KR100687907B1 - Radar detector using SMM Self-Multiplier Mixer - Google Patents

Abstract

The present invention relates to a radar detector, and more particularly, in the X-band (10.525 ± 0.05 GHz), K-band (24.150 ± 0.125 GHz), Ka-band (34.7 GHz ± 0.3 GHz) The present invention relates to a radar detector using a new self-multiplier mixer (SMM) circuit to improve sensitivity performance.

Conventionally, a single local oscillator is used to detect multi-band signals in the X-band (10.525 ± 0.05 GHz), K-band (24.150 ± 0.125 GHz) and Ka-band (34.7 GHz ± 1.3 GHz) input through an antenna. Although multiband signals have been detected by using the present invention, the reception performance of the K-band and Ka-band has been degraded. To solve these problems, two or three secondary local oscillators used in RF module 120 or primary local oscillators used in microwave module 110 are K-band (24.150 ± 0.125 GHz). There are two methods for detecting the Ka-band (34.7 GHz ± 1.3 GHz) and the first mixer part of the microwave module using the anti-parallel (AP) beam lead diode. It had many problems with high price and productive aspects.

Therefore, in the present invention, by varying the bias voltage applied to the passive element and the active element having the nonlinear characteristic, the amplitudes of the signals f _LO , 2f _LO , and 3f _LO are selectively maximized, and thus the sum of the two input signals f _IN and f _LO and Self-Multiplier Mixer (SMM) circuits to selectively maximize the output signal components (| f _IN ± f _LO |, | f _{IN ±} 2f _LO |, | f _IN ± 3f _LO |) corresponding to the difference (Radar Detector) to convert X-band (10.525 ± 0.05 GHz), K-band (24.150 ± 0.125 GHz) and Ka-band (34.7 GHz ± 0.3 GHz) frequencies corresponding to f _IN signals into low frequency signals It aims to improve radar detector reception sensitivity performance in X-band, K-band and Ka-band by minimizing the conversion loss that occurs during the process.

Self-Multiplier Mixer, Multi-Function, Variable Bias

Description

Radar detector using SMM (Self-Multiplier Mixer) circuit {Radar detector using SMM (Self-Multiplier Mixer)}             

1A and 1B are exemplary views for explaining a general radar detector product.

2A, 2B and 2C are exemplary views for explaining a method for improving a conventional sensitivity characteristic.

Figure 3 is an exemplary view for explaining the radar detector (Radar Detector) proposed in the present invention.

4 is an exemplary diagram for explaining characteristics of output harmonic current components according to a bias change applied to nonlinear devices.

FIG. 5 is an exemplary diagram for explaining a change in magnitude of frequency components shown at an output side by two input signals according to a bias change applied to nonlinear elements; FIG.

6 is an exemplary diagram for explaining the operation principle when the SMM (Self-Multiplier Mixer) circuit proposed in the present invention is applied to a radar detector.

7 is an exemplary diagram for explaining the operation principle when a self-multiplier mixer (SMM) circuit implemented using an active element is applied to a radar detector.

8A, 8B, and 8C are exemplary views for explaining conversion loss characteristics of a radar detector to which a self-multiplier mixer (SMM) circuit of the present invention is applied.

<Explanation of symbols for the main parts of the drawings>

  110: microwave module 111: antenna unit

  112: primary mixer 113, 116 primary local oscillator

  115: variable bias 117: SMM

  120: RF module 121: amplifier

  122: secondary mixer portion 123: filter portion

  124: secondary local oscillator 130: baseband module

  131: demodulation unit 132: signal processing control unit

The present invention applies a new self-multiplier mixer (SMM) to a radar detector, and a radar detector designed to derive an improved sensitivity performance than a conventional radar detector along with a low-cost product implementation. It is about.

Radar Detector is a system that detects laser or microwave signals shot by a speed gun to measure the speed of a moving vehicle and informs the driver through beeps, voices, and texts. Various products using (10.525 ± 0.05 GHz), K-band (24.150 ± 0.125 GHz), Ka-band (34.7 GHz ± 0.3 GHz) signals or lasers have been developed and used for safe driving of vehicles. .

The radar detector for this purpose is the X-band (10.525 ± 0.05 GHz), K-band (24.150 ± 0.125 GHz), Ka-band (34.7 GHz ± 0.3 GHz) frequencies belonging to the ultra-high frequency region as shown in FIG. 1A. The microwave module 110 converts the signal into a low frequency (1.0 GHz) signal, the RF module 120 converts a frequency signal of about 1.0 GHz into an IF frequency (10.7 MHz) signal, and demodulates the converted IF frequency. It consists of a baseband module (130) for providing a detailed description as follows.

As shown in Figure 1a and the antenna unit 111 for receiving an ultra-high frequency signal; A primary local oscillator 113 for generating a specific frequency in the mixer circuit; The X-band (10.525 ± 0.05 GHz), K-band (24.150 ± 0.125 GHz) and Ka-band (34.7 GHz ± 0.3 GHz) signals received from the antenna unit are mixed with the frequencies generated by the primary local oscillator. A primary mixer 112 for converting into a low frequency (1.0 GHz) signal; An amplifier 121 for amplifying the low frequency (1.0 GHz) signal converted by the primary mixer; A secondary mixer unit 122 for converting the amplified low frequency (1.0 GHz) signal to the IF frequency (10.7 MHz); A secondary local oscillator 124 for generating a frequency signal required for the secondary mixer 122; A secondary filter unit 123 for obtaining only a specific band signal of an IF frequency (10.7 MHz) signal among the output signals converted by the secondary mixer unit 122; A demodulator 131 for A / D converting an IF frequency (10.7 MHz) signal filtered to a specific band through the filter unit 123; The signal processing controller 132 is configured to receive and process the demodulated signal and to perform appropriate control of each component. A laser detection circuit for detecting a laser may be added to the configuration.

FIG. 1B shows the characteristics of the output frequency components of the primary local oscillator 113 generated by the same method as in FIG. 1A. Since the signal level of 2f _LO and 3f _LO input to the primary mixer 112 is small to convert to frequency (1.0 GHz) signal, K-band (24.150 ± 0.125 GHz) and Ka-band (34.7 GHz ± 0.3 GHz ) When the frequency is converted to a low frequency (1.0 GHz) signal, the signal loss is large, so the sensitivity performance of the radar detector is degraded.

Several methods have been proposed to improve sensitivity performance in the X-band (10.525 ± 0.05 GHz), K-band (24.150 ± 0.125 GHz) and Ka-band (34.7 GHz ± 0.3 GHz).

The method of using two or three secondary local oscillators 124 used in the RF module 120 as shown in FIG. 2A has a disadvantage in that the sensitivity performance is not improved because the characteristics of the microwave module 110 are not good. .

FIG. 2B illustrates a method of configuring two primary local oscillators 113 used in the microwave module 110 for K-band (24.150 ± 0.125 GHz) and Ka-band (34.7 GHz ± 0.3 GHz) frequency conversion. However, due to the high output frequency and signal level of the primary local oscillator 113, parts cost is high, the reliability of the circuit is lowered, and the size of the product increases.

FIG. 2C illustrates a method of using the first mixer unit 112 of the microwave module 110 using an anti-parallel (AP) beam lead diode. However, since the component price is high and a small component size of 0.5 mm or less, There is a disadvantage in that productivity is reduced because very expensive special equipment is required.

In order to solve the above problems, the present invention selectively maximizes the amplitude of the f _LO , 2f _LO , and 3f _LO signals by varying the bias voltage applied to the passive element and the active element having nonlinear characteristics, thereby providing two input signals f _IN. and outputs the signal component corresponding to the sum and the difference of _{f LO) (| f iN ±} f LO |, | f iN ± 2f LO |, | f iN ± 3f LO |) selectively capable of maximizing SMM (Self- the By applying the Multiplier Mixer (117) circuit to the radar detector, the X-band (10.525 ± 0.05 GHz), K-band (24.150 ± 0.125 GHz), and Ka-band (34.7 GHz ±) corresponding to the f _IN signal. When converting 0.3 GHz) frequency signal to low frequency (1.0 GHz) signal, the conversion loss characteristics are minimized, which improves the radar detector reception sensitivity in the X-band, K-band, and Ka-band, and also lowers the cost. And stable product production.

3, the X-band (10.525 ± 0.05 GHz), K-band (24.150 ± 0.125 GHz), Ka-band (34.7 GHz ± 0.3 GHz) signal corresponding to the f _IN signal is shown in FIG. An antenna unit 111 for receiving the sound; A self-multiplier mixer (SMM) unit 117 implemented as an SMD (Surface Mount Device) type device; A primary local oscillator 116 for generating a frequency signal necessary for the operation of the SMM; The variable bias unit 115 capable of varying the bias voltage is configured.

When a single frequency (f _LO ) is applied to a device with nonlinear characteristics, such as a passive element (Varactor, Schottky, SRD diode) or an active element (BJT, FET, MOS), the non-linear element causes a single frequency (f _IN ). The frequency component-harmonics (2f _LO , 3f _LO , 4f _LO ... etc) and the input single frequency (f _LO ) components corresponding to integer multiples of are shown on the output side.

Figure 4a shows that the current magnitude of the harmonic signals output from the nonlinear active element changes according to the conduction angle, which is a harmonic component generated at the output stage by the nonlinear characteristics of the passive element and the active element according to the applied bias condition. Means that you can adjust the amplitude of (2f _LO , 3f _LO , 4f _LO ... etc). Where N represents the component of the Nth harmonic current.

4B is a diagram for explaining the above principle from another viewpoint. Circuits that operate on the same principle as above are generally called multipliers.

When two different signals are inputted to a device 114 having a nonlinear characteristic of a passive device or an active device, the output side can generate frequency components corresponding to the sum and difference of the two input signals. Named a Mixer.

FIG. 5 shows a structure in which another input signal f _IN is input to the structure of FIG. 4a, and the sum and difference of two input signals f _IN and f _LO at the output side of an active or passive element 114 having a nonlinear characteristic. The output signal components (| f _IN ± f _LO |, | f _IN ± 2f _LO |, | f _IN ± 3f _LO | ..etc) corresponding to the schematic diagram can be obtained. It can be seen that it is proportional to the signal sizes of f _LO , 2f _LO , and 3f _LO .

In the present invention, by varying the bias voltage applied to the passive element and the active element 114 having a nonlinear characteristic, the amplitudes of the f _LO , 2f _LO , and 3f _LO signals are selectively maximized to determine the two input signals f _IN and f _LO . The output signal components corresponding to the sum and difference (| f _IN ± f _LO |, | f _IN ± 2f _LO |, | f _IN ± 3f _LO |) can be selectively maximized.

In the same principle as described above, a passive element and an active element having a nonlinear characteristic may be implemented as a circuit having a multiplier and a mixer (Mixer) characteristic at the same time, which is referred to as a self-multiplier mixer (SMM) 117 in the present invention. .

In the present invention, by applying a self-multiplier mixer (SMM) circuit to the radar detector (X-band (10.525 ± 0.05 GHz), K-band (24.150 ± 0.125 GHz) than the method proposed in the prior invention In the Ka-band (34.7 GHz ± 0.3 GHz), a radar detector with high sensitivity, low cost and high productivity can be commercialized.

In order to explain the effect of the present invention, the output frequency f _LO of the local oscillator 116 is fixed at 11.558 GHz and the X-band (10.525 GHz), K- corresponding to the f _IN signal through the antenna unit 111. When the band (24.150 GHz) and Ka-band (33.64 GHz) frequencies are input, the | f _IN ± f _LO | Or | 10.525 GHz ± 11.558 GHz | = 1.033 GHz frequency component with maximum value and | f _IN ± 2f _LO | Or | 24.250 GHz ± 2 (11.558) GHz | = 1.034 GHz frequency component with maximum value and | f _IN ± 3f _LO | Or | 33.64 GHz ± 3 (11.558) GHz | = 1.034 GHz frequency components have maximum values.

FIG. 6 is a diagram for explaining the above contents, and FIG. 7 is a diagram for explaining the configuration and operation principle of a simplified self-multiplier mixer (SMM) circuit 117 using an active element having a nonlinear characteristic.

8A, 8B, and 8C show bias voltage values when the X-band (10.525 GHz), K-band (24.150 GHz), Ka-band (33.64 GHz) frequencies are input into a self-multiplier mixer (SMM) circuit. 8A shows conversion loss values for the X-band (10.525 GHz) and 8B shows the K-band (24.150 GHz) and 8C Ka-band (33.64 GHz). .

As described above, by varying the bias voltage applied to the passive element and the active element having nonlinear characteristics, the two input signals f _IN and f _LO are selectively maximized by maximizing the amplitude of the f _LO , 2f _LO , and 3f _LO signals. Self-Multiplier Mixer (SMM) circuit that can selectively maximize the output signal components (| f _IN ± f _LO |, | f _IN ± 2f _LO |, | f _IN ± 3f _LO |) corresponding to the sum and difference Can be applied to the radar detector to improve the product reception sensitivity more effectively than the conventional method, and to reduce the price of the product by allowing the use of general-purpose parts that can be used at low frequencies. There is an effect that can solve the problem of productivity that may occur.

Claims (3)

Radar detector for the detection of high frequency signal components such as X-band (10.525 ± 0.05 GHz), K-band (24.150 ± 0.125 GHz), Ka-band (34.7 GHz ± 0.3 GHz) An antenna unit 111 for receiving the high frequency signals from the module 110; By varying the bias voltage applied to the passive and active devices having nonlinear characteristics, the amplitudes of the signals f _LO , 2f _LO , and 3f _LO are selectively maximized to correspond to the sum and difference of the two input signals f _RF and f _LO . Self-implemented SMM (Surface Mount Device) type device that can selectively maximize output signal components (| f _RF ± f _LO |, | f _RF ± 2f _LO |, | f _RF ± 3f _LO |) A multiplier mixer section 117; A primary local oscillator 116 for generating a frequency signal necessary for the operation of the SMM; Radar detector, characterized in that it comprises a variable bias unit 115 that can vary the bias voltage. delete The device of claim 1, wherein the passive device includes a device having nonlinear characteristics in addition to a PN junction, a Varactor, a Schottky, and an SRD diode, and the active device includes a transistor having a BJT, FET, MOS transistor, and a nonlinear characteristic. Radar detector, characterized in that.

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