CN103439686A - Single-channel radio direction finding system - Google Patents

Abstract

The invention discloses a single-channel radio direction finding system. The single-channel radio direction finding system comprises an antenna array, a single-pole double-throw radio frequency switch module, a radio frequency receiving channel, a spectral analysis module, a control module and an output display module, wherein the antenna array is connected with the single-pole double-throw radio frequency switch module, the single-pole double-throw radio frequency switch module is connected with the radio frequency receiving channel, the radio frequency receiving channel is connected with the spectral analysis module, the spectral analysis module is connected with the control module, and the control module is connected with the single-pole double-throw radio frequency switch module and the output display module. The single-channel radio direction finding system is used for solving the problem of radio direction finding in the communication application, the military application and the like, the antenna array which is controlled by a high-speed radio frequency switch and carries out periodic switching is adopted, and measurement of the radio incident direction is achieved through analysis of frequency spectrum components of a received radio signal. The single-channel radio direction finding system is applicable to rapid radio direction finding needing low hardware complexity and low cost.

Description

The single channel radio direction-finding system

Technical field

The present invention relates to the antenna works technical field, specifically a kind of single channel radio direction-finding system of utilizing injection frequency passage to realize radio direction finding (RDF).

Background technology

Traditional radio direction finding (RDF) technology generally is comprised of several parts such as aerial array, multichannel receiver and controller, output display modules, such as phase-interferometer, direction finding array based on the super-resolution Estimation of Spatial Spectrum etc.With respect to the single channel direction-finding system, there is the hardware configuration complexity in the direction-finding system of many radio-frequency channels, and the high in cost of production shortcoming requires the amplitude-phase consistency of each radio-frequency channel better simultaneously, needs the outer calibration equipment of plus.Chinese patent " a kind of single channel radiolocation direction-finding system and direction-finding method thereof " (number of patent application: proposed a kind of single channel direction-finding method 201010598996.2), utilize switch to switch between the antenna element of circle distribution, carry out direction finding by the phase relation that compares the radio signal received on adjacent antenna units, but this direction-finding method requires only to have a radio signal incident within a direction finding cycle.When the incident simultaneously of a plurality of radio signals, cause the phase relation confusion obtained, thereby cause the direction finding failure.

Summary of the invention

The present invention is directed to above shortcomings in prior art, a kind of single channel radio direction-finding system be provided, this system adopt injection Quick Measuring that passage completes radio signal frequently to.

The present invention is achieved by the following technical solutions.

A kind of single channel radio direction-finding system, comprise aerial array 1, single-pole double throw RF switch module 2, receiving RF channel, spectrum analysis module 8, control module 9 and output display module 10, described aerial array 1 is connected with single-pole double throw RF switch module 2, described single-pole double throw RF switch module 2 is connected with receiving RF channel, described receiving RF channel is connected with spectrum analysis module 8, described spectrum analysis module 8 is connected with control module 9, described control module 9 is connected with output display module 10 with single-pole double throw RF switch module 2 respectively, wherein:

-aerial array, for receiving the radio signal of incident;

-single-pole double throw RF switch module, for the radio signal of periodically selecting aerial array to receive, and the feed-in receiving RF channel;

-receiving RF channel, carry out the radio signal of reception low noise amplification, downconvert to intermediate-freuqncy signal and suppress the high fdrequency component produced, and obtains analog if signal, then analog if signal is converted to digital signal;

-spectrum analysis module is estimated the fundamental component frequency spectrum of the digital signal exported on receiving RF channel and the frequency spectrum of harmonic component for the first time produced by the single-pole double throw RF switch module in numeric field;

-control module, control the periodicity of single-pole double throw RF switch module and open and turn-off by output logic signal; By relatively fundamental component and the relativeness of the frequency spectrum of harmonic component for the first time, obtain the radio incident direction;

-output display module, control module by the radio incident direction information output that obtains to display module and show.

Preferably, when described aerial array carries out the one dimension direction finding, adopt two antenna elements.

Preferably, described single-pole double throw RF switch module is single-pole double throw RF switch or is the combination of power splitter and single-pole single-throw switch (SPST).

Preferably, described single-pole double throw RF switch module is carried out periodic samples, and the radio signal of feed-in receiving RF channel not only comprises the original signal spectrum composition, also comprises with switching frequency f _peach harmonic component for the cycle generation.

Preferably, the switching frequency f of described single-pole double throw RF switch module _pand meet following relation between the bandwidth B of receiving RF channel:

f _p＞2B。

Preferably, described receiving RF channel is injection receiving cable frequently, comprise low noise amplifier 3, local oscillation signal generation module 4, down conversion module 5, low-pass filtering module 6 and analog-to-digital conversion module 7, wherein, described low noise amplifier 3 is connected with single-pole double throw RF switch module 2, described down conversion module 5 is connected with low-pass filtering module 6 with low noise amplifier 3, local oscillation signal generation module 4 respectively, described low-pass filtering module 6 is connected with analog-to-digital conversion module 7, described analog-to-digital conversion module 7 is connected with spectrum analysis module 8, wherein:

-low noise amplifier 3, carry out low noise amplification for the radio signal to receiving;

-local oscillation signal generation module 4, the required local oscillation signal for generation of down coversion;

-down conversion module 5, downconvert to intermediate-freuqncy signal for the radio signal by receiving;

-low-pass filtering module 6, carry out low-pass filtering for the signal to after down coversion, the high fdrequency component that filtering produces after down conversion module;

-analog-to-digital conversion module 7, be converted to digital signal by the analog intermediate frequency signal obtained.

Preferably, described spectrum analysis module is by spectrum estimation special chip, DSP chip (DSP) or programmable logic chip (CPLD, FPGA) and utilize discrete Fourier transformation (DFT) or Fast Fourier Transform (FFT) (FFT) method is estimated.

Preferably, described control module realizes the control to the single-pole double throw RF switch module by single-chip microcomputer, digital signal processor (DSP) or programmable logic chip (CPLD, FPGA).

Preferably, described control module obtains the method for radio incident direction, is specially:

By analysis and comparison fundamental component frequency spectrum Γ ₀with harmonic component frequency spectrum Γ for the first time ₁between relation, obtain radio incident direction θ, concrete calculated relationship is as follows:

$\mathrm{\θ}=-\arcsin \left(\frac{\mathrm{\λ}}{\mathrm{\πD}}\arctan \frac{\mathrm{\π}{\mathrm{\Γ}}_1}{2{\mathrm{\Γ}}_0}\right)$

Wherein, λ is the wavelength value corresponding for fundamental component, and D is the distance between antenna element; When the signal of incident is broadband rf signal, can select the fundamental component of some frequencies and harmonic component for the first time to compare, each frequency place is estimated to the angle information obtained averages as the incident direction of broadband rf signal.

Single channel radio direction-finding system provided by the invention, its course of work is: by control module output control signal, control single-pole double throw RF switch and periodically connect two antenna elements.The radio signal received on two antenna elements is by single-pole double throw RF switch timesharing feed-in low noise amplification module, after low noise amplification, the radiofrequency signal received is converted to intermediate frequency by down conversion module, and suppresses the high fdrequency component wherein produced by low-pass filtering.Utilize analog-to-digital conversion module that the analog if signal of output is converted to digital signal, then estimated by spectrum analysis module frequency spectrum of fundamental component to received signal and the harmonic component for the first time that produced by switch in numeric field.In control module, by relatively fundamental component and the relativeness of the frequency spectrum of harmonic component for the first time, obtain the direction of the radio signal of incident.Last control module will estimate that the incident direction obtained exports display module to and shows.

When control signal is 1, single-pole double throw RF switch is got to an end, and when control signal is 0, single-pole double throw RF switch is got to the other end.As can be seen from Figure 3, when switching over, the signal of the wireless signal received is undergone mutation.The Sudden Changing Rate of phase place is relevant with the incident direction of wireless signal, and is reflected in the frequency spectrum of single-pole double throw RF switch output signal, thereby can estimate according to the frequency spectrum of output signal the direction of wireless signal.

Single channel radio direction-finding system provided by the invention, its principle of work is: adopt single-pole double throw RF switch at wireless radio-frequency front-end, according to specific sequential, periodically open each antenna element passage, realize that the single channel of radio signal receives.When radio signal incides on aerial array from different directions, the spectrum structure difference of the injection radio signal that passage receives frequently.The spectrum structure of the radio signal received by analysis, thereby the incident direction of estimation radio signal.

Compared with prior art, the present invention has following technical characterstic:

Single channel radio direction-finding system provided by the invention, system architecture is simple, cost is low, and can measure the incident direction of a plurality of incoherent radio signals that simultaneously arrive, and the incident angle of measuring wide-band radio signal.

The accompanying drawing explanation

By reading the detailed description of non-limiting example being done with reference to the following drawings, it is more obvious that other features, objects and advantages of the present invention will become:

Fig. 1 is system architecture diagram of the present invention;

The control sequential schematic diagram that Fig. 2 is single-pole double throw RF switch;

Output signal schematic diagram under the current control sequential that Fig. 3 is single-pole double throw RF switch;

Fig. 4 is two illustratons of model that radio signal carry out direction finding of single channel radio direction-finding system to incident from different directions;

Fig. 5 is two results that radio signal carry out direction finding of single channel radio direction-finding system to incident from different directions;

In figure: 1 is aerial array, and 2 is the single-pole double throw RF switch module, and 3 is low noise amplifier, and 4 is local oscillation signal generation module, 5 is down conversion module, and 6 is low-pass filtering module, and 7 is analog-to-digital conversion module, 8 is spectrum analysis module, and 9 is control module, and 10 is the output display module.

Embodiment

Below embodiments of the invention are elaborated: the present embodiment is implemented take technical solution of the present invention under prerequisite, has provided detailed embodiment and concrete operating process.It should be pointed out that to those skilled in the art, without departing from the inventive concept of the premise, can also make some distortion and improvement, these all belong to protection scope of the present invention.

Please consult Fig. 1 to Fig. 5 simultaneously.

The present embodiment provides a kind of single channel radio direction-finding system, comprise aerial array 1, single-pole double throw RF switch module 2, receiving RF channel, spectrum analysis module 8, control module 9 and output display module 10, described aerial array 1 is connected with single-pole double throw RF switch module 2, described single-pole double throw RF switch module 2 is connected with receiving RF channel, described receiving RF channel is connected with spectrum analysis module 8, described spectrum analysis module 8 is connected with control module 9, described control module 9 is connected with output display module 10 with single-pole double throw RF switch module 2 respectively, wherein:

-aerial array, for receiving the radio signal of incident;

-single-pole double throw RF switch module, for the radio signal of periodically selecting aerial array to receive, and the feed-in receiving RF channel;

-receiving RF channel, carry out the radio signal of reception low noise amplification, downconvert to intermediate-freuqncy signal and suppress the high fdrequency component produced, and obtains analog if signal, then analog if signal is converted to digital signal;

-spectrum analysis module is estimated the fundamental component frequency spectrum of the digital signal exported on receiving RF channel and the frequency spectrum of harmonic component for the first time produced by the single-pole double throw RF switch module in numeric field;

-control module, control the periodicity of single-pole double throw RF switch module and open and turn-off by output logic signal; By relatively fundamental component and the relativeness of the frequency spectrum of harmonic component for the first time, obtain the radio incident direction;

-output display module, control module by the radio incident direction information output that obtains to display module and show.

Further, when described aerial array carries out the one dimension direction finding, adopt two antenna elements.

Further, described single-pole double throw RF switch module is single-pole double throw RF switch or is the combination of power splitter and single-pole single-throw switch (SPST).

Further, described single-pole double throw RF switch module is carried out periodic samples, and the radio signal of feed-in receiving RF channel not only comprises the original signal spectrum composition, also comprises with switching frequency f _peach harmonic component for the cycle generation.

Further, the switching frequency f of described single-pole double throw RF switch module _pand meet following relation between the bandwidth B of receiving RF channel:

f _p＞2B。

Further, described receiving RF channel is injection receiving cable frequently, comprise low noise amplifier 3, local oscillation signal generation module 4, down conversion module 5, low-pass filtering module 6 and analog-to-digital conversion module 7, wherein, described low noise amplifier 3 is connected with single-pole double throw RF switch module 2, described down conversion module 5 is connected with low-pass filtering module 6 with low noise amplifier 3, local oscillation signal generation module 4 respectively, described low-pass filtering module 6 is connected with analog-to-digital conversion module 7, described analog-to-digital conversion module 7 is connected with spectrum analysis module 8, wherein:

-low noise amplifier 3, carry out low noise amplification for the radio signal to receiving;

-local oscillation signal generation module 4, the required local oscillation signal for generation of down coversion;

-down conversion module 5, downconvert to intermediate-freuqncy signal for the radio signal by receiving;

-low-pass filtering module 6, carry out low-pass filtering for the signal to after down coversion, the high fdrequency component that filtering produces after down conversion module;

-analog-to-digital conversion module 7, be converted to digital signal by the analog intermediate frequency signal obtained.

Further, described spectrum analysis module is by spectrum estimation special chip, DSP chip (DSP) or programmable logic chip (CPLD, FPGA) and utilize discrete Fourier transformation (DFT) or Fast Fourier Transform (FFT) (FFT) method is estimated.

Further, described control module realizes the control to the single-pole double throw RF switch module by single-chip microcomputer, digital signal processor (DSP) or programmable logic chip (CPLD, FPGA).

Further, described control module obtains the method for radio incident direction, is specially:

By analysis and comparison fundamental component frequency spectrum Γ ₀with harmonic component frequency spectrum Γ for the first time ₁between relation, obtain radio incident direction θ, concrete calculated relationship is as follows:

$\mathrm{\θ}=-\arcsin \left(\frac{\mathrm{\λ}}{\mathrm{\πD}}\arctan \frac{\mathrm{\π}{\mathrm{\Γ}}_1}{2{\mathrm{\Γ}}_0}\right)$

Wherein, λ is the wavelength value corresponding for fundamental component, and D is the distance between antenna element; When the signal of incident is broadband rf signal, can select the fundamental component of some frequencies and harmonic component for the first time to compare, each frequency place is estimated to the angle information obtained averages as the incident direction of broadband rf signal.

Be specially:

-aerial array 1, for the received RF radio signal;

-single-pole double throw RF switch 2, for the reception of switching controls wireless radiofrequency electric signal;

-low noise amplifier 3, carry out low noise amplification for the radiofrequency signal to receiving;

-local oscillation signal generation module 4, the required local oscillation signal for generation of down coversion;

-down conversion module 5, downconvert to intermediate-freuqncy signal for the radiofrequency signal by receiving;

-low-pass filtering module 6, carry out low-pass filtering for the signal to after down coversion, the high-frequency signal that filtering produces after down conversion module;

-analog-to-digital conversion module 7 is digital signal by the analog signal conversion after down coversion;

-spectrum analysis module 8, the digital signal that analog-to-digital conversion module (7) is obtained is carried out analysis of spectrum

-control module 9, the state of control high-speed radio-frequency switch, the spectrum information obtained by spectrum analysis module (8) is estimated the radio incident direction, and output display;

-output display module 10, show the estimated radio directional information gone out.

Utilize the periodically reception of radio signal on control antenna array 1 of radio-frequency (RF) switch; Control module 9 draws the incident direction of radio signal by the relativeness between each frequency component that relatively spectrum analysis module 8 obtains.

Aerial array: for receiving the radio signal of incident, when carrying out the one dimension direction finding, adopt two antenna elements.

Single-pole double throw RF switch: for periodically selecting the radio signal received on each unit of aerial array, and feed-in injection frequency receiving cable.Due to the periodic samples of radio-frequency (RF) switch, the radio signal of feed-in radio-frequency channel not only comprises the original signal spectrum composition, and with switching frequency f _pfor the cycle produces the each harmonic component.Undistorted for guaranteeing that sampling obtains radio signal, should meet following relation between the switching frequency of high-speed radio-frequency switch and the bandwidth B of received RF signal:

f _p＞2B。

Receiving RF channel: carry out low noise amplification, by low-converter, spectrum component moved to intermediate frequency for the radio signal by reception, and by analog to digital converter, the analog if signal obtained is converted to digital signal.As shown in Figure 1, receiving cable is comprised of low noise amplifier 3, local oscillation signal generation module 4, down conversion module 5, low-pass filtering module 6 and analog-to-digital conversion module 7.

Spectrum analysis module: the spectrum component that utilizes the intermediate-freuqncy signal of exporting on discrete Fourier transformation (DFT) or Fast Fourier Transform (FFT) (FFT) method estimation receiving RF channel.As shown in Figure 1, spectrum analysis module is realized by spectrum estimation special chip (8).

Control module: the periodicity that control module is controlled radio-frequency (RF) switch by output logic signal is opened and is turn-offed.As shown in Figure 1, control module is by chip microcontroller.Receive the fundamental component frequency spectrum Γ of signal by analysis and comparison ₀with the frequency spectrum Γ of harmonic component for the first time ₁between relation obtain the incident direction θ of radio signal.Concrete calculated relationship is as follows:

$\mathrm{\θ}=-\arcsin \left(\frac{\mathrm{\λ}}{\mathrm{\πD}}\arctan \frac{\mathrm{\π}{\mathrm{\Γ}}_1}{2{\mathrm{\Γ}}_0}\right)$

Wherein, λ is the wavelength value corresponding for fundamental component, and D is the distance between antenna element.When the signal of incident is broadband rf signal, can select the fundamental component of some frequencies and harmonic component for the first time to compare, each frequency place is estimated to the angle information obtained averages as the incident direction of broadband rf signal.Therefore, the present invention has the ability of measuring the wide-band radio signal incident direction.

The output display module: the passage control module shows radio incident direction information output to the display module obtained.

The single channel radio direction-finding system that the present embodiment provides, its course of work is: by control module output control signal, control single-pole double throw RF switch and periodically connect two antenna elements.The radio signal received on two antenna elements is by single-pole double throw RF switch timesharing feed-in low noise amplification module, after low noise amplification, the radiofrequency signal received is converted to intermediate frequency by down conversion module, and suppresses the high fdrequency component wherein produced by low-pass filtering.Utilize analog-to-digital conversion module that the analog if signal of output is converted to digital signal, then estimated by spectrum analysis module frequency spectrum of fundamental component to received signal and the harmonic component for the first time that produced by switch in numeric field.In control module, by relatively fundamental component and the relativeness of the frequency spectrum of harmonic component for the first time, obtain the direction of the radio signal of incident.Last control module will estimate that the incident direction obtained exports display module to and shows.

Refer to Fig. 2 and Fig. 3, provided the control sequential of single-pole double throw RF switch in Fig. 2, and the schematic diagram of the radiofrequency signal that receives of single-pole double throw RF switch.In Fig. 2, when control signal is 1, single-pole double throw RF switch is got to an end, and when control signal is 0, single-pole double throw RF switch is got to the other end.As can be seen from Figure 3, when switching over, the signal of the wireless signal received is undergone mutation.The Sudden Changing Rate of phase place is relevant with the incident direction of wireless signal, and is reflected in the frequency spectrum of single-pole double throw RF switch output signal, thereby can estimate according to the frequency spectrum of output signal the direction of wireless signal.

Ultimate principle of the present invention is to adopt single-pole double throw RF switch at wireless radio-frequency front-end, according to specific sequential, periodically opens each antenna element passage, realizes that the single channel of radio signal receives.When radio signal incides on aerial array from different directions, the spectrum structure difference of the injection radio signal that passage receives frequently.The spectrum structure of the radio signal received by analysis, thereby the incident direction of estimation radio signal.

In the present embodiment:

The single-pole double throw RF switch module can be single-pole double throw RF switch, also single-pole double throw RF switch can be substituted with power splitter and single-pole single-throw switch (SPST);

Spectrum analysis module in Fig. 1 adopts the spectrum estimation special chip, for single-chip microcomputer, digital signal processor (DSP) or programmable logic chip (CPLD, FPGA) are estimated.

Below direction finding by two irrelevant information sources be that example is specifically described.

As shown in Figure 4, setting two incoherent information sources incides on the aerial array the present invention from both direction simultaneously.The spacing of aerial array is 15cm.Two information sources are simple signal, and its amplitude is 1, and carrier frequency is respectively 1GHz and 1.4GHz.Incident direction is respectively+40 ° and-20 ° with respect to the normal direction angle of aerial array.The signal to noise ratio snr of setting whole channel is 10dB.For 100 data points of each switching cycle sampling of single-pole double throw RF switch, sample altogether 10 cycles.After single-pole double throw RF switch periodically switches reception, the radiofrequency signal of output is gone forward side by side after the line frequency analysis of spectrum through single channel reception, down coversion, pattern conversion, calculate the incident direction of two radio signals according to aforesaid formula.

As shown in Figure 5, in figure, horizontal ordinate means angle, and the Diamond spot that ordinate is 1 means the actual incident direction of two radio signals, and the square dot that ordinate is 2 means the incident direction of two radio signals that estimation obtains.Can see, the evaluated error of first wireless signal is 0.25 °, and the evaluated error of second wireless signal is 0.18 °, successfully realizes the measurement to two radio signal directions of different directions incident.

Above specific embodiments of the invention are described.It will be appreciated that, the present invention is not limited to above-mentioned specific implementations, and those skilled in the art can make various distortion or modification within the scope of the claims, and this does not affect flesh and blood of the present invention.

Claims (9)

1. a single channel radio direction-finding system, it is characterized in that, comprise aerial array, the single-pole double throw RF switch module, receiving RF channel, spectrum analysis module, control module and output display module, described aerial array is connected with the single-pole double throw RF switch module, described single-pole double throw RF switch module is connected with receiving RF channel, described receiving RF channel is connected with spectrum analysis module, described spectrum analysis module is connected with control module, described control module is connected with the output display module with the single-pole double throw RF switch module respectively, wherein:

-aerial array, for receiving the radio signal of incident;

-single-pole double throw RF switch module, for the radio signal of periodically selecting aerial array to receive, and the feed-in receiving RF channel;

-receiving RF channel, carry out the radio signal of reception low noise amplification, downconvert to intermediate-freuqncy signal and suppress the high fdrequency component produced, and obtains analog if signal, then analog if signal is converted to digital signal;

-spectrum analysis module is estimated the fundamental component frequency spectrum of the digital signal exported on receiving RF channel and the frequency spectrum of harmonic component for the first time produced by the single-pole double throw RF switch module in numeric field;

-control module, control the periodicity of single-pole double throw RF switch module and open and turn-off by output logic signal; By relatively fundamental component and the relativeness of the frequency spectrum of harmonic component for the first time, obtain the radio incident direction;

-output display module, control module by the radio incident direction information output that obtains to display module and show.

2. single channel radio direction-finding system according to claim 1, is characterized in that, when described aerial array carries out the one dimension direction finding, adopts two antenna elements.

3. single channel radio direction-finding system according to claim 1, is characterized in that, described single-pole double throw RF switch module is single-pole double throw RF switch or is the combination of power splitter and single-pole single-throw switch (SPST).

4. according to the described single channel radio direction-finding system of claim 1 or 3, it is characterized in that, described single-pole double throw RF switch module is carried out periodic samples, and the radio signal of feed-in receiving RF channel not only comprises the original signal spectrum composition, also comprises with switching frequency f _peach harmonic component for the cycle generation.

5. single channel radio direction-finding system according to claim 4, is characterized in that, the switching frequency f of described single-pole double throw RF switch module _pand meet following relation between the bandwidth B of receiving RF channel:

f _p＞2B。

6. single channel radio direction-finding system according to claim 1, it is characterized in that, described receiving RF channel is injection receiving cable frequently, comprise low noise amplifier, local oscillation signal generation module, down conversion module, low-pass filtering module and analog-to-digital conversion module, wherein, described low noise amplifier is connected with the single-pole double throw RF switch module, described down conversion module respectively with low noise amplifier, local oscillation signal generation module is connected with low-pass filtering module, described low-pass filtering module is connected with analog-to-digital conversion module, described analog-to-digital conversion module is connected with spectrum analysis module, wherein:

-low noise amplifier, carry out low noise amplification for the radio signal to receiving;

-local oscillation signal generation module, the required local oscillation signal for generation of down coversion;

-down conversion module, downconvert to intermediate-freuqncy signal for the radio signal by receiving;

-low-pass filtering module, carry out low-pass filtering for the signal to after down coversion, the high fdrequency component that filtering produces after down conversion module;

-analog-to-digital conversion module, be converted to digital signal by the analog intermediate frequency signal obtained.

7. single channel radio direction-finding system according to claim 1, it is characterized in that, described spectrum analysis module is by spectrum estimation special chip, DSP chip or programmable logic chip and utilize discrete Fourier transformation or the Fast Fourier Transform (FFT) method is estimated.

8. single channel radio direction-finding system according to claim 1, is characterized in that, described control module realizes the control to the single-pole double throw RF switch module by single-chip microcomputer, digital signal processor or programmable logic chip.

9. single channel radio direction-finding system according to claim 1, is characterized in that, described control module obtains the method for radio incident direction, is specially:

By analysis and comparison fundamental component frequency spectrum Γ ₀with harmonic component frequency spectrum Γ for the first time ₁between relation, obtain radio incident direction θ, concrete calculated relationship is as follows:

$\mathrm{\θ}=-\arcsin \left(\frac{\mathrm{\λ}}{\mathrm{\πD}}\arctan \frac{\mathrm{\π}{\mathrm{\Γ}}_1}{2{\mathrm{\Γ}}_0}\right)$

Wherein, λ is the wavelength value corresponding for fundamental component, and D is the distance between antenna element; When the signal of incident is broadband rf signal, can select the fundamental component of some frequencies and harmonic component for the first time to compare, each frequency place is estimated to the angle information obtained averages as the incident direction of broadband rf signal.

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