JP2007208634A - Radar transmitter-receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radar transmitter-receiver that can be made compact. <P>SOLUTION: The radar transmitter-receiver is provided with: a crystal oscillator that oscillates in a prescribed frequency; a frequency divider for performing frequency division of an output of the crystal oscillator; a transmitting part for outputting a radar signal; a switching power supply for feeding current to the transmitting part; a receiving part for receiving a reflected wave to the radar signal outputted from a transmitting circuit; and a control power supply part for feeding current to the receiving part, and sets a fundamental frequency of switching of the switching power supply and a receiving band of the receiving part so that the receiving band of the receiving part may be placed between an n-th harmonic frequency of the fundamental frequency of switching in the switching power supply and an (n+1)-th harmonic frequency. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a radar transmission / reception apparatus, and more particularly to a radar transmission / reception apparatus using a switching power supply as a transmission power supply.

  In order to reduce the size of the radar transmitter / receiver, it is necessary to pack a high-power transmitter and a high-accuracy receiver in a limited space. While a high-power transmitter requires a power source for flowing a large current, it is also necessary to suppress noise generated by the power source in order to improve the reception sensitivity of the apparatus.

In order to solve this problem, conventionally, it has been necessary to suppress the noise of the transmission power supply by the output filter of the power supply circuit or to insert a bandpass filter for limiting the reception band (see Patent Documents 1 to 3). ). However, if this is done, there is a problem that the radar transmitting / receiving apparatus becomes large.
JP 2003-133972 A JP-A-11-332230 Japanese Patent No. 268486

  The present invention has been made in view of the above-mentioned conventional problems, and even when a switching power supply is used as a transmission power supply, a large filter is not required to suppress the generated noise, and the downsizing can be achieved. An object of the present invention is to provide a radar transmission / reception device that can be used.

  According to claim 1 of the present invention, a crystal oscillator that oscillates at a predetermined frequency, a frequency divider that divides the output of the crystal oscillator, a transmitter that outputs a radar signal, and a current that is supplied to the transmitter A switching power supply, a receiving unit that receives a reflected wave with respect to the radar signal output from the transmission circuit, and a control power supply unit that supplies current to the receiving unit, and the reception band of the receiving unit is the switching power supply The switching fundamental frequency of the switching power supply and the reception band of the receiving unit are set so as to fall between the nth harmonic frequency (n; positive integer) and the n + 1st harmonic frequency of the fundamental frequency of switching in A radar transmitting / receiving apparatus is provided.

  According to the present invention, it is possible to bring a transmission system and a reception system close to each other, and there is an effect that a radar transmission / reception apparatus that can be downsized is obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an example of the overall configuration of an embodiment of the present invention. The radar transmitting / receiving apparatus includes a transmitter 11 that transmits a radar signal, a driver 12 of the transmitter, a receiver 13 that receives a radar signal, a reception amplifier 14 that amplifies the received signal, and a driver. 12, a transmission / reception processing unit 15 for processing a reception signal amplified by the reception amplification unit 14, a transmission power supply unit 16a for supplying a constant voltage current to the transmission unit 11 and the drive unit 12, A control power supply unit 16b that supplies current to the reception unit 13 and the reception amplification unit 14, a crystal oscillator 17, and an oscillation output of the crystal oscillator 17 are input to perform predetermined frequency division, and the transmission power supply unit 16a performs frequency division. A frequency dividing circuit 18a for supplying an output, and a frequency dividing circuit 18b for receiving the oscillation output of the crystal oscillator 17 and performing a predetermined frequency division and supplying a frequency divided output to the control power supply unit 16b. In the transmission / reception processing unit 15, the reception signal amplified by the reception unit is electrically processed for display or for performing predetermined arithmetic processing.

  The transmission power supply unit 16a receives a reference signal generation circuit 21a that receives the output of the frequency dividing circuit 18a as an input, generates a reference signal, an error amplifier 22a that uses the output of the reference signal generation circuit 21a as one input, and an input power supply. A switching circuit 23a that switches the supplied current, a drive circuit 24a that receives the output of the error amplifier 22a and drives each element of the switching circuit 23a, and an output of the switching circuit 23a that receives the output of the constant voltage. The filter circuit 25a is supplied to the transmission unit 11 and the drive unit 12 and is fed back to the error amplifier 22a as the other input. For example, an 8V output switching power supply is configured.

  The control power supply unit 16b is supplied from an input power supply, a reference signal generation circuit 21b that receives the output of the frequency dividing circuit 18b and generates a reference signal, an error amplifier 22b that uses the output of the reference signal generation circuit 21b as one input, and the like. A switching circuit 23b for switching the current to be supplied, a drive circuit 24b for receiving the output of the error amplifier 22b and driving each element of the switching circuit 23b, and the output of the switching circuit 23b. The filter circuit 25b is supplied to the amplifying unit 14 and fed back to the error amplifier 22b as the other input. For example, a switching power supply of 5V output is configured.

  If the oscillation frequency of the crystal oscillator 17 is, for example, 1.2 MHz, and the frequency dividing circuit 18a is, for example, a divide-by-4 circuit, the frequency-divided output is 300 kHz. The signal is supplied to a reference signal generation circuit 21a composed of a triangular wave generation circuit.

  On the other hand, the switching circuit 23a is, for example, a forward type converter, and the switching control of the switching circuit 23a is driven and controlled by a drive circuit 24a that is a drive transformer. The output of the reference signal generation circuit 21a is supplied as one input signal to an error amplifier 22a composed of, for example, an operational amplifier. The output of the switching circuit 23a is fed back to the error amplifier 22a through the filter circuit 25a as the other input signal, and the error signal is sent to the drive circuit 24a as the output of the error amplifier 22a.

  If the frequency divider 18b is, for example, a frequency divider of 2, the output is 600 kHz, and a signal of this frequency is input to the reference signal generating circuit 21b of the control power supply unit 16b. In the control power supply unit 16b, the reference signal generation circuit 21b is constituted by, for example, a triangular wave generation circuit, the error amplifier 22b is constituted by, for example, an operational amplifier, the switching circuit 23b is a forward type converter, and the drive circuit 24b is, for example, a drive transformer or It is composed of an FET driver.

  As described above, the control power supply unit 16b has the same configuration as the transmission power supply unit 16a, but in order to obtain a high output from the transmission unit 11, the transmission power supply unit 16a is designed to flow a large current. In addition, noise generated in the switching power supply that is the transmission power supply unit 16 a may affect the reception unit 13.

  However, in this embodiment of the present invention, as will be described next with reference to FIG. 2, by setting the reception bandwidth of the reception unit 13 that receives the frequency-modulated signal to be in a predetermined frequency range. It is possible to remove and suppress the influence of switching noise generated in the transmission power supply unit 16a.

  Now, as indicated by F in FIG. 2, the fundamental frequency of switching of the transmission power supply unit 16a is 300 kHz, and the center frequency of the reception band of the reception unit 13 is around 10 MHz. In FIG. 2, the horizontal axis represents frequency and the vertical axis represents strength.

  At this time, since 10000/300 = 33.33, 300 kHz × 33 = 9.9 MHz (shown as S33 in FIG. 2) and 300 kHz × 34 = 10.2 MHz (shown as S34 in FIG. 2). Therefore, the reception band of the receiving unit 10 may be set with 9.9+ (10.2−9.9) /2=10.05 MHz as the center frequency. In this case, the reception band of the reception unit 13 is 0.3 MHz at the maximum, but it is not usually necessary to have such a wide band in radar reception, and a band narrower than this can be set as the reception band BW.

  When the center frequency and the reception band of the radar reception are determined in advance, the oscillation frequency of the crystal oscillator 17 and the basic frequency of the switching power source of the transmission power supply unit are determined accordingly, and the reception band of the reception unit 10 is determined. In consideration of the above, the reception band may be determined so as to fall between the n-th harmonic frequency and the n + 1-order harmonic frequency of the fundamental frequency.

  At that time, the frequency dividing ratio of the frequency dividing circuit that divides the output of the crystal oscillator is appropriately set according to the oscillation frequency of the crystal oscillator and the fundamental frequency of the transmission power supply unit.

  According to the above embodiment of the present invention, since the output of the crystal oscillator is divided and supplied to the transmission power supply unit and the control power supply unit, the frequency hardly fluctuates even if the temperature rises. There is an advantage that the reception band can be avoided.

  In the above embodiment, the case where the control power supply of the reception system is also configured by the switching power supply has been described, but the control power supply does not necessarily have to be configured by the switching power supply.

  The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the technical idea of the present invention.

1 is a diagram illustrating an overall configuration of a radar receiver according to an embodiment of the present invention. The figure for demonstrating the frequency relationship in one Embodiment of this invention.

Explanation of symbols

11: Transmitter,
12 ... Drive unit,
13 ... receiving part,
14: Reception amplification unit,
15 ... transmission / reception processing unit,
16a: power supply unit for transmission,
16b ... Control power supply unit,
17 ... Crystal oscillator,
18a, 18b ... frequency divider,
21a, 21b... Reference signal generation circuit,
22a, 22b ... error amplifier,
23a, 23b... Switching circuit,
24a, 24b... Drive circuit,
25a, 25b... Filter circuit.

Claims (4)

A crystal oscillator that oscillates at a predetermined frequency;
A frequency divider that divides the output of this crystal oscillator;
A transmitter for outputting a radar signal;
A switching power supply for supplying current to the transmitter;
A receiving unit that receives a reflected wave with respect to a radar signal output from the transmission circuit;
A control power supply for supplying current to the receiver,
The fundamental frequency of switching of the switching power supply and the frequency of the switching power supply so that the reception band of the receiver falls between the nth harmonic frequency (n; positive integer) of the fundamental frequency of switching in the switching power supply and the n + 1st harmonic frequency. A radar transmission / reception apparatus characterized by setting a reception band of a reception unit.   The radar transmission / reception apparatus according to claim 1, wherein the control power supply unit includes a switching power supply. A transmitter for outputting a radar signal;
A receiving unit for receiving a reflected wave with respect to the radar signal transmitted from the transmitting unit;
A crystal oscillator that oscillates at a predetermined frequency;
A first frequency divider that divides the output of the crystal oscillator;
A power supply unit for transmission configured by a switching power supply, which is supplied with an output of the first frequency divider and supplies current to the transmitter;
A second frequency divider that divides the output of the crystal oscillator;
A control power supply unit that receives the output of the second frequency dividing circuit and supplies current to the receiving unit;
The switching power supply is configured so that the reception band of the receiving unit is between the nth harmonic frequency (n; positive integer) of the fundamental frequency of switching in the switching power supply of the transmission power supply unit and the n + 1st harmonic frequency. A radar transmission / reception apparatus characterized by setting a fundamental frequency of switching and a reception band of the reception unit.   The radar transmission / reception apparatus according to claim 3, wherein the control power supply unit includes a switching power supply.

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