KR20230037843A - An ultra high resolution radar device using a delay-locked loop - Google Patents

Abstract

The present invention provides an ultrahigh-resolution radar device using a delay-locked loop. The device comprises: a reference clock generator generating a reference clock having a prescribed period; and a pulse radar device receiving the reference clock to control transmission timing to output a radar transmission signal, and receiving an echo signal reflected from the target to control reception timing to receive a radar reception signal. The resolution of the pulse radar device is inversely proportional to the number of delay cells individually controlling the transmission timing and the reception timing. According to the present invention, radar resolution can be markedly improved by freely changing the level of a time delay between a transmission clock signal and a reception clock signal in a pulse radar system.

Description

An ultra high resolution radar device using a delay-locked loop}

The present invention relates to a pulse radar device, and more particularly, a super-resolution radar device using a delay synchronization loop capable of improving radar resolution by freely varying time delays of a transmission clock signal and a reception clock signal through independent delay synchronization loops. It is about.

In general, a radar device is a device capable of transmitting radio waves and receiving reflected waves, and can measure the time from the time the radio waves are transmitted to the time the reflected waves are received.

The radar device may detect the direction and position of an object that reflects the transmitted radio wave based on the measured time, and the radio wave used may be a signal in a band of several MHz to several tens of GHz.

Types of radar devices include pulse radar devices and continuous wave radar devices. The pulse radar device repeatedly transmits a transmission pulse signal and receives an echo signal reflected by an object.

That is, the pulse radar device acquires target information by receiving an echo signal returned by reflection of a transmission pulse signal on a target in a range in which a target can be found.

A range gating type pulse radar device may receive a reflected signal in a specific range by providing a delay element in a radar receiver and varying a delay.

On the other hand, a delay-locked loop (DLL) is one of the components used in almost all chips included in computers and smartphones.

When we send a desired clock signal from the first generation point to a block located far away, the time at which the high/low level of the clock occurs is different from the first point at the receiving point.

In addition, since buffers are installed here and there to prevent the strength from being weakened by the resistance of a long interconnect, additional delay is generated by the buffer, which increases the time between the reference clock and the rising event of the clock that actually arrives on the chip. (rising event timing) difference can be severe.

In a synchronous system, all circuits inside a chip must move a signal every one clock, and if this time is out of sync, problems such as metastability may occur.

At this time, a block that reduces the phase difference between the reference clock and the actual clock (output clock) arriving at the chip is the delay synchronization loop.

In this way, there is a method of further delaying the clock as a method of increasing the clock, which rises later than the desired time due to the long interconnection and intermediate buffers, at the same time as the original reference clock.

Delaying the deferred clock back by 2pi results in a delay of one cycle, resulting in a rising event occurring at the same time.

Thus, the delay synchronization loop functions as a negative feedback circuit that creates the required amount of time delay.

Registered Patent Publication US 11067678 B2 (2021.07.20)

The problem to be solved by the present invention is to receive a reference clock and independently control the transmission timing and the reception timing using an individual delay synchronization loop, thereby reducing the time difference between the reception delay signal and the transmission delay signal to improve the resolution of the pulse radar device It is to provide a super high-resolution radar device using a delay synchronization loop.

The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

An ultra-high resolution radar device using a delay synchronization loop according to an aspect of the present invention for solving the above problems includes a reference clock generator for generating a reference clock having a constant period; and a pulse radar device receiving the reference clock to control transmission timing to output a radar transmission signal, and receiving an echo signal reflected from a target to receive a radar reception signal by controlling reception timing. It is characterized in that the resolution of the pulse radar device is in inverse proportion to the number of delay cells individually controlling the transmission timing and the reception timing.

The pulse radar device of the ultra-high-resolution radar device using the delay synchronization loop according to an aspect of the present invention for solving the above problems receives the reference clock and outputs a transmission triggering signal having the transmission timing controlled. synchronization loop; a reception delay synchronization loop receiving the reference clock and outputting a reception sampling clock having the reception timing controlled; a control unit outputting a first selection signal for controlling the transmission timing and a second selection signal for controlling the reception timing; a transmitter receiving the transmission triggering signal and outputting the radar transmission signal through a transmission antenna; and a receiver configured to receive the radar reception signal through a reception antenna in response to the reception sampling clock. It is characterized in that it includes.

The transmission delay synchronization loop of the ultra-high resolution radar apparatus using the delay synchronization loop according to an aspect of the present invention for solving the above problems receives the reference clock, receives a plurality of transmission delay signals, and detects a phase difference, respectively. a first phase detection unit outputting a 1 phase detection signal; a first charge pump receiving the first phase detection signal and outputting a first phase control voltage controlling a delay of the signal; a first filter unit configured to receive the first phase control voltage, remove noise, and output a first loop-filtered signal; a transmission delay unit having N delay cells, generating the plurality of transmission delay signals passing through every 1 to N delay cells in response to the first loop filtering signal, and feeding back the plurality of transmission delay signals to the first phase detection unit; and a first multiplexer configured to receive the plurality of transmission delay signals and perform multiplexing by N X 1 in response to the first selection signal β to output a β-th transmission triggering signal; It is characterized in that it includes.

The reception delay synchronization loop of the ultra-high resolution radar apparatus using the delay synchronization loop according to an aspect of the present invention for solving the above problems receives the reference clock, receives a plurality of reception delay signals, and detects a phase difference, respectively. a second phase detection unit outputting 2 phase detection signals; a second charge pump receiving the second phase detection signal and outputting a second phase control voltage controlling a delay of the signal; a second filter unit configured to receive the second phase control voltage, remove noise, and output a second loop filtering signal; A reception delay having N-1 delay cells, generating the plurality of reception delay signals passing through every 1 to N-1 delay cells in response to the second loop filtering signal, and feeding them back to the second phase detector. wealth; and a second multiplexer configured to receive the plurality of reception delay signals and multiplex Nx1 in response to the second selection signal α to output an α-th reception sampling clock. It is characterized in that it includes.

The control unit of the ultra-high resolution radar device using a delay synchronization loop according to an aspect of the present invention for solving the above problems is β times according to the magnitudes of the first selection signal (β) and the second selection signal (α). It is characterized in that the time difference (t) is calculated by the delay difference between the th transmission triggering signal and the α th reception sampling clock.

T는 상기 펄스 레이더 장치의 송신 주기, N은 상기 송신 지연부 내 지연 셀의 개수, N-1은 상기 수신 지연부 내 지연 셀의 개수인 것을 특징으로 한다.The time difference (t) of the ultra-high resolution radar device using the delay synchronization loop according to an aspect of the present invention for solving the above problems is expressed as in Equation 1 below when α ≥ β, [Equation 1] One]

T is the transmission period of the pulse radar device, N is the number of delay cells in the transmission delay unit, and N-1 is the number of delay cells in the reception delay unit.

T는 상기 펄스 레이더 장치의 송신 주기, N은 상기 송신 지연부 내 지연 셀의 개수, N-1은 상기 수신 지연부 내 지연 셀의 개수인 것을 특징으로 한다.The time difference (t) of the ultra-high resolution radar device using the delay synchronization loop according to an aspect of the present invention for solving the above problems is expressed as in Equation 2 below when α < β, [Equation 2] 2]

T is the transmission period of the pulse radar device, N is the number of delay cells in the transmission delay unit, and N-1 is the number of delay cells in the reception delay unit.

The time difference (t) of the ultra-high-resolution radar device using the delay synchronization loop according to one aspect of the present invention for solving the above-mentioned problem is characterized in that it can be set to less than 1/6 of the constant period of the reference clock do.

T는 상기 펄스 레이더 장치의 송신 주기, N은 상기 송신 지연부 내 지연 셀의 개수, N-1은 상기 수신 지연부 내 지연 셀의 개수인 것을 특징으로 한다.[Equation 3]

T is the transmission period of the pulse radar device, N is the number of delay cells in the transmission delay unit, and N-1 is the number of delay cells in the reception delay unit.

In order to solve the above problem, the control unit of the super high resolution radar device using a delay synchronization loop according to an aspect of the present invention determines the number of transmission triggering signals and the number of reception sampling clocks based on the constant period of the reference clock. It is characterized in that it is controlled so that it is different.

Other specific details of the invention are included in the detailed description and drawings.

According to the present invention, the size of the time delay between the transmission clock signal and the reception clock signal can be freely varied in the pulse radar system, thereby significantly improving radar resolution.

In addition, the signal-to-noise ratio of the received signal is increased by controlling the magnitude of at least one of a time delay between multiple transmission clock signals, a time delay between multiple reception clock signals, and a time delay between a transmission clock signal and a reception clock signal, and a pulse radar system. It is possible to prevent a metastability problem that may occur due to a shift in the transmission/reception time of a signal.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

1 is a schematic configuration diagram of a system including a super-resolution radar device using a delay synchronization loop according to an embodiment of the present invention.
FIG. 2 is an internal block diagram of the pulse radar device 100 shown in FIG. 1 .
FIG. 3 is an internal block diagram of the transmit delay synchronization loop 110 shown in FIG. 2 .
FIG. 4 is an internal block diagram of receive delay synchronization loop 120 shown in FIG.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, only these embodiments are intended to complete the disclosure of the present invention, and are common in the art to which the present invention belongs. It is provided to fully inform the person skilled in the art of the scope of the invention, and the invention is only defined by the scope of the claims.

Terminology used herein is for describing the embodiments and is not intended to limit the present invention. In this specification, singular forms also include plural forms unless specifically stated otherwise in a phrase. As used herein, "comprises" and/or "comprising" does not exclude the presence or addition of one or more other elements other than the recited elements. Like reference numerals throughout the specification refer to like elements, and “and/or” includes each and every combination of one or more of the recited elements. Although "first", "second", etc. are used to describe various components, these components are not limited by these terms, of course. These terms are only used to distinguish one component from another. Accordingly, it goes without saying that the first element mentioned below may also be the second element within the technical spirit of the present invention.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used with meanings commonly understood by those skilled in the art to which the present invention belongs. In addition, terms defined in commonly used dictionaries are not interpreted ideally or excessively unless explicitly specifically defined.

The spatially relative terms "below", "beneath", "lower", "above", "upper", etc. It can be used to easily describe a component's correlation with other components. Spatially relative terms should be understood as including different orientations of elements in use or operation in addition to the orientations shown in the drawings. For example, if you flip a component that is shown in a drawing, a component described as "below" or "beneath" another component will be placed "above" the other component. can Thus, the exemplary term “below” may include directions of both below and above. Components may also be oriented in other orientations, and thus spatially relative terms may be interpreted according to orientation.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic configuration diagram of a system including a super high resolution radar device using a delay synchronization loop according to an embodiment of the present invention, including a reference clock generator 50, a pulse radar device 100 and a target 200 do.

2 is an internal block diagram of the pulse radar device 100 shown in FIG. 1, including a transmission delay synchronization loop 110, a reception delay synchronization loop 120, a control unit 130, a transmitter 140 and a receiver 150 includes

The function of each component of the pulse radar device 100 according to an embodiment of the present invention will be schematically described with reference to FIGS. 1 and 2 .

The reference clock generator 50 generates a reference clock having a constant cycle.

The pulse radar device 100 receives the reference clock from the reference clock generator 50, controls the transmission timing to output a radar transmission signal, receives the echo signal reflected from the target 200, and controls the reception timing to receive the radar. receive a signal

At this time, the transmission timing and the reception timing of the pulse radar device 100 are in inverse proportion to the number of delay cells individually controlling.

The transmission delay synchronization loop 110 receives a reference clock from the reference clock generator 50 and outputs a transmission triggering signal having a controlled transmission timing.

The reception delay synchronization loop 120 receives a reference clock and outputs a reception sampling clock whose reception timing is controlled.

The controller 130 outputs a first selection signal for controlling transmission timing and a second selection signal for controlling reception timing.

The transmitter 140 receives the transmission triggering signal and outputs a radar transmission signal through a transmission antenna.

The receiver 150 receives an echo signal reflected from the target 200 as a radar reception signal through a reception antenna in response to the reception sampling clock.

The operation of the ultra-high resolution radar device using the delay synchronization loop according to an embodiment of the present invention will be described in detail with reference to FIGS. 2 to 4 .

The reference clock generator 50 generates a reference clock having a constant cycle.

The pulse radar device 100 receives a reference clock from the reference clock generator 50, controls transmission timing through a transmission delay synchronization loop 110, and outputs a radar transmission signal.

That is, the transmission delay synchronization loop 110 in the pulse radar device 100 receives the reference clock and outputs a transmission triggering signal having a controlled transmission timing in response to the first selection signal β of the controller 130.

In addition, the reception delay synchronization loop 120 receives the reference clock and outputs a reception sampling clock whose reception timing is controlled in response to the second selection signal α of the control unit 130 .

The transmitter 140 receives the transmission triggering signal from the transmission delay synchronization loop 110 and outputs a radar transmission signal through the transmission antenna Tx ANT.

The target 200 spaced apart from the pulse radar device 100 by a predetermined distance receives and reflects the radar transmission signal output from the pulse radar device 100 to generate an echo signal.

The pulse radar device 100 receives a radar transmission signal in which the radar transmission signal reflected from the target 200 is delayed by a predetermined time, and has a transmission delay synchronization loop 110 and an independent reception delay synchronization loop 120 having a different number of delay cells. ) to control the reception timing to receive a super-high resolution radar reception signal.

That is, the receiver 150 transmits the echo signal generated from the target 200 in response to the reception sampling clock output from the reception delay synchronization loop 120 through the reception antenna Rx ANT to generate a time difference between the reception delay signal and the transmission delay signal. Receives a very high-resolution radar reception signal with significantly shortened .

At this time, the predetermined distance is calculated by Equation 1 below.

[Equation 1]

Here, C is the speed of light, and t represents the time difference between the radar transmission signal output from the transmission antenna and the radar reception signal received from the reception antenna.

FIG. 3 is an internal block diagram of the transmission delay synchronization loop 110 shown in FIG. 2, including a first phase detection unit 111, a first charge pump 112, a first filter unit 113, 114) and a first multiplexer 115.

A partial operation of the transmission delay synchronization loop 110 in the radar device according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 3 .

The first phase detection unit 111 receives a reference clock from the reference clock generator 50 and receives a plurality of transmission delay signals from the transmission delay unit 114, detects a phase difference, and outputs a first phase detection signal.

The first charge pump 112 receives the first phase detection signal from the first phase detection unit 111 and outputs a first phase control voltage for adjusting the delay of the signal.

The first filter unit 113 receives the first phase control voltage from the first charge pump 112 and removes noise to output a first loop filtering signal.

The transmission delay unit 114 includes N delay cells, and passes through every 1 to N delay cells in response to the first loop filtering signal applied from the first filter unit 113. A plurality of transmission delay signals are generated and fed back to the first phase detection unit 111 .

The first multiplexer 115 receives a plurality of transmission delay signals from the transmission delay unit 114, multiplexes them Nx1 in response to the first selection signal β, and outputs a β-th transmission triggering signal.

FIG. 4 is an internal block diagram of the reception delay synchronization loop 120 shown in FIG. 124) and a second multiplexer 125.

A partial operation of the reception delay synchronization loop 120 in the radar device according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 4 .

The second phase detection unit 121 receives a reference clock from the reference clock generator 50 and receives a plurality of delay signals from the reception delay unit 124, detects a phase difference, and outputs a second phase detection signal.

The second charge pump 122 receives the second phase detection signal from the second phase detection unit 121 and outputs a second phase control voltage for adjusting the delay of the signal.

The second filter unit 123 receives the second phase control voltage from the second charge pump 122 and removes noise to output a second loop filtering signal.

The reception delay unit 124 includes N-1 delay cells, and in response to the second loop filtering signal applied from the second filter unit 123, 1 to N-1 delay cells ), a plurality of delayed reception signals that have passed each time are generated and fed back to the second phase detection unit 121.

The second multiplexer 125 receives a plurality of reception delay signals from the reception delay unit 124, multiplexes (N-1) X 1 in response to the second selection signal α, and outputs an α-th reception sampling clock. do.

Referring to FIGS. 1 to 4, organic overall operations of the transmission delay synchronization loop 110 and the reception delay synchronization loop 120 according to an embodiment of the present invention will be described in detail.

Depending on the magnitudes of the first selection signal β and the second selection signal α output from the control unit 130, the time difference t due to the delay difference between the transmission delay signal and the reception delay signal is calculated as follows.

First, when α ≥ β, the time difference (t) between the delayed reception signal and the delayed transmission signal is expressed by Equation 2 below.

[Equation 2]

Here, T is a transmission period of the pulse radar device 100 and means a pulse repetition interval (PRI) or a pulse repetition frequency (PRF).

Also, N is the number of delay cells in the transmission delay unit 114, and N-1 is the number of delay cells in the reception delay unit 124.

On the other hand, when α < β, the time difference (t) between the delayed reception signal and the delayed transmission signal is expressed as Equation 3 below.

[Equation 3]

Here, T is the transmission period of the pulse radar device 100, N is the number of delay cells in the transmission delay unit 114, and N-1 is the number of delay cells in the reception delay unit 124.

Meanwhile, the resolution of the pulse radar device 100 is expressed as Equation 4 below.

[Equation 4]

Here, T is the transmission period of the pulse radar device 100, N is the number of delay cells in the transmission delay unit 114, and N-1 is the number of delay cells in the reception delay unit 124.

For example, when T = 100 [ns] and N = 4, t = 8.33 [ns], that is, a resolution of 1.25 [m] was shown, but in the pulse radar system actually implementing the present invention, T = 50 [ ns], N = 64, and t = 12.4 [ps], that is, shortened to 1.86 [mm], resulting in super-high resolution.

In addition, the time difference (t) between the delayed reception signal and the delayed transmission signal may be set to less than 1/6 of the reference clock period.

In addition, the control unit 130 sets the number of transmission triggering signals output by the transmission delay synchronization loop 110 and the number of reception sampling clocks output by the reception delay synchronization loop 120 to be different based on the period of the reference clock. Control.

In this case, the difference between the number of transmission triggering signals and the number of reception sampling clocks may be set not to exceed two.

As described above, the present invention receives the reference clock and independently controls the transmission timing and the reception timing using an individual delay synchronization loop, thereby shortening the time difference between the reception delay signal and the transmission delay signal to improve the resolution of the pulse radar device. A super high-resolution radar device using a loop is provided.

Through this, the size of the time delay between the transmission clock signal and the reception clock signal can be freely varied in the pulse radar system, and the radar resolution can be remarkably improved.

In addition, the signal-to-noise ratio of the received signal is increased by controlling the magnitude of at least one of a time delay between multiple transmission clock signals, a time delay between multiple reception clock signals, and a time delay between a transmission clock signal and a reception clock signal, and a pulse radar system. It is possible to prevent a metastability problem that may occur due to a shift in the transmission/reception time of a signal.

Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art to which the present invention pertains can be implemented in other specific forms without changing the technical spirit or essential features of the present invention. you will be able to understand Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

50: reference clock generator
100: pulse radar device
110: transmission delay synchronization loop
120: receive delay synchronization loop
130: control unit
140: transmitter
150: receiver
200: target

Claims (10)

a reference clock generator generating a reference clock having a constant cycle; and
a pulse radar device receiving the reference clock to control transmission timing to output a radar transmission signal, and receiving an echo signal reflected from a target to receive a radar reception signal by controlling reception timing;
including,
Characterized in that it is inversely proportional to the number of delay cells that individually control the transmission timing and the reception timing of the pulse radar device,
Ultra-high-resolution radar device using a delay synchronization loop.
According to claim 1,
The pulse radar device
a transmission delay synchronization loop receiving the reference clock and outputting a transmission triggering signal having the transmission timing controlled;
a reception delay synchronization loop receiving the reference clock and outputting a reception sampling clock having the reception timing controlled;
a control unit outputting a first selection signal for controlling the transmission timing and a second selection signal for controlling the reception timing;
a transmitter receiving the transmission triggering signal and outputting the radar transmission signal through a transmission antenna; and
a receiver configured to receive the radar reception signal through a reception antenna in response to the reception sampling clock;
Characterized in that it includes,
Ultra-high-resolution radar device using a delay synchronization loop.
According to claim 2,
The transmission delay synchronization loop is
a first phase detecting unit configured to receive the reference clock and a plurality of transmission delay signals, detect a phase difference, and output a first phase detection signal;
a first charge pump receiving the first phase detection signal and outputting a first phase control voltage controlling a delay of the signal;
a first filter unit configured to receive the first phase control voltage, remove noise, and output a first loop-filtered signal;
a transmission delay unit having N delay cells, generating the plurality of transmission delay signals passing through every 1 to N delay cells in response to the first loop filtering signal, and feeding back the plurality of transmission delay signals to the first phase detection unit; and
a first multiplexer configured to receive the plurality of transmission delay signals, multiplex NX 1 in response to the first selection signal β, and output a β-th transmission triggering signal;
Characterized in that it includes,
Ultra-high-resolution radar device using a delay synchronization loop.
According to claim 3,
The receive delay synchronization loop is
a second phase detector configured to receive the reference clock, receive a plurality of received delay signals, detect a phase difference, and output a second phase detection signal;
a second charge pump receiving the second phase detection signal and outputting a second phase control voltage controlling a delay of the signal;
a second filter unit configured to receive the second phase control voltage, remove noise, and output a second loop filtering signal;
A reception delay having N-1 delay cells, generating the plurality of reception delay signals passing through every 1 to N-1 delay cells in response to the second loop filtering signal, and feeding them back to the second phase detector. wealth; and
a second multiplexer receiving the plurality of reception delay signals, multiplexing NX 1 in response to the second selection signal α, and outputting an α-th reception sampling clock;
Characterized in that it includes,
Ultra-high-resolution radar device using a delay synchronization loop.
According to claim 4,
The control unit
Calculating a time difference (t) by a delay difference between the β-th transmission triggering signal and the α-th reception sampling clock according to the magnitudes of the first selection signal (β) and the second selection signal (α) to do,
Ultra-high-resolution radar device using a delay synchronization loop.
According to claim 5,
The time difference (t) is,
In the case of α ≥ β, it is expressed as in Equation 1 below,
[Equation 1]

Characterized in that T is the transmission period of the pulse radar device, N is the number of delay cells in the transmission delay unit, and N-1 is the number of delay cells in the reception delay unit,
Ultra-high-resolution radar device using a delay synchronization loop.
According to claim 5,
The time difference (t) is,
When α < β, it is expressed as in Equation 2 below,
[Equation 2]

Characterized in that T is the transmission period of the pulse radar device, N is the number of delay cells in the transmission delay unit, and N-1 is the number of delay cells in the reception delay unit,
Ultra-high-resolution radar device using a delay synchronization loop.
According to claim 5,
The time difference (t) is,
Characterized in that it can be set to less than 1/6 of the constant period of the reference clock,
Ultra-high-resolution radar device using a delay synchronization loop.
According to claim 1,
The resolution of the pulse radar device is
It is expressed as in Equation 3 below,
[Equation 3]

Characterized in that T is the transmission period of the pulse radar device, N is the number of delay cells in the transmission delay unit, and N-1 is the number of delay cells in the reception delay unit,
Ultra-high-resolution radar device using a delay synchronization loop.
According to claim 2,
The control unit
Characterized in that the number of transmission triggering signals and the number of reception sampling clocks are controlled to be different based on the constant period of the reference clock.
Ultra-high-resolution radar device using a delay synchronization loop.

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