High-performance short-wave electrically small antenna receiver device and short-wave frequency hopping signal receiving and identifying method

Abstract

The invention discloses a high-performance short-wave electric small antenna receiver device which comprises a cylindrical alkali metal atom air chamber, parallel plate waveguide electrodes, an optical fiber, a lens, a sleeve, a detection laser, a coupling laser and a radio frequency signal source. The two electrode plates are attached to the opposite sides of the cylindrical alkali metal atom gas chamber; the lens and the sleeve penetrate through the two ends of the cylindrical alkali metal atom gas chamber; the optical fiber is arranged in the lens and the sleeve; the detection laser and the coupling laser are respectively connected with an optical fiber and are arranged in the directions of two ends of the cylindrical alkali metal atom gas chamber; the radio frequency signal source generates a required local oscillation short wave field. The invention breaks through the theoretical limit of the current short-wave electric small antenna receiving. The method is suitable for an environment near room temperature, is simple and easy to operate, and is beneficial to practicability. The method has the advantages of high sensitivity, large working bandwidth, large instantaneous bandwidth, arbitrary frequency identification and the like.

Description

Technical Field

[0001] The present invention relates to the field of shortwave frequency modulation signals, and in particular to a high-performance shortwave electric small antenna receiver device, and a shortwave frequency hopping signal receiving and identifying method. Background Art

[0002] Shortwave refers to electromagnetic waves with a frequency in the range of 3-30MHz, corresponding to a wavelength range of 10-100 meters. Electromagnetic waves in this band can be reflected without significant attenuation in the ionosphere, thereby realizing wireless communication without any relays. Compared with the microwave wireless communications that are currently widely used in daily life, shortwave has a lower frequency and a longer wavelength. Due to the properties of traditional metal electric dipole antennas, their length is required to match the wavelength of electromagnetic waves, and the required receiving antenna length will be much larger than that of microwave antennas. Due to various limitations, shortwave communication is difficult to use in daily life, but as the only long-distance wireless communication method without relays, it still has very important applications and needs in military communications, electronic countermeasures and other fields.

[0003] Frequency hopping technology refers to the technology of rapidly changing the carrier frequency over time. It can not only avoid external interference and multipath fading to a certain extent, but also effectively improve the confidentiality of communications.

[0004] The newly developed Rydberg atomic radio technology in recent years is different from the traditional metal antenna principle. It uses atoms to sense the electric field of electromagnetic waves in space and restores the various parameter information of electromagnetic waves through the laser spectrum of atoms. As an equivalent LC circuit, the minimum Q value of the metal antenna at a specific frequency has a clear relationship with the characteristic length, so the performance is greatly affected when its length is compressed. Therefore, it is difficult for electrically small antennas working in an electrically small area to have reliable performance. The characteristics of the Rydberg atomic antenna determine that its bandwidth, efficiency, etc. are not obviously related to its characteristic size. Therefore, compared with the metal dipole antenna, it has unique advantages in an electrically small area and is expected to provide more superior performance.

[0005] Therefore, in order to overcome the shortcomings of the existing metal electric small antenna technology, the existing frequency hopping receiver is improved to improve its sensitivity, large working bandwidth, large instantaneous bandwidth, arbitrary frequency recognition and other performances. Summary of the invention

[0006] In order to solve the above technical problems, a high-performance short-wave radio frequency receiving antenna device and method are proposed, which uses a three-level Rydberg EIT system, uses Rydberg atoms as mixers for short-wave radio frequency signals, and amplifies the performance of Rydberg atomic antennas. The probe light and coupling light excite the atoms to the Rydberg state, and through the AC Stark effect of the atoms, its laser spectrum can reflect the intermediate frequency signal after mixing the two short-wave radio frequency electric fields and the modulation information it carries.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows: A high-performance short-wave electric small antenna receiver device, including a cylindrical alkali metal atom gas chamber, a parallel plate waveguide electrode, an optical fiber, a lens and a sleeve, a detection laser, a coupling laser and a radio frequency signal source, The parallel plate waveguide electrode is two electrode plates parallel to each other, and the two electrode plates are bonded and arranged on opposite sides of the cylindrical alkali metal atom gas chamber; The lens and the sleeve pass through both ends of the cylindrical alkali metal atom gas chamber; The optical fiber is installed inside the lens and the sleeve; The detection laser and the coupling laser are respectively connected to the optical fiber and arranged at two end directions of the cylindrical alkali metal atom gas chamber; The radio frequency signal source generates the required local oscillator short-wave field and is connected to the parallel plate waveguide electrode via an SMA cable.

[0008] Preferably, the cross-sectional diameter of the cylindrical alkali metal atom gas chamber is 0.8-1.5 cm, the total length is 2.5-4 cm, and the wall thickness is 1-3 mm.

[0009] Preferably, the outer shell of the cylindrical alkali metal atom gas chamber is made of quartz glass, and the interior of the cylindrical alkali metal atom gas chamber is filled with alkali metal atom gas.

[0010] Preferably, the electrode plate 11 is made of copper, and one end of the electrode plate is open and aligned with the direction of the short-wave signal field in space.

[0011] Preferably, the two parallel electrode plates are respectively connected to the core layer and the cladding layer of the SMA cable.

[0012] A shortwave frequency hopping signal receiving method uses a high-performance shortwave small antenna receiver device as described above, and the method comprises the following steps: Step S1: the detection laser and the coupling laser respectively emit detection light and coupling light from two opposite directions along the optical fiber to the cylindrical alkali metal atomic gas chamber, and propagate in the same line in the cylindrical alkali metal atomic gas chamber in the opposite direction, so as to excite the atoms to the Rydberg state and generate an electromagnetically induced transparency effect; Step S2: The radio frequency signal source generates the required local oscillator short-wave field and feeds it into the cylindrical alkali metal atom gas chamber to form an AC Stark effect, and the radio frequency circuit is used to adjust and control the required local oscillator signal frequency and amplitude according to the needs of the received signal; Step S3: Use parallel plate waveguide electrodes to receive short-wave electromagnetic waves in space and input them into the atomic sensor. Use photoelectric detectors to detect the detection light to receive short-wave signals, and then obtain the information carried by the short-wave signal through signal processing and demodulation.

[0013] A method for identifying shortwave frequency hopping signals of arbitrary frequency, using a high-performance shortwave small antenna receiver device as described above, the method comprising the following steps: Step 1: The detection laser and the coupling laser respectively emit detection light and coupling light from two opposite directions along the optical fiber to the cylindrical alkali metal atomic gas chamber, and propagate in the same line in the cylindrical alkali metal atomic gas chamber in the opposite direction, so as to excite the atoms to the Rydberg state and generate an electromagnetically induced transparency effect; Step 2: multi-tone modulate the short-wave local oscillator field generated by the radio frequency signal source to form a frequency comb with a fixed comb tooth interval, which is called the first set of frequency combs; Step 3: Use the parallel plate waveguide electrode to receive the short-wave electromagnetic wave in the space and input it into the atomic sensor, detect the detection light through the photodetector to realize the reception of the short-wave signal, and read out the beat frequency signal of the signal and the nearest comb teeth; Step 4: Change the multi-tone modulation characteristics so that the short-wave local oscillator field generated by the frequency signal source becomes a frequency comb with another comb tooth spacing, which is called the second set of frequency combs; Step 5: Obtain the beat frequency signal of the signal field and the nearest comb teeth in the second set of frequency combs through the beat frequency; Step 6: Obtain the frequency of the unknown frequency signal field through the formula.

[0014] Preferably, the first set of frequency combs with larger spacing has teeth spaced apart by δ, and the second set of frequency combs with smaller spacing has teeth spaced apart by Δ.

[0015] Preferably, the signal field in the space will respectively generate higher beat frequency signals a and b with the most adjacent comb teeth in the two sets of frequency combs, and respectively generate beat frequency signals δ-a and Δ-b with the next adjacent comb teeth; By setting the comb teeth spacing condition, the ordinal numbers n of the two comb teeth in the two sets of comb teeth that are closest to the signal frequency can be made n1=n2, or n1=n2-1.

[0016] Preferably, the absolute frequencies of the starting teeth of the first set of frequency combs and the second set of frequency combs are marked as A and B respectively; The absolute frequency N corresponding to the last comb tooth of the first set of comb teeth and the absolute frequencies M, M-1 corresponding to the last two comb teeth of the second set of comb teeth must satisfy N≥ ; The frequency f of the signal field to be measured can be expressed as: 1), f=A+δ*n±a=B+Δ*(n+1)±b, or: 2), f =A+δ*n±a=B+Δ*n±b; Solving the equations yields a unique solution for the unknown frequency within the range covered by the frequency comb.

[0017] Beneficial technical effects of the present invention: The present invention provides a freely operable local oscillator through a parallel plate waveguide in a radio frequency circuit. The detection light signal passes through the atomic gas and enters the photodetector via an optical fiber, and is converted into an electrical signal for processing. The invention has strong practicality and is easy to integrate. While ensuring the performance of the shortwave receiver, it can also greatly compress the volume of the receiving antenna and greatly expand the operating frequency range of the receiver, breaking through the theoretical limit of the current shortwave small antenna reception.

[0018] The invention is suitable for an environment close to room temperature, the method is simple and easy to operate, and is beneficial to practicality.

[0019] The present invention has the advantages of high sensitivity, large working bandwidth, large instantaneous bandwidth, arbitrary frequency recognition, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the atomic shortwave receiver of the present invention; Figure 2 Shown is the schematic diagram of arbitrary frequency recognition. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments, but the scope of protection claimed in the present invention is not limited to the following specific embodiments.

[0022] like Figure 1 As shown, a high-performance short-wave electric small antenna receiver device includes a cylindrical alkali metal atomic gas chamber 10, a parallel plate waveguide electrode 11, an optical fiber 8, a lens and a sleeve 9, a detection laser 6, a coupling laser 7 and a radio frequency signal source 12.

[0023] The parallel plate waveguide electrode 11 is two electrode plates parallel to each other, and the two electrode plates are bonded and arranged on opposite sides of the cylindrical alkali metal atom gas chamber 10; the lens and the sleeve 9 pass through both ends of the cylindrical alkali metal atom gas chamber 10; the optical fiber 8 is installed inside the lens and the sleeve 9; The detection laser 6 and the coupling laser 7 are respectively connected to the optical fiber 8 and are arranged at both ends of the cylindrical alkali metal atom gas chamber 10; the radio frequency signal source 12 generates the required local oscillator short-wave field and is connected to the parallel plate waveguide electrode 11 through an SMA cable.

[0024] Specifically, the dimensions and materials of each component are as follows: The cross-sectional diameter of the cylindrical alkali metal atom gas chamber 10 is 0.8-1.5 cm, the total length is 2.5-4 cm, and the wall thickness is 1-3 mm. The preferred value is that the cylindrical alkali metal atom gas chamber 10 has a diameter of 1 cm and a length of 3 cm.

[0025] The outer shell of the cylindrical alkali metal atom gas chamber 10 is made of quartz glass, and the interior of the cylindrical alkali metal atom gas chamber 10 is filled with alkali metal atom gas.

[0026] The electrode plate is made of copper, and one end of the electrode plate is open and aligned with the direction of the short-wave signal field in space. The two parallel electrode plates 11 are respectively connected to the core layer and the cladding of the SMA cable, and the relative positions are fixed by insulating polytetrafluoroethylene material.

[0027] This embodiment also provides a shortwave frequency hopping signal receiving method, which uses a high-performance shortwave small antenna receiver device as described above, and the method includes the following steps: Step S1: the detection laser 6 and the coupling laser 7 respectively emit detection light and coupling light from two opposite directions and send them along the optical fiber 8 to the cylindrical alkali metal atom gas chamber 10, and propagate in the same line in the cylindrical alkali metal atom gas chamber 10 in the opposite direction, so as to excite the atoms to the Rydberg state and generate an electromagnetically induced transparency effect; Step S2: The radio frequency signal source 12 generates the required local oscillator short-wave field and feeds it into the cylindrical alkali metal atom gas chamber 10 to form an AC Stark effect. The radio frequency circuit is used to adjust and control the required local oscillator signal frequency and amplitude according to the needs of the received signal; Step S3: Use the parallel plate waveguide electrode 11 to receive short-wave electromagnetic waves in space and input them into the atomic sensor. The photoelectric detector detects the detection light to receive the short-wave signal, and then obtains the information carried by the short-wave signal through signal processing and demodulation.

[0028] This embodiment also provides a method for identifying an arbitrary frequency shortwave frequency hopping signal, using a high-performance shortwave small antenna receiver device as described above, the method comprising the following steps: Step 1: The detection laser 6 and the coupling laser 7 respectively emit detection light and coupling light from two opposite directions along the optical fiber 8 to the cylindrical alkali metal atom gas chamber 10, and propagate in the same line in the cylindrical alkali metal atom gas chamber 10 in the opposite direction, so as to excite the atoms to the Rydberg state and generate an electromagnetically induced transparency effect; Step 2: Multi-tone modulation is performed on the short-wave local oscillator field generated by the RF signal source 12 to form a frequency comb with a fixed comb tooth interval, which is called the first set of frequency combs 18; Step 3: Use the parallel plate waveguide electrode 11 to receive the short-wave electromagnetic wave in the space and input it into the atomic sensor, detect the detection light through the photodetector to realize the reception of the short-wave signal, and read out the beat frequency signal of the signal and the nearest comb teeth; Step 4: changing the multi-tone modulation characteristics so that the short-wave local oscillator field generated by the frequency signal source becomes a frequency comb with another comb tooth spacing, which is called the second set of frequency combs 19; Step 5: Obtain the beat frequency signal of the signal field and the nearest comb teeth in the second set of frequency combs 19 through the beat frequency; Step 6: Obtain the frequency of the unknown frequency signal field through the formula.

[0029] Preferably, the first set of frequency combs 18 with larger intervals have teeth with an interval of δ, and the second set of frequency combs 19 with smaller intervals have teeth with an interval of Δ.

[0030] Preferably, the signal field 13 in the space will generate higher beat frequency signals a and b with the nearest comb tooth 14 in the frequency comb 18 and the nearest comb tooth 16 in the frequency comb 19, respectively, and generate beat frequency signals δ-a and Δ-b with the next nearest comb teeth 15 and 17, respectively; By setting the comb teeth spacing condition, the ordinal numbers n of the two comb teeth in the two sets of comb teeth that are closest to the signal frequency can be made n1=n2, or n1=n2-1.

[0031] Preferably, the absolute frequencies of the starting teeth of the first set of frequency combs 18 and the second set of frequency combs 19 are marked as A and B respectively; The absolute frequency N corresponding to the last comb tooth of the first set of comb teeth and the absolute frequencies M, M-1 corresponding to the last two comb teeth of the second set of comb teeth must satisfy N≥ ; The frequency f of the signal field to be measured can be expressed as: 1), f=A+δ*n±a=B+Δ*(n+1)±b, or: 2), f =A+δ*n±a=B+Δ*n±b; Solving the equations yields a unique solution for the unknown frequency within the range covered by the frequency comb.

[0032] The present invention provides a freely operable local oscillator through a parallel plate waveguide in a radio frequency circuit. The detection light signal passes through the atomic gas and enters the photodetector via an optical fiber, and is converted into an electrical signal for processing. The invention has strong practicality and is easy to integrate. While ensuring the performance of the shortwave receiver, it can also greatly compress the volume of the receiving antenna and greatly expand the operating frequency range of the receiver, breaking through the theoretical limit of the current shortwave small antenna reception.

[0033] The invention is suitable for an environment close to room temperature, the method is simple and easy to operate, and is beneficial to practicality.

[0034] The present invention has the advantages of high sensitivity, large working bandwidth, large instantaneous bandwidth, arbitrary frequency recognition, etc.

[0035] According to the disclosure and teaching of the above description, those skilled in the art to which the present invention belongs may also make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the invention should also fall within the scope of protection of the claims of the present invention. In addition, although some specific terms are used in this specification, these terms are only for the convenience of description and do not constitute any limitation to the invention.

Claims

1. A high performance shortwave small antenna receiver device, characterized in that: It includes a cylindrical alkali metal atom gas chamber, a parallel plate waveguide electrode, an optical fiber, a lens and a sleeve, a detection laser, a coupling laser and a radio frequency signal source. The parallel plate waveguide electrode is two electrode plates parallel to each other, and the two electrode plates are bonded and arranged on opposite sides of the cylindrical alkali metal atom gas chamber; The lens and the sleeve pass through both ends of the cylindrical alkali metal atom gas chamber; The optical fiber is installed inside the lens and the sleeve; The detection laser and the coupling laser are respectively connected to the optical fiber and arranged at two end directions of the cylindrical alkali metal atom gas chamber; The radio frequency signal source generates the required local oscillator short-wave field and is connected to the parallel plate waveguide electrode via an SMA cable.

2. A high performance shortwave small antenna receiver device as claimed in claim 1, characterized in that: The cross-sectional diameter of the cylindrical alkali metal atom gas chamber is 0.8-1.5 cm, the total length is 2.5-4 cm, and the wall thickness is 1-3 mm.

3. A high performance shortwave small antenna receiver device as claimed in claim 1, characterized in that: The outer shell of the cylindrical alkali metal atom gas chamber is made of quartz glass, and the interior of the cylindrical alkali metal atom gas chamber is filled with alkali metal atom gas.

4. A high performance shortwave small antenna receiver device as claimed in claim 1, characterized in that: The electrode plate 11 is made of copper, and one end of the electrode plate is open and aligned with the direction of the short-wave signal field in space.

5. A high performance shortwave small antenna receiver device as claimed in claim 1, characterized in that: The two parallel electrode plates are respectively connected to the core layer and the cladding layer of the SMA cable.

6. A shortwave frequency hopping signal receiving method, using a high-performance shortwave small antenna receiver device as claimed in any one of claims 1 to 5, characterized in that: The method comprises the following steps: Step S1: the detection laser and the coupling laser respectively emit detection light and coupling light from two opposite directions along the optical fiber to the cylindrical alkali metal atomic gas chamber, and propagate in the same line in the cylindrical alkali metal atomic gas chamber in the opposite direction, so as to excite the atoms to the Rydberg state and generate an electromagnetically induced transparency effect; Step S2: The radio frequency signal source generates the required local oscillator short-wave field and feeds it into the cylindrical alkali metal atom gas chamber to form an AC Stark effect, and the radio frequency circuit is used to adjust and control the required local oscillator signal frequency and amplitude according to the needs of the received signal; Step S3: Use parallel plate waveguide electrodes to receive short-wave electromagnetic waves in space and input them into the atomic sensor. Use photoelectric detectors to detect the detection light to receive short-wave signals, and then obtain the information carried by the short-wave signal through signal processing and demodulation.

7. A method for identifying shortwave frequency hopping signals of arbitrary frequency, using a high-performance shortwave small antenna receiver device as described in any one of claims 1 to 5, characterized in that: The method comprises the following steps: Step 1: The detection laser and the coupling laser respectively emit detection light and coupling light from two opposite directions along the optical fiber to the cylindrical alkali metal atomic gas chamber, and propagate in the same line in the cylindrical alkali metal atomic gas chamber in the opposite direction, so as to excite the atoms to the Rydberg state and generate an electromagnetically induced transparency effect; Step 2: multi-tone modulate the short-wave local oscillator field generated by the radio frequency signal source to form a frequency comb with a fixed comb tooth interval, which is called the first set of frequency combs; Step 3: Use the parallel plate waveguide electrode to receive the short-wave electromagnetic wave in the space and input it into the atomic sensor, detect the detection light through the photodetector to realize the reception of the short-wave signal, and read out the beat frequency signal of the signal and the nearest comb teeth; Step 4: Change the multi-tone modulation characteristics so that the short-wave local oscillator field generated by the frequency signal source becomes a frequency comb with another comb tooth spacing, which is called the second set of frequency combs; Step 5: Obtain the beat frequency signal of the signal field and the nearest comb teeth in the second set of frequency combs through the beat frequency; Step 6: Obtain the frequency of the unknown frequency signal field through the formula.

8. The method for identifying an arbitrary frequency shortwave frequency hopping signal as claimed in claim 7, characterized in that: The first set of frequency combs with larger spacing has teeth spaced apart by δ, and the second set of frequency combs with smaller spacing has teeth spaced apart by Δ.

9. A method for identifying an arbitrary frequency shortwave frequency hopping signal as claimed in claim 8, characterized in that: The signal field in space will generate higher beat frequency signals a and b with the nearest comb teeth in the two sets of frequency combs, and beat frequency signals δ-a and Δ-b with the next nearest comb teeth respectively; By setting the comb teeth spacing condition, the ordinal numbers n of the two comb teeth in the two sets of comb teeth that are closest to the signal frequency can be made n1=n2, or n1=n2-1.

10. The method for identifying an arbitrary frequency shortwave frequency hopping signal according to claim 8, characterized in that: The absolute frequencies of the starting teeth of the first set of frequency combs and the second set of frequency combs are marked as A and B respectively; The absolute frequency N corresponding to the last comb tooth of the first set of comb teeth and the absolute frequencies M, M-1 corresponding to the last two comb teeth of the second set of comb teeth must satisfy N≥ ; The frequency f of the signal field to be measured can be expressed as: 1), f=A+δ*n±a=B+Δ*(n+1)±b, or: 2), f =A+δ*n±a=B+Δ*n±b; Solving the equations yields a unique solution for the unknown frequency within the range covered by the frequency comb.

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