KR101308083B1 - Frequency detector - Google Patents

Abstract

PURPOSE: A broadband frequency detector is provided to express information on all the radar signals to relative numerical values by detecting X-band frequencies, K-band frequencies, Ka-band frequencies, pulsed modulated radar frequencies, and FMCW radar frequencies with one frequency detector. CONSTITUTION: A broadband frequency detector comprises a horn antenna, a first amplifier, a mixing part, a second amplifier, and a signal detecting part. The horn antenna receives specific frequency signals. The first amplifier receives the specific frequency signals from the horn antenna. The mixing part receives the amplified signals from the first amplifier. The second amplifier is arranged in parallel to the first amplifier; amplifies the signals receiving from the horn antenna; and transmits the amplified signals to the mixing part. The signal detecting part receives the signals outputted from the mixing part and detects signals having under a preset wavelength from the received signals. The signal detecting part comprises a log detecting part (402), an amplifying part, and a comparator. The log detecting part detects the intensity of the signals receiving from the mixing part. The amplifying part amplifies voltage output according to the intensity of the signals detected by the log detecting part. The comparator receives the signals amplified by the amplifying part. [Reference numerals] (238) Central processing unit; (402) Log detecting part

Description

Wideband Frequency Detector {Frequency detector}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wideband frequency detector, and more particularly, to a frequency detector for detecting all signals for inducing safe driving of a vehicle and a radar signal for grasping the speed of the vehicle.

In developed countries, much effort has been made to ensure the safe operation of vehicles by using different types of speed meters using different microwaves and lasers, as well as pre-safety warning transmitters that signal various dangerous situations on the road. In particular, the United States legally recognizes the use of such speed meters and detectors.

The following signals are used depending on the type of signal used in these measuring devices and detectors.

In other words, speed gun (SPEED GUN) to detect the speed of the vehicle to prevent the speed of the vehicle is X-BAND (10.525 GHz), Ku-BAND (13.450 GHz), K-BAND (24.150 GHz), SUPERWIDE Ka-BAND (Various distributions between 33.000-38.000 GHz) and LASER (having a wavelength of 800 nm-1100 nm), and safety boundaries to inform road information for safe driving of vehicles. The SAFETY ALERT SYSTEM uses three frequencies from 24.070 to 24.230 GHz to transmit three pieces of information: railroad crossings, under construction, and emergency vehicles. The SAFETY WARNING SYSTEM uses fog from 24.075 to 24.125 GHz. 64 types of information such as area, under construction, school area and speed reduction are coded and transmitted. And in recent years, the movement to spread the installation of the Collision Avoidance System (CAS) as part of the vehicle safety system has been spreading around Europe. In the case of the collision avoidance system, various modulations have been made in the 24 GHz and 76 GHz bands. By using the method, interworking between collision avoidance systems and unnecessary signal interference are avoided.

Such safety-related transmission and reception systems have been active around the United States until now, and are spreading throughout Europe, including Germany, France, and Russia, as well as in some Asian countries such as Australia, Japan, and China. It is expected that the relationship to ITS will be large.

All of the above frequencies and uses are already defined by the Federal Communications Commission (FCC) in the United States.

1 illustrates a conventional broadband radar detector. Referring to FIG. 1, the broadband radar detector includes a horn antenna 10, a signal processor 20 for detecting a signal received by the horn antenna 10, a laser module 30 for receiving a laser signal, and the signal. A central processing unit 40 for controlling the detection of the signals in the processing unit 20 and the laser module 30, visual display means 50 for visually displaying the detected signals, and amplifying the detected signals. It is composed of a voice display means 60 to display the voice through the unit 61, the user receives a signal of nine bands of X, VG2, Ku, K, SA, SWS, SUPERWIDE Ka, and laser (laser) It is to help the user's safe operation by outputting the received signal in the best way according to the situation.

Receives the signal of more than 11 bands of X, VG2, SP1, SP-Elite, Ku, K, Modulated K, SA, SWS, SUPERWIDE KA, and laser to receive the received signal in an optimal way according to the user's situation It is to help the user to drive safely by outputting.

In addition, since the conventional broadband radar detector receives a frequency of 10 kHz to 38 kHz, it is possible to detect the frequencies of the X band, the K band, and the Ka band, but it is difficult to distinguish the high speed pulse modulation radar signal immediately. There is a vulnerability. So we added a separate Logarithmic Detector circuit (???) to detect the presence of a signal. However, even if such a high-speed pulse modulated radar signal is detected, there is still a problem in that the power strength of the high-speed pulse modulated signal cannot be properly interpreted unless an expensive MCU or a high-speed ADC with a high-speed ADC function is mounted. . Considering the recent increase in the collision avoidance system (CAS) and the increasing frequency of the use of the pulse modulation radar gun, the need for an automatic detection capability for these modulation signals is emerging.

An object of the present invention is to propose a broadband frequency detector.

Another object of the present invention is to propose a method of detecting a pulse modulated radar signal using a single frequency detector.

Another object of the present invention is to propose a frequency detector capable of simultaneously detecting pulse modulated radar signals while distinguishing X / K / KA band frequencies and distinguishing power levels of pulse modulated radar signals. have.

To this end, the wideband frequency detector of the present invention includes a horn antenna for receiving a signal having a specific broadband frequency, a first amplifier for receiving the signal having a specific frequency from the horn antenna, and a low noise amplified signal from the first amplifier. A mixer receiving from a first amplifier, disposed in parallel with the first amplifier, a second amplifier for low-noise amplifying the signal received from the horn antenna and delivered to the mixer, receiving the signal output from the mixer And a signal detector for detecting a signal having a wavelength less than or equal to a set wavelength from the received signal.

The broadband frequency detector according to the present invention detects not only the X band frequency, the K band frequency, the Ka band frequency but also the fast pulse modulated radar frequency and the frequency modulated frequency FMCW radar using one frequency detector. For all radar signals, the signal strength, that is, the power level of the radar signal, can be expressed as a relative numerical value through sound or display.

1 illustrates a conventional broadband radar detector.
2 is a block diagram illustrating a configuration of a broadband frequency detector according to an embodiment of the present invention.
3 is a view showing the configuration of a coupler according to an embodiment of the present invention.
4 is a diagram illustrating a configuration of a signal detector according to an embodiment of the present invention.
5 illustrates waveforms of voltages for controlling signals output from the first local oscillator according to an exemplary embodiment of the present invention.
6 is a waveform diagram of signals for controlling the second local oscillator and the third local oscillator;
7 is a control waveform diagram of a signal from a Log-Detector, a signal of a comparator, and a DAC signal for level control according to an embodiment of the present invention.

The foregoing and further aspects of the present invention will become more apparent through the preferred embodiments described with reference to the accompanying drawings. Hereinafter will be described in detail to enable those skilled in the art to easily understand and reproduce through this embodiment of the present invention.

2 is a block diagram illustrating a configuration of a broadband frequency detector according to an embodiment of the present invention. Hereinafter, a configuration of a broadband frequency detector according to an embodiment of the present invention will be described in detail with reference to FIG. 2.

The horn antenna 200 receives a signal having a specific frequency from the outside. As described above, the horn antenna 200 of the present invention receives a frequency having a wide bandwidth. In general, the frequency band received by the horn antenna 200 is 10 kHz to 38 kHz. The signal received by the horn antenna 200 is a first amplifier of MMIC (Monolithic Microwave Integrated Circuits) LNA (Low-noise amplifier) 202 and other specific frequency band It is delivered to the coupler 204, which passes relatively more than the frequency band. The MMIC LNA 202 is used to receive signals having a K band frequency band and a Ka band frequency band, and the coupler 204 is used to receive a signal having an X band frequency band.

The signal output from the MMIC LNA 202 and the coupler 204 is transferred to the first mixing unit 206. The first mixing unit 206 mixes a first intermediate frequency band in which a signal received from the MMIC LNA 202 and the coupler 204 and a signal received from the first low-noise amplifier 208 are mixed. It outputs a signal having a 1 GHz band. Although the MMIC LNA 202 and the coupler 204 are shown in FIG.

The first LNA 208 amplifies a signal having a specific frequency band generated by the first local oscillator 212 and transfers the signal to the first mixer 206.

The first local oscillator 212 controls (re-adjusts) the voltage to vary the frequency by the DAC sweep voltage waveform output from the sweep controller 214. The first local oscillator 212 generates a frequency by the readjusted voltage, and when the appropriate signal is received, as in the white noise, the sweep voltage is adjusted to generate a certain white noise pulse, and the mid / high frequency noise is removed.

The signal output from the first mixing unit 206 is transferred to the second LNA 210. The second LNA 210 low noise amplifies the received signal and transfers the received signal to the third LNA 218. The third LNA 218 low noise amplifies the received signal and transfers the received signal to the fourth LNA 220. The fourth LNA 220 low-noise amplifies the received signal and transfers the received signal to the second mixing unit 224 and the signal detector 222. Although FIG. 2 illustrates the second to fourth LNAs 220, the present invention is not limited thereto. That is, the number of LNAs may vary depending on the characteristics of the wideband frequency detector.

The second mixing unit 224 is already detected according to the band of the received signal among the oscillation frequencies of the second local oscillator 226 or the third local oscillator 228 designed to receive all the signals having the received wideband frequency. Convert the first intermediate frequency to the second intermediate frequency.

The second local oscillator 226 outputs a signal having a frequency of 550 MHz to 650 MHz by a pulse output from the central processing unit, and the third local oscillator 228 outputs a signal having a frequency of 1500 MHz to 2000 MHz. Rash. The signal output from the second mixing unit 224 is transferred to the second filter 230. The second filter 230 transmits only the 10 MHz signal from the received signal to the demodulator 232. The demodulator 232 detects the received signal and transfers it to the third filter 234 or the fourth filter 236. The third filter 234 passes a low frequency band signal for measuring RSSI from the received signal, and the fourth filter 236 passes the specific band signal of the received signal to the central processing unit 238.

In addition, the broadband frequency detector of the present invention displays the operation state of the detector, or other display unit 246 for displaying the necessary information, input unit 244 for inputting the necessary information, outputting the operating state of the detector or other necessary information to the audio output And a voice output unit 242. In addition, the wideband frequency detector includes a storage unit 240 for storing information necessary for driving the wideband frequency detector, or other necessary information.

3 shows a configuration of a coupler according to an embodiment of the present invention. Hereinafter, the configuration of the coupler according to an embodiment of the present invention will be described in detail with reference to FIG. 3.

Referring to FIG. 3, the coupler includes an input unit 300 having a bar shape receiving a signal received from a horn antenna and a filter unit 310 passing a signal of a specific frequency band among the signals input from the input unit 300.

The input unit 300 has a bar shape having a predetermined length. The filter unit 310 is positioned at an upper end of the bar-shaped input unit, and a portion having an 'N' shape and a left (or right) portion having an 'N' shape has a predetermined length and a portion of the bar shape having a '┌' shape. It is composed of a part having.

That is, the filter part 310 is composed of a first filter part 312 having an 'N' shape, a second filter part 314 having a bar shape, and a third filter part 316 having a '┌' shape. The second filter part 314 is formed at a predetermined distance from the upper end of the third filter part 316, and the first filter part 312 is located at the right side of the third filter part 316 and the second filter part 314. Is in close contact with the second filter portion 314 and the third filter portion 316. In addition, the height of the first filter part 312 (the longitudinal direction of the coupler shown in FIG. 3) coincides with the height of the second filter part 314 and the third filter part 316 which are spaced apart from each other. The width of the first filter part 312 (the transverse direction of the coupler shown in FIG. 3) is relatively smaller than the width of the second filter part 314 or the third filter part 316. In addition, the height of the bar-shaped part on the upper side of the part which comprises the height of the 2nd filter part 314 and the 3rd filter part 316 is the same.

4 is a diagram illustrating a configuration of the signal detector 222 according to an embodiment of the present invention. Hereinafter, the configuration of the signal detector according to an embodiment of the present invention will be described in detail with reference to FIG. 4.

According to FIG. 4, the signal detector includes an LNA, a log detector, an amplifier, a comparator, and an amplifier. Of course, other configurations other than the above-described configuration may be further included.

The signal output from the fourth LNA is input to the fifth LNA 400. The fifth LNA 400 low noise amplifies the input signal and outputs the amplified signal. The signal output from the fifth LNA 400 is input to the log detector 402. The log detector 402 detects the strength of the input signal and outputs the voltage.

The outline of the signal detected by the log detector 402 is transmitted to the amplifier 404 including the plurality of amplifiers 404-1 and 404-2. 4 illustrates an amplifier 404 including two amplifiers, but is not limited thereto. The amplifier 404 amplifies the input signal and delivers it to the comparator 406.

The comparator 406 compares the signal amplified by the amplifier 404 with the signal received from the central processing unit. Of course, the central processing unit 238 converts the digital signal into an analog signal and then inputs it to the comparator 406. The comparator 406 compares the signal amplified by the amplifier 404 with the signal output from the central processing unit 238, and outputs a comparison value. The output comparison value may know the difference between the signal amplified by the amplifier and the signal output from the CPU 238. The signal output from the comparator 406 is amplified by the amplifier 408 and then input to the central processing unit 238. The central processing unit analyzes the signal received from the amplifier 408 to determine whether the actual signal is detected or whether the detected signal is magnitude. That is, the size of the signal detected by adjusting the size of the signal input to the comparator from the central processing unit 238 can be known.

In addition, the signal detector of the present invention has an advantage of detecting a signal having a short wavelength output from the fifth LNA by using a relatively low cost comparator.

In the related art, when a pulsed modulated radar signal is received, only a signal type is determined to control the operation of the radar detector or inform the driver. Tended to get tired. However, in the case of processing in the above manner, the signal type determination and signal strength can also be measured so that it can be handled with proper operation. Removed in advance to allow more stable operation.

5 illustrates waveforms of voltages for controlling signals output from the first local oscillator according to an exemplary embodiment of the present invention. The maximum and minimum voltage values are set in advance through the tuning process and stored in memory. The present invention implements to detect a momentary pulsed Doppler signal by repeating a plurality of consecutive short sweeps (150 to 153) several times in order to increase the detection probability. The present invention adjusts the slope of the voltage (DAC voltage) output from the central processing unit to adjust the reception sensitivity for each frequency to be detected. Basically, the larger the slope, the lower the reception sensitivity, and if the slope is gentle, the reception sensitivity is improved. . This means that the DAC voltage is applied to the first local oscillator and mixed at the input frequency and the first mixer, where the performance time in this operation is related to sensitivity, which is controlled by the sweep slope.

Using this principle, the slope of the sweep is smoothed in the frequency range (frequency ranges except 33.8 kHz, 34.7 kHz, and 24.150 kHz) where the sensitivity of motion should be set to the maximum while maintaining the normal operation response speed.

In addition, even if the sensitivity is slightly reduced, the frequency of the short signal can be applied, while the sweep slope is performed slightly sharply, while repeatedly sweeping the frequency region sufficiently satisfying the frequency, the frequency reception rate is increased.

6 is a waveform diagram of signals for controlling the second local oscillator and the third local oscillator; 6, the signal for controlling the second local oscillator or the third local oscillator controls a frequency mixed with the first intermediate frequency and has a built-in flash memory as a program memory inside the central processing unit to select each local oscillation frequency. Stored in memory.

7 is a control waveform diagram of a signal from a log detector, a signal of a comparator, and a DAC signal for level control according to an embodiment of the present invention. According to Figure 7,

The process of finding the actual signal strength by changing the DAC level according to the intensity of the pulse modulated signal can be seen as a waveform. The change in the DAC level is implemented to maintain a stable level by applying hysteresis (hysteresis) timing in order to be insensitive to the change in the radar signal strength that changes instantly. In other words, even when generating pulse-modulated radar signal of constant power level, due to loss in air and H / W sensitivity deviation between radar gun and radar receiver, actual signal may be uneven at every moment. If the detector responds sensitively, the driver may feel uncomfortable, so the central processor controls the DAC level change by applying hysteresis timing.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the scope of the present invention .

200: horn antenna 202: MMIC LNA
204: pHEMT LNA 206: first mixing portion
208: first LNA 210: second LNA
212: first local oscillator 214: sweep control unit
216: switch control unit 222: signal detection unit

Claims (4)

A horn antenna for receiving a signal having a specific frequency;
A first amplifier receiving the signal having a specific frequency from the horn antenna;
A mixing unit configured to receive the low noise amplified signal from the first amplifier from the first amplifier;
A second amplifier disposed in parallel with the first amplifier and configured to low noise amplify the signal received from the horn antenna and to transfer the signal to the mixer;
And a signal detector for receiving a signal output from the mixer and detecting a signal having a wavelength less than or equal to a set wavelength from the received signal.
The method of claim 1, wherein the signal detection unit,
A log detector for detecting the strength of the signal received from the mixer;
An amplifier for amplifying a voltage output for the strength of the signal detected by the log detector;
And a comparator receiving the signal amplified by the amplifier.
The method of claim 2, wherein the comparator,
Receives a signal having a set size from an external processing device,
And compares the magnitude of the signal input from the external processing device with the signal input from the amplifier and outputs a comparison value.
The wideband frequency detector of claim 3, wherein a magnitude of a signal output from the external processing device is variable.

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