiving antennas 141, 142, the distance from the first receiving antenna 141 to the target ( Since the difference between the distance R2 from R1) and the second receiving antenna 142 to the target is very small compared to the distance R of the target, the distance R of the target is determined by the distance R1, distance R2 or It can be approximated by an average value of the distance R1 and the distance R2.

The first receiving antenna 141 may receive the first echo pulse EP1 through the first path P1. The second receiving antenna 142 may receive the second echo pulse EP2 through the second path P2. As shown in FIG. 6, when the azimuth angle θ of the target is not '0', a path difference pad may exist in the first path P1 and the second path P2. Due to the path difference pad, the time at which the first echo pulse EP1 and the second echo pulse EP2 are received may be different.

The path difference pad may be a function of the azimuth angle θ of the target and the separation distance rad between the first receiving antenna 141 and the second receiving antenna 142. For example, if the distance between the antennas 131, 141, 142 and the target is much greater than the distance between the transmit antenna 131 and the receive antennas 141, 142, the pad may be It may be represented as in Equation 1.

As described with reference to FIG. 5, the controller 110 may calculate a time difference at which the first echo pulse EP1 and the second echo pulse EP2 are received, and calculate a path pad from the difference in the reception time. Can be. The controller 110 may obtain the azimuth angle θ using the separation distance rad and the path difference pad based on Equation 1 above.

As described above, the radar apparatus 100 may generate the reception clock dCK based on the continuously varying variable delay control signal DCS. Accordingly, the radar apparatus 100 may precisely adjust the delay time between the transmission clock tCK and the reception clock dCK. The radar apparatus 100 may precisely analyze the delay relationship of the echo pulses EP1 and EP2 recovered from the reception clock dCK, and acquire the azimuth angle θ information of the target with high resolution. In addition, the radar apparatus 100 may obtain a delay relationship between the distance R of the target and the echo pulses EP1 and EP2 from the reception time of the echo pulses EP1 and EP2 restored during one period PE. Can be.

Since the radar apparatus 100 detects a target through a pulse and uses two receiving antennas 141 and 142, the separation distance rad between the two receiving antennas 141 and 142 may be freely determined. have. For example, the separation distance rad may be determined to be at least half of the wavelength of the center frequency of the transmission pulse TP. When the separation distance rad is increased, a path difference with respect to a target located at the same azimuth angle θ may increase. Accordingly, the radar apparatus 100 may analyze the increased path difference with respect to the same azimuth angle θ. That is, the resolution of the azimuth angle θ may be increased. As shown in Equation 1, when the separation distance rad is increased, a path pad may be increased with respect to the same azimuth angle θ.

7 is a block diagram illustrating a clock generator of FIG. 2. Referring to FIG. 7, the clock generator 120 may include a first delay element 121, a second delay element 122, a phase comparator 123, a filter 124, and an error amplifier 125.

The first delay element 121 may generate the transmission clock tCK by delaying the reference clock rCK based on the first delay control signal DS1. The first delay control signal DS1 may be a signal corresponding to a delay time between the reference clock rCK and the transmission clock tCK. The first delay control signal DS1 may be a preset specific value. In exemplary embodiments, the first delay control signal DS1 may be provided from the controller 110. The transmission clock tCK output from the first delay element 121 may be provided to the transmitter 130 and the phase comparator 123.

The second delay element 122 may generate the reception clock dCK by delaying the reference clock rCK based on the second delay control signal DS2. The second delay control signal DS2 may be a signal corresponding to a delay time between the reference clock rCK and the reception clock dCK. The value of the second delay control signal DS2 may vary according to the variable delay control signal DCS. The second delay control signal DS2 may be provided from the error amplifier 125. The reception clock dCK output from the second delay element 122 may be provided to the first and second receivers 140a and 140b and the phase comparator 123.

The phase comparator 123 may compare the phases of the transmission clock tCK and the reception clock dCK to output the phase comparison output signal CR. For example, the phase comparator 123 may output a square wave corresponding to a phase difference (ie, clock delay) between the transmission clock tCK and the reception clock dCK as the phase comparison output signal CR. In this case, the duty cycle of the square wave may be proportional to the phase difference.

The filter 124 may remove high frequency components included in the phase comparison output signal CR. For example, filter 124 may be a low pass filter. The filtered phase comparison output signal FCR output through the filter 124 may be provided to the error amplifier 125.

The error amplifier 125 may receive the filtered phase comparison output signal FCR and the variable delay control signal DCS and amplify the difference between the filtered phase comparison output signal FCR and the variable delay control signal DCS. have. For example, if the variable delay control signal DCS is greater than the filtered phase comparison output signal FCR (i.e., the delay time between the transmit clock tCK and the receive clock dCK is less than the desired delay time), The error amplifier 125 may output the increased second delay control signal DS2. Accordingly, the second delay element 122 receiving the second delay control signal DS2 may further increase the delay of the reference clock rCK to generate the reception clock dCK. If the variable delay control signal DCS is smaller than the filtered phase comparison output signal FCR (i.e., the delay time between the transmit clock tCK and the receive clock dCK is greater than the desired delay time), the error amplifier 125 ) May output the reduced second delay control signal DS2. Accordingly, the second delay element 122 receiving the second delay control signal DS2 may further reduce the delay of the reference clock rCK to generate the reception clock dCK.

As described above, the clock generator 120 may form a feedback path through which the output signal DS2 of the error amplifier 125 is input to the second delay element 122. Accordingly, the error between the delay time between the transmission clock tCK and the reception clock dCK and the desired delay time can be reduced. In addition, the clock generator 120 may not include a compensation circuit for the first and second delay elements 121 and 122. Accordingly, the miniaturized radar apparatus 100 may be implemented, and the radar apparatus 100 may operate at low power.

8 is a block diagram illustrating the receiver of FIG. 2. For convenience of description, FIG. 8 will be described with reference to the first receiver 140a. However, the present invention is not limited thereto, and the second receiver 140b may be implemented in the same manner as the first receiver 140a.

Referring to FIG. 8, the first receiver 140a may include a first receiving antenna 141, a low noise amplifier 143, a sampler 144, a variable amplifier 145, and an analog to digital converter 146. The first receiving antenna 141 may receive the first echo pulse EP1 and transmit the received first echo pulse EP1 to the low noise amplifier 143.

The low noise amplifier 143 may amplify the first echo pulse EP1. The amplified first echo pulse AEP1 may be provided to a sampler 144. The sampler 144 may sample the first echo pulse AEP1 amplified in response to the reception clock dCK. For example, the sampler 144 may sample the amplified first echo pulse AEP1 value at the rising edge of the receive clock dCK. The sampled signal SS may be provided to the variable amplifier 145.

The variable amplifier 145 may amplify the sampled signal SS. The amplified sampled signal ASS may be provided to the analog to digital converter 146. The analog-to-digital converter 146 may generate the first reconstruction signal RS1 by converting the amplified sampled signal ASS into a digital signal.

As described above, the first receiver 140a may sample a signal value received through the first reception antenna 141 in response to the reception clock dCK. That is, when the first echo pulse EP1 is received at the time when the reception clock dCK is provided, the first receiver 140a samples a value corresponding to the first echo pulse EP1, and the sampled signal ( The first reconstruction signal RS1 may be generated based on the SS.

9 is a flowchart illustrating an operation of a radar apparatus according to an exemplary embodiment. 2 and 9, in operation S101, the radar apparatus 100 may generate a transmission clock tCK and a reception clock dCK based on the variable delay control signal DCS. The variable delay control signal DCS may be a signal that varies continuously with time between a preset minimum value and a preset maximum value. The radar apparatus 100 may generate a reception clock dCK delayed by a delay time corresponding to the variable delay control signal DCS rather than the transmission clock tCK.

In operation S102, the radar apparatus 100 may emit a transmission pulse TP based on the transmission clock tCK. In operation S103, the radar apparatus 100 may receive an echo pulse EP in which the transmission pulse TP is reflected from the target. The echo pulse EP received by the first receiving antenna 141 of the radar device 100 is the first echo pulse EP1, and the echo pulse EP received by the second receiving antenna 142 is the second echo. It may be a pulse EP2. That is, the radar apparatus 100 may receive the first echo pulse EP1 through the first reception antenna 141 and the second echo pulse EP2 through the second reception antenna 142.

In operation S104, the radar apparatus 100 may generate first and second recovery signals RS1 and RS2 based on the reception clock dCK. The radar device 100 may generate the first recovery signal RS1 corresponding to the first echo pulse EP1 based on the reception clock dCK, and the second recovery signal corresponding to the second echo pulse EP2. The signal RS2 may be generated.

In operation S105, the radar apparatus 100 may obtain the distance R of the target and the azimuth angle θ of the target based on the first and second reconstruction signals RS1 and RS2. The radar apparatus 100 may obtain the distance R of the target based on a delay time between the transmission clock tCK and the reception clock dCK corresponding to at least one of the recovery signals RS1 and RS2. The radar apparatus 100 may specify the position of the echo pulse EP in the reconstruction signal, and obtain the distance R of the target from the specified position. The radar apparatus 100 may include a separation distance between the first receiving antenna 141 and the second receiving antenna 142, a clock delay corresponding to the first recovery signal RS1, and a clock corresponding to the second recovery signal RS2. The azimuth angle θ of the target can be obtained based on the delay. The radar apparatus 100 may measure the distance R and the second receiving antenna 142 from the first receiving antenna 141 to the first target from the receiving times of the signals RS1 and RS2 restored during one period PE. The distance R to the second target can be obtained. The radar apparatus 100 may obtain an azimuth angle θ based on a difference between the distance R to the first target and the distance R to the second target.

10 is a flowchart illustrating an operation of generating a transmission clock and a reception clock by a radar apparatus according to an exemplary embodiment. 2 and 10, in step S111, the radar apparatus 100 may receive a reference clock rCK. In operation S112, the radar apparatus 100 may generate the transmission clock tCK by delaying the reference clock rCK based on the first delay control signal DS1. In operation S113, the radar apparatus 100 may generate the reception clock dCK by delaying the reference clock rCK based on the second delay control signal DS2.

In operation S114, the radar apparatus 100 may output the phase comparison output signal CR by comparing the phase of the transmission clock tCK and the phase of the reception clock dCK. In operation S115, the radar apparatus 100 may output a second delay control signal DS2 by amplifying a difference between the phase comparison output signal CR and the variable delay control signal DCS. For example, the radar apparatus 100 may remove a high frequency component of the phase comparison output signal CR before amplifying the difference between the phase comparison output signal CR and the variable delay control signal DCS. The radar apparatus 100 may output the second delay control signal DS2 by amplifying a difference between the filtered phase comparison output signal and the variable delay control signal DCS.

FIG. 11 is a block diagram illustrating another exemplary embodiment of the radar apparatus of FIG. 1. Referring to FIG. 11, the radar apparatus 200 may include a controller 210, a clock generator 220, a first transmitter 230a, a second transmitter 230b, and a receiver 240. The operation of the controller 210 and the clock generator 220 is similar to the operation of the controller 110 and the clock generator 120 of FIG. 2, and the operation of the first transmitter 230a and the second transmitter 230b is illustrated in FIG. 2. The operation of the transmitter 130 may be similar to that of the receiver 240, and the operation of the first receiver 140a or the second receiver 140b may be similar. Accordingly, duplicate descriptions may be omitted. Hereinafter, the radar apparatus 200 of FIG. 11 will be described based on the differences from the radar apparatus 100 of FIG. 2.

The controller 210 may generate the variable delay control signal DCS and provide the variable delay control signal DCS to the clock generator 220. The clock generator 220 may generate a transmission clock tCK and a reception clock dCK from the reference clock rCK. The clock generator 220 may generate a reception clock dCK delayed by a delay time corresponding to the variable delay control signal DCS from the transmission clock tCK based on the variable delay control signal DCS.

The first transmitter 230a may radiate the first transmission pulse TP1 through the first transmission antenna 231 in response to the transmission clock tCK. The second transmitter 230b may emit the second transmission pulse TP2 through the second transmission antenna 232 in response to the transmission clock tCK. The first transmitter 230a and the second transmitter 230b may simultaneously emit the first transmission pulse TP1 and the second transmission pulse TP2.

The receiver 240 may receive echo pulses EP1 and EP2 input through the reception antenna 241. The receiver 240 may generate a recovery signal RS corresponding to the received signal value in response to the reception clock dCK. The receiver 240 receives the first echo pulse EP1 in which the first transmission pulse TP1 is reflected on the target and the second echo pulse EP2 in which the second transmission pulse TP2 is reflected on the target and returns. can do. When the first echo pulse EP1 and the second echo pulse EP2 are received through one receiver 240, the first echo pulse EP1 and the second echo pulse EP2 may overlap. Accordingly, the echo pulse SEP received by the receiver 240 by the first echo pulse EP1 and the second echo pulse EP2 overlaps the first echo pulse EP1 and the second echo pulse EP2. May be a pulse of a predetermined form. The receiver 240 may generate a recovery signal RS corresponding to the superimposed echo pulse SEP and provide it to the controller 210.

The waveform of the recovery signal RS may vary according to a difference in reception time of the first echo pulse EP1 and the second echo pulse EP2. The controller 210 may analyze the waveform of the reconstruction signal RS. The controller 210 may obtain the distance R of the target and the azimuth angle θ of the target based on the analyzed information. In exemplary embodiments, the controller 210 may determine the recovery signal RS corresponding to the echo pulse SEP. The controller 210 may obtain the distance R of the target based on the delay time between the transmission clock tCK and the reception clock dCK corresponding to the determined recovery signal RS. Alternatively, the controller 210 may obtain the distance R of the target from the reception time of the signal RS restored during one period PE.

In exemplary embodiments, the controller 210 may calculate a difference between a time when the first echo pulse EP1 is received and a time when the second echo pulse EP2 is received from the waveform of the recovery signal RS. The controller 210 may obtain the azimuth angle θ of the target based on the calculated reception time difference.

The controller 210 may output the control period signal CPS synchronized with a predetermined period to provide the period information of the variable delay control signal DCS to the outside.

As described above, the radar apparatus 200 may obtain the distance R of the target and the azimuth angle θ of the target using two transmitters 230a and 230b and one receiver 240. That is, in the case where the transmission pulses TP1 and TP2 are simultaneously transmitted at different positions, the radar apparatus 200 may acquire the position information and the speed information of the target through one receiver 240.

FIG. 12 is a diagram illustrating an example of a reconstruction signal generated from the radar apparatus of FIG. 11. 11 and 12, the receiver 240 may receive a first echo pulse EP1 and a second echo pulse EP2. Since the time at which the first transmission pulse TP1 and the second transmission pulse TP2 reach the target may vary according to the position of the target, the time when the first echo pulse EP1 is received and the second echo pulse EP2 are different. The time at which is received may be different. As illustrated in FIG. 12, the first echo pulse EP1 may be received earlier than the second echo pulse EP2 by the reception time difference sd.

As described with reference to FIG. 11, the first echo pulse EP1 and the second echo pulse EP2 may overlap. The receiver 240 may generate a recovery signal RS from the superimposed echo pulses SEP. The recovery signal RS may have a value corresponding to the superimposed echo pulse SEP. That is, the waveform of the recovery signal RS may be substantially the same as the waveform of the superimposed echo pulse SEP. The waveform of the echo pulse SEP may vary according to the difference in reception time of the first echo pulse EP1 and the second echo pulse EP2.

The controller 210 may analyze the waveform of the reconstruction signal RS. The controller 210 may determine that the echo pulse SEP has been received when the magnitude of the specific value rs of the recovery signal RS is greater than or equal to the threshold value. The controller 210 may obtain the distance R of the target based on the clock delay cd corresponding to the specific value rs. Alternatively, the controller 210 may obtain the distance R of the target from the reception time of the signal RS restored during one period PE.

The controller 210 may analyze the waveform of the reconstruction signal RS to obtain a reception time difference sd of the first echo pulse EP1 and the second echo pulse EP2. The controller 210 may obtain the azimuth angle θ of the target based on the reception time difference sd.

FIG. 13 is a diagram illustrating a method of obtaining, by the controller of FIG. 11, a distance of a target and an azimuth of the target. Unlike shown in FIG. 13, the distance between the transmit antennas 231, 232 and the receive antenna 241 may be much smaller than the distance between the antennas 231, 232, 241 and the target. In the following, it is assumed that the distance between the transmit antennas 231, 232 and the receive antenna 241 is much smaller than the distance between the antennas 231, 232, 241 and the target. The separation distance between the transmission antennas 231 and 232 may be arbitrarily set to a value equal to or greater than half the wavelength of the center frequency of the transmission pulses TP1 and TP2.

Referring to FIG. 13, it may be assumed that the distance R from the radar apparatus 200 to the target is the distance R from the reception antenna 241 to the target. As described with reference to FIG. 12, the controller 210 may obtain a distance R from the receiving antenna 241 to the target based on the superimposed echo pulse SEP received through the receiving antenna 241. When the separation distance between the transmitting antennas 231 and 232 is sufficient, the receiving antenna 241 may receive the separated echo pulses EP. In this case, as described above, the distance R and the azimuth angle θ of the target can be obtained.

The first transmission antenna 231 may transmit the first transmission pulse TP1 through the first path P1. The second transmit antenna 232 may transmit the second transmit pulse TP2 through the second path P2. As shown in FIG. 13, when the azimuth angle θ of the target is not '0', a path pad may exist in the first path P1 and the second path P2. Due to the path pad, the time at which the first transmission pulse TP1 and the second transmission pulse TP2 reach the target may be different. Accordingly, the time when the first echo pulse EP1 according to the first transmission pulse TP1 reaches the reception antenna 241 and the second echo pulse EP2 according to the second transmission pulse TP2 are determined by the reception antenna ( The time to reach 241 may vary. The receiving antenna 241 may receive an overlapping echo pulse SEP having a different shape according to a difference in reception time between the first echo pulse EP1 and the second echo pulse EP2.

The path difference pad may be a function of the azimuth angle θ of the target and the separation distance tad between the first transmit antenna 231 and the second transmit antenna 232. For example, if the distance between the antennas 231, 232, 241 and the target is much greater than the distance between the transmit antennas 231, 232 and the receive antenna 241, the path pad is It can be expressed as Equation 2.

As described with reference to FIG. 12, the controller 210 may obtain a difference in reception time between the first echo pulse EP1 and the second echo pulse EP2, and calculate a path pad from the difference in the reception time. have. The controller 210 may obtain the azimuth angle θ using the separation distance tad and the path difference pad based on Equation 2 above.

As described above, the radar apparatus 200 may generate the reception clock dCK based on the continuously varying variable delay control signal DCS. Accordingly, the radar apparatus 200 may precisely adjust the delay time between the transmission clock tCK and the reception clock dCK. The radar device 200 restores the superimposed echo pulses SEP based on the reception clock dCK, and accurately corrects the delay relationship between the first and second echo pulses EP1 and EP2 from the recovery signal RS. Can be analyzed. Therefore, the radar apparatus 200 may acquire the azimuth angle θ information of the target with high resolution.

As described above, the radar apparatus according to the embodiments of the present invention may include at least two receive antennas or at least two transmit antennas. For convenience of description, although two receiving antennas or two transmitting antennas are shown to be disposed in the vertical direction, the present invention is not limited thereto, and the receiving antenna and the transmitting antenna of the present invention may be arranged in various directions and at various intervals. Can be.

Components of the radar apparatus according to the embodiments of the present invention described above may be implemented in the form of software, hardware, or a combination thereof. By way of example, the software may be machine code, firmware, embedded code, and application software. For example, the hardware may include electrical circuits, electronic circuits, processors, computers, integrated circuits, integrated circuit cores, pressure sensors, inertial sensors, Micro Electro Mechanical Systems (MEMS), passive components, or combinations thereof. Can be.

The foregoing is specific embodiments for practicing the present invention. The present invention will include not only the above-described embodiments but also embodiments that can be simply changed in design or easily changed. In addition, the present invention will also include techniques that can be easily modified and practiced using the embodiments. Therefore, the scope of the present invention should not be limited to the above-described embodiments, but should be determined by the equivalents of the claims of the present invention as well as the following claims.

100, 200: radar device
110, 210: controller
120, 220: clock generator
130, 230a, 230b: transmitter
131, 231, 232: transmit antenna
140a, 140b, 240: receiver
141, 142, 241: receiving antenna

Claims (19)

A controller configured to generate a variable delay control signal whose value varies with time;
A clock generator configured to generate a receive clock delayed from the transmit clock by a delay time that varies according to a transmit clock and the variable delay control signal;
A transmitter configured to emit a transmit pulse through a transmit antenna based on the transmit clock;
A first receiver configured to receive a first echo pulse in which the transmit pulse is reflected from a target through a first receive antenna, and generate a first reconstruction signal corresponding to the first echo pulse based on the receive clock; And
A second receiver configured to receive a second echo pulse reflected by the transmission pulse from the target through a second receive antenna, and generate a second recovery signal corresponding to the second echo pulse based on the received clock; and,
The controller is configured to perform at least one of a first delay time between the transmission clock and the reception clock corresponding to the first recovery signal and a second delay time between the transmission clock and the reception clock corresponding to the second recovery signal. A radar device further configured to obtain a distance of the target based on the distance. The method of claim 1,
And the controller is further configured to obtain an azimuth angle of the target based on a separation distance between the first receive antenna and the second receive antenna, the first delay time and the second delay time. The method of claim 2,
The separation distance is at least half of a wavelength of a center frequency of the transmission pulse. The method of claim 1,
And the variable delay control signal continuously varies between a preset minimum value and a preset maximum value. The method of claim 1,
The clock generator,
A first delay element configured to delay the reference clock based on a first delay control signal to generate the transmission clock;
A second delay element configured to delay the reference clock based on a second delay control signal to generate the received clock;
A phase comparator configured to compare a phase of the transmit clock and a phase of the receive clock to output a phase comparison output signal; And
And an error amplifier configured to amplify a difference between the phase comparison output signal and the variable delay control signal to output the second delay control signal. The method of claim 1,
Each of the first receiver and the second receiver,
A low noise amplifier configured to amplify received echo pulses of the first echo pulse and the second echo pulse;
A sampler configured to sample the amplified echo pulse and output a sampled signal in response to the received clock;
A variable amplifier configured to amplify the sampled signal; And
And an analog-to-digital converter configured to convert the amplified sampled signal into a digital signal to output a corresponding reconstruction signal of the first reconstruction signal and the second reconstruction signal. The method of claim 1,
And the transmitter comprises an oscillator configured to change the center frequency and bandwidth of the transmit pulse. The method of claim 1,
The variable delay control signal is generated according to a predetermined period,
And the controller is further configured to output a control period signal synchronized with the predetermined period. A controller configured to generate a variable delay control signal whose value varies with time;
A clock generator configured to generate a receive clock delayed from the transmit clock by a delay time that varies according to a transmit clock and the variable delay control signal;
A first transmitter configured to emit a first transmit pulse through a first transmit antenna based on the transmit clock;
A second transmitter configured to emit a second transmit pulse through a second transmit antenna based on the transmit clock; And
Receive at least one echo pulse reflected from the target by the first transmission pulse and the second transmission pulse through a receiving antenna, and based on the received clock at least one recovery signal corresponding to the at least one echo pulse Includes a receiver configured to generate,
And the controller is further configured to obtain a distance of the target based on a delay time between the transmit clock and the receive clock corresponding to the at least one recovery signal. The method of claim 9,
And the controller is further configured to obtain an azimuth angle of the target based on information analyzed from a waveform of the at least one reconstruction signal and a separation distance between the first transmit antenna and the second transmit antenna. The method of claim 9,
And the variable delay control signal continuously varies between a preset minimum value and a preset maximum value. The method of claim 9,
The clock generator,
A first delay element configured to delay the reference clock based on a first delay control signal to generate the transmission clock;
A second delay element configured to delay the reference clock based on a second delay control signal to generate the received clock;
A phase comparator configured to compare a phase of the transmit clock and a phase of the receive clock to output a phase comparison output signal; And
And an error amplifier configured to amplify a difference between the phase comparison output signal and the variable delay control signal to output the second delay control signal. The method of claim 9,
The receiver,
A low noise amplifier configured to amplify the received echo pulse;
A sampler configured to sample the amplified echo pulse and output a sampled signal in response to the received clock;
A variable amplifier configured to amplify the sampled signal; And
And an analog-to-digital converter configured to convert the amplified sampled signal into a digital signal to output the reconstructed signal. A controller configured to generate a variable delay control signal whose value varies with time;
A clock generator configured to generate a receive clock delayed from the transmit clock by a delay time that varies according to a transmit clock and the variable delay control signal;
A transmitter configured to emit a transmit pulse through a transmit antenna based on the transmit clock;
A first receiver configured to receive a first echo pulse in which the transmit pulse is reflected from a target through a first receive antenna, and generate a first reconstruction signal corresponding to the first echo pulse based on the receive clock; And
A second receiver configured to receive a second echo pulse reflected by the transmission pulse from the target through a second receive antenna, and generate a second recovery signal corresponding to the second echo pulse based on the received clock; and,
The controller may include the first time ratio from the minimum distance detection time point for the period of the variable delay control signal to the recovery time point of the first reconstruction signal and the first time detection time point for the minimum distance detection time point for the period of the variable delay control signal. 2. The radar device further configured to obtain a distance of the target based on at least one of a second time ratio up to a restoration point of the restoration signal. The method of claim 14,
The controller is further configured to obtain an azimuth angle of the target based on a difference between the distance of the first target obtained using the first time ratio and the distance of the second target obtained using the second time ratio. . The method of claim 14,
The clock generator,
A first delay element configured to delay the reference clock based on a first delay control signal to generate the transmission clock;
A second delay element configured to delay the reference clock based on a second delay control signal to generate the received clock;
A phase comparator configured to compare a phase of the transmit clock and a phase of the receive clock to output a phase comparison output signal; And
And an error amplifier configured to amplify a difference between the phase comparison output signal and the variable delay control signal to output the second delay control signal. The method of claim 14,
Each of the first receiver and the second receiver,
A low noise amplifier configured to amplify received echo pulses of the first echo pulse and the second echo pulse;
A sampler configured to sample the amplified echo pulse and output a sampled signal in response to the received clock;
A variable amplifier configured to amplify the sampled signal; And
And an analog-to-digital converter configured to convert the amplified sampled signal into a digital signal to output a corresponding reconstruction signal of the first reconstruction signal and the second reconstruction signal. The method of claim 14,
The variable delay control signal is a sawtooth wave-shaped signal that is linearly increased or decreased between the preset minimum value and the preset maximum value. The method of claim 14,
And the variable delay control signal is a signal that is nonlinearly increased or decreased between the preset minimum value and the preset maximum value.

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