KR100767413B1 - Radar apparatus with transmitter leakage canceller - Google Patents

Abstract

A radar apparatus having a transmission leakage current canceller is provided to constrain the reduction of receiving intensity and a noise index of a receiving stage by using the transmission signal canceller without loss of transmission power. A radar apparatus having a transmission leakage current canceller includes a signal generator(101), a front coupler block(303), two intermediate coupler blocks(302), a rear coupler block(304), a leakage current canceller(301), a power divider(102) and two mixers(106). The front coupler block(303) divides a transmission signal generated from the signal generator(101) into two signals having the same amplitude and a phase difference of 90 degrees. The intermediate coupler blocks(302) receive the transmission signal from the front coupler block(101) and generate a quadrature signal. The intermediate coupler blocks(302) receive a receiving signal and generate a transmission leakage signal. The rear coupler block(304) receives the transmission signal having the phase difference of 90 degrees from the intermediate coupler blocks(302), and transmits the transmission signal to an antenna without loss. The rear coupler block(304) outputs the received signal having the phase difference of 90 degrees and the same amplitude to the intermediate coupler blocks(302). The leakage signal canceller(301) removes the transmission leakage signal and adds the received signal. The power divider(102) receives the signal outputted from the leakage signal canceller(301), and divides the received signal into two same signals. The mixers(106) perform quadrature mixing based on an LO signal outputted from the intermediate coupler block(302) and the signal outputted from the power divider(102).

Description

Radar apparatus with transmitter leakage signal canceller {Radar apparatus with transmitter leakage canceller}

1A is a block diagram schematically illustrating an example of a radar apparatus according to the related art, and illustrates a structure in which a transmitting and receiving antenna is shared;

FIG. 1B is a block diagram schematically showing another example of a radar device according to the prior art, showing a structure in which a transmitting and a receiving antenna are separately written;

2 is a block diagram schematically showing a radar apparatus according to the present invention;

3 is a view showing a specific configuration example of the radar device of FIG.

4 is a diagram showing examples of the configuration of the shear coupler block of FIG.

FIG. 5 is a diagram illustrating configuration examples of the rear coupler block of FIG. 2; FIG.

FIG. 6 is a view showing configuration examples of the leak signal remover of FIG. 2; FIG.

7 is a block diagram schematically showing another configuration of the radar apparatus according to the present invention; And

8 is a diagram illustrating a specific configuration example of the radar device of FIG. 7.

Explanation of symbols on the main parts of the drawings

101: Oscillator

102: Power Divider

103: Power Amplifier

104, 104a 104b: Antenna

105: Low Noise Amplifier

106: Mixer

107 Filter

201: signal separation element

202: termination resistor

301: Leakage Signal Eliminator

302: Interrupted Coupler Block

303: Shear Coupler Block

304: rear coupler block

401: Quadrature Coupler

402: 90 degree phase shift block

403: Combiner

The present invention relates to a radar device, and more particularly to a radar device having a transmission leakage signal canceller.

FIG. 1A is a block diagram schematically illustrating an example of a radar apparatus according to the related art, and illustrates a structure in which a transmitting and a receiving antenna are shared. Referring to FIG. 1, the radar apparatus includes a transmitting end 110, an antenna 104, a receiving end 120, and a signal separation device 201. The transmitter 110 transmits a transmission signal, and includes an oscillator 101, a power divider 102, and a power amplifier 103. The signal separation device 201 is for separating a transmission signal from a reception signal. Herein, a Lange coupler is used as the signal separation device 201. In addition, a circulator, divider or A device such as an isolator can also be used. The receiver 120 is for receiving a received signal separated from the signal separation device 201, and includes a low noise amplifier 105, a mixer 106 for comparing the reference signal LO, and a filter ( 107). The reference signal LO is used through the power divider 102 of the transmitting end 110. In FIG. 1A, reference numeral 202 denotes a termination resistor in which 50 Ω is typically used. When implementing a radar device sharing one antenna 104 for transmission and reception as shown in Figure 1a, there is an advantage that the size of the entire device can be reduced because only one antenna is used, but for the signal separation device 201 Since the isolation and transmission of devices such as circulators, combiners or dividers used are very low in the millimeter wave band, the signal coming from the output of the oscillator 101 flows into the receiving end 120 and the radar device The reception sensitivity becomes low, making it difficult to detect a weak reception signal. In addition, the low noise amplifier 105 or the mixer 106 constituting the receiver 120 may be saturated to deteriorate the characteristics of the entire radar device. In addition, the noise figure of the receiver 120 becomes worse due to a large leakage signal of the transmitter 110.

In order to solve this problem, as shown in FIG. 1B, a radar device that separates a transmitting antenna and a receiving antenna may be used. More specifically, Figure 1b is a block diagram schematically showing another example of the radar device according to the prior art, showing a structure in which the transmitting and receiving antennas are written separately. Referring to FIG. 1B, the radar apparatus includes a transmitting end 110 and a receiving end 120. The transmitter 110 transmits a transmission signal and includes an oscillator 101, a power divider 102, a power amplifier 103, and a transmission antenna 104a. The receiving end 120 is for receiving a received signal and includes a receiving antenna 104b, a low noise amplifier 105, a mixer 106 and a filter 107 for comparison with a reference signal LO. As shown in FIG. 1B, when the transmitting antenna 104a and the receiving antenna 104b are separated, the reception sensitivity of the radar device is improved and the receiver saturation because the isolation between the transmitting end and the receiving end is better than when using the circulator, coupler, or divider. However, the use of two antennas increases the size of the radar device. Moreover, the antenna occupies the largest area in the radar device, making it difficult to implement a micro radar device.

 And in order to obtain direction information about whether the target object is approaching or moving away, the quadrature mixer must be implemented. In order to operate the quadrature mixer, the quadrature signal must be generated from the local oscillator. This requires additional circuitry to generate an additional 90 degree phase difference, which complicates the system.

The present invention has been made to solve the above problems, and the technical problem of the present invention is to provide a radar device capable of canceling the leakage signal of the transmission stage by entering a transmitter leakage signal canceller without loss of transmission power. will be.

Another technical problem of the present invention is to provide a radar device capable of quadrature mixing and measuring the direction and displacement of an object.

Radar device according to an aspect of the present invention:

A signal generator;

A front coupler block configured to output two signals having the same magnitude and 90 degrees out of phase from the signal generator;

Two interrupted coupler blocks receiving the transmission signal from the front end coupler block, generating a quadrature signal, receiving the received signal, and generating an inevitable transmission leakage signal therein;

A rear end coupler block which receives a transmission signal having a 90 degree phase difference from the interrupt coupler block and adds it without loss to the antenna and transmits the received signal to the antenna having the same magnitude and a 90 degree phase difference to the interrupt coupler block;

A leakage signal canceller for removing the transmission leakage signal while adding up the reception signal;

A power divider for receiving a signal from the leakage signal canceller and dividing the signal into two identical signals;
Two mixers for performing quadrature mixing using the LO signal from the interrupt coupler block and the signal from the power divider;

And a baseband signal from which the transmission leakage signal is removed.

Radar device according to another aspect of the present invention is:

A signal generator;

A front coupler block configured to output two signals having the same magnitude and 90 degrees out of phase from the signal generator;

Two interrupted coupler blocks for receiving and transmitting a transmission signal from the front end coupler block and receiving a reception signal as well as generating an inevitable transmission leakage signal therein;

Receives a 90-degree phase difference transmitted from the interrupted coupler block and transmits it without loss to the antenna and transmits the received signal from the antenna to the rear coupler block having the same magnitude and 90-degree phase difference to send to the interrupted coupler block ;

A leakage signal canceller for removing the transmission leakage signal while adding up the reception signal;

A mixer performing mixing using the LO signal from the signal generator and the signal from the leakage signal canceller;

And a baseband signal from which the transmission leakage signal is removed.

In the two aspects of the present invention, it is preferable to further include a power amplifier between the signal generator and the front end coupler block, and a low noise amplifier between the leakage signal canceller and the mixer, respectively.

In one aspect of the present invention, it is preferable to use any one selected from the group of quadrature couplers consisting of a directional coupler, a Lange coupler and a branch line coupler as the stop coupler block, and in another aspect of the present invention, the quad It is preferable to use a structure in which the termination resistor is combined with any one selected from the group of the rusher couplers.

In both aspects of the invention, the shear coupler block is comprised of a termination resistor and any one selected from the group of quadrature couplers consisting of a directional coupler, a Lange coupler and a branch line coupler, or a power divider and a 90 degree phase shift block. It is preferable to make it.

In either aspect of the invention, the rear end coupler block is made of a termination resistor and any one selected from the group of quadrature couplers consisting of a directional coupler, a Lange coupler and a branch line coupler, or a combiner and a 90 degree phase shift block. It is preferable to make it.

In both aspects of the invention, the leakage signal canceller is comprised of a termination resistor and any one selected from the group of quadrature couplers consisting of a directional coupler, a Lange coupler and a branch line coupler, or a 90 degree phase shift with the combiner. It is desirable to have a block.

In the two aspects of the present invention, it is preferable that the combiner and the power divider each have a Wilkinson-type three-port structure.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. This embodiment is not intended to limit the scope of the present invention, but is presented by way of example only and the same reference numerals and names are used for the same parts as the conventional configuration.

2 is a block diagram schematically illustrating a radar apparatus according to the present invention. Referring to FIG. 2, after the output signal from the oscillator 101 passes through the power amplifier 103, it enters the front end coupler block 303 and comes out as an output signal having the same magnitude and 90 degrees out of phase with each other. The shear coupler block 303 for producing such an output signal is, for example, a combination of the quadrature coupler 401 and the termination resistor 202 as shown in Fig. 4A, or in Fig. 4B. As shown, the power divider 102 and the 90 degree phase shift block 302 can also use quadrature couplers, such as directional couplers, Lange couplers, branch line couplers, and the like. As the power divider 102, one having a Wilkinson-type three-port structure can be used. When viewed from the front coupler block 303, the isolation port of the two interrupted coupler blocks 302 generates a transmit leakage signal of 90 degrees out of phase. It also emits two outputs, each the same size and 90 degrees out of phase. One of the two signals from the output of each break coupler block 302 enters the LO signal of the mixer 106 and the other enters the input signal of the trailing coupler block 304. At this time, the two signals, which are LOs of the two mixers 106, have a phase difference of 90 degrees, thereby enabling quadrature mixing. The rear end coupler block 304 may be composed of a quadrature coupler 401 and a termination resistor 202 as shown in FIG. 5A, and a 90 degree phase shift block 402 as shown in FIG. 5B. And a combiner (403). The combiner 403 may be one having a Wilkinson-type three-port structure. Since the two input signals of the trailing coupler block 304 are 90 degrees out of phase, they are summed without loss of transmit power and transmitted to the antenna 104. When the signal exiting through the antenna 104 hits an object and enters through the antenna 104 again, it outputs two output signals with a 90 degree phase difference through the rear coupler block 304. These two output signals see power loss through the interrupt coupler block 302. The two signals of each break coupler block 302 are combined in the leak signal canceller 301. At this time, the two leakage signals generated during transmission are removed by the leakage signal canceller 301. 6 is a diagram illustrating configuration examples of the leak signal remover of FIG. 2. The leakage signal canceller 301 has two input ports. The input of one side of the transmitter leakage signal entering the leakage signal canceller 301 is the same in magnitude and 90 degrees out of phase compared to the other input. On the contrary, the signal reflected from the target object is delayed by 90 degrees on the opposite side to which the leakage signal is delayed by 90 degrees. Therefore, when the leakage signal canceller 301 is composed of the quadrature coupler 401 and the termination resistor 202 as shown in FIG. 6A, the leakage signal is summed into the termination resistor 202 and the phase is reversed at the opposite output. Combined and removed. On the contrary, the signal hitting the object is summed to the output port, not to the terminal having the termination resistor 202. In addition, as shown in (b) of FIG. 6, the combiner 403 and the 90 degree phase shift block 402 may be used to remove the leakage signal and add the signal returned by hitting the object. The combined signal is passed through the low noise amplifier 105, split into two identical signals through the power divider 102, enters the quadrature mixer 106, and is converted into a baseband signal through the filter 107.

Figure 3 shows a specific configuration example of the radar apparatus according to the present invention. Comparing FIG. 3 with FIG. 2, the shear coupler block 303 of FIG. 2 is a combination of quadrature coupler 401 and termination resistor 202 in FIG. 3, and the interrupt coupler block 302 of FIG. 2 is FIG. 3. In FIG. 3, the rear coupler block 304 of FIG. 2 is embodied as a combination of the quadrature coupler 401 and the termination resistor 202. In addition, the leak signal remover 301 of FIG. 2 is embodied by the combiner 403 and the 90 degree phase shift block 402 in FIG. Except for using the components specified in this way, the configuration and operation of the radar device shown in FIG. 3 is the same as that described in FIG.

7 is a block diagram schematically showing another configuration of a radar apparatus according to the present invention, and more specifically, a block diagram of a radar structure in the case of not performing quadrature mixing. Referring to FIG. 7, since only one mixer 106 is used unlike FIG. 2, it can be seen that quadrature mixing is not performed. In addition, only one output from the interrupt coupler block 302 is input to the trailing coupler block 304. The LO signal for the mixer 106 uses one of the two outputs of the break coupler block 302 in FIG. 2, but uses the one from the oscillator 101 in FIG. 7. The radar apparatus having such a configuration is the same as the case described in FIG. 2 except that quadrature mixing does not occur.

8 is a diagram illustrating a specific configuration example of the radar device of FIG. 7. This device also uses the transmitter leakage signal canceller 301, which connects the quadrature signal generation port to the termination resistor 202 when using a four-port coupler, which is a quadrature coupler 401, with two interrupt coupler blocks 302. To terminate. In addition, one of the signals from the generator 101 is provided to the input of the front end coupler block 303 and the other to the LO signal of the mixer 106. In this case, the two interrupt coupler blocks 302 may be replaced by a circulator instead of the quadrature coupler 401 and the termination resistor 202. Comparing Figs. 8A and 8B, the difference is that in Fig. 8A, the leakage signal canceller 301 is composed of a quadrature coupler 401 and a termination resistor 202. In FIG. 8B, the leak signal canceller 301 is composed of a combination of a combiner 403 and a 90 degree phase shift block 402.

According to the present invention as described above, since the transmitter leakage signal canceller without transmission power loss is used to remove the leakage signal of the transmitter, the transmission and reception antenna can be shared, so that the miniaturization is possible, and the transmitter leakage signal canceller without transmission power loss. Because of this, it is possible to reduce the reception sensitivity due to the transmitter leakage signal, reduce the noise figure of the receiver and saturation of the receiver circuit. In addition, when using the apparatus according to an aspect of the present invention capable of quadrature mixing, it is possible to measure the direction and displacement of the object, there is an advantage that can obtain a radar device of a very small, high sensitivity, high performance characteristics.

Claims (20)

A signal generator; A front coupler block configured to output two signals having the same magnitude and 90 degrees out of phase from the signal generator; Two interrupted coupler blocks receiving the transmission signal from the front end coupler block, generating a quadrature signal, receiving the received signal, and generating an inevitable transmission leakage signal therein; A rear end coupler block which receives a transmission signal having a 90 degree phase difference from the interrupt coupler block and adds it without loss to the antenna and transmits the received signal to the antenna having the same magnitude and a 90 degree phase difference to the interrupt coupler block; A leakage signal canceller for removing the transmission leakage signal while adding up the reception signal; A power divider for receiving a signal from the leakage signal canceller and dividing the signal into two identical signals; Two mixers for performing quadrature mixing using the LO signal from the interrupt coupler block and the signal from the power divider; And a baseband signal obtained by removing the transmission leakage signal. The radar apparatus of claim 1, further comprising a power amplifier between the signal generator and the front end coupler block, and a low noise amplifier between the leakage signal canceller and the mixer. 2. The radar device of claim 1, wherein said interrupt coupler block is any one selected from the group of quadrature couplers consisting of a directional coupler, a Lange coupler, and a branch line coupler. 2. The radar device of claim 1, wherein the shear coupler block comprises a termination resistor and any one selected from the group of quadrature couplers consisting of a directional coupler, a Lange coupler and a branch line coupler. 2. The radar device of claim 1, wherein the front coupler block is comprised of a power divider and a 90 degree phase shift block. The radar device according to claim 1, wherein the rear end coupler block is made of one of a quadrature coupler group consisting of a directional coupler, a Lange coupler and a branch line coupler and a termination resistor. The radar device according to claim 1, wherein the rear coupler block is formed of a combiner and a 90 degree phase shift block. 2. The radar device of claim 1, wherein said leakage signal canceller comprises any one selected from the group of quadrature couplers consisting of a directional coupler, a Lange coupler and a branch line coupler. 2. The radar device of claim 1, wherein said leak signal canceller comprises a combiner and a 90 degree phase shift block. 10. The radar device according to any one of claims 5, 7, and 9, wherein the combiner and the power divider each have a Wilkinson-type three-port structure. A signal generator; A front coupler block configured to output two signals having the same magnitude and 90 degrees out of phase from the signal generator; Two interrupted coupler blocks for receiving and transmitting a transmission signal from the front end coupler block and receiving a reception signal as well as generating an inevitable transmission leakage signal therein; Receives a 90-degree phase difference transmitted from the interrupted coupler block and transmits it without loss to the antenna and transmits the received signal from the antenna to the rear coupler block having the same magnitude and 90-degree phase difference to send to the interrupted coupler block ; A leakage signal canceller for removing the transmission leakage signal while adding up the reception signal; A mixer performing mixing using the LO signal from the signal generator and the signal from the leakage signal canceller; And a baseband signal obtained by removing the transmission leakage signal. 12. The radar apparatus of claim 11, further comprising a power amplifier between the signal generator and the front end coupler block and a low noise amplifier between the leakage signal canceller and the mixer. 12. The radar device of claim 11, wherein said interrupt coupler block is comprised of a termination resistor and one selected from the group of quadrature couplers consisting of a directional coupler, a Lange coupler and a branch line coupler. 12. The radar device of claim 11, wherein the shear coupler block is comprised of a termination resistor and one selected from the group of quadrature couplers consisting of a directional coupler, a Lange coupler and a branch line coupler. 12. The radar apparatus of claim 11, wherein the front coupler block is comprised of a power divider and a 90 degree phase shift block. 12. The radar device according to claim 11, wherein the rear end coupler block is made of any one selected from the group of quadrature couplers consisting of a directional coupler, a Lange coupler and a branch line coupler. 12. The radar device according to claim 11, wherein the rear end coupler block comprises a combiner and a 90 degree phase shift block. 12. The radar device of claim 11, wherein said leak signal canceller comprises any one selected from the group of quadrature couplers consisting of a directional coupler, a Lange coupler, and a branch line coupler. 12. The radar apparatus of claim 11, wherein the leak signal canceller comprises a combiner and a 90 degree phase shift block. 20. The radar device according to any one of claims 15, 17 and 19, wherein the combiner and the power divider each have a Wilkinson-type three-port structure.

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