Dual-polarized electrically small antenna probe for VHF (very high frequency) band

Abstract

The utility model discloses a dual-polarization electrically small antenna probe used for a VHF frequency band, a first linear polarization matching dipole antenna unit and a second linear polarization matching dipole antenna unit which have the same working frequency respectively comprise a PCB substrate, an antenna copper sheet, a Balun matching circuit and a radio frequency line, the PCB substrates are orthogonally spliced to form a cross structure, and the antenna copper sheet and the Balun matching circuit are arranged in the cross structure. The surface of one end of each PCB substrate is printed with an antenna copper sheet, the antenna copper sheets on each PCB substrate are arranged in a bilateral symmetry mode along an orthogonal splicing line of the PCB substrate, and each PCB substrate is provided with a balun matching circuit and a radio frequency line. The two groups of antenna copper sheets on each PCB substrate are respectively connected and conducted with the Balun matchers of the Balun matching circuits through radio frequency lines to realize antenna input feed, the miniaturization of the antenna probe is obviously realized, the compact application requirement can be met, and the stability and the reliability of antenna signal transmission are effectively improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a technical field of antenna, especially a kind of dual polarized electric small antenna probe for VHF frequency band. BACKGROUND

[0002] VHF frequency band (30MHz to 300MHz) is widely used in multiple fields, including FM broadcast, terrestrial television broadcast, aviation communication, maritime communication, military communication, emergency service, low-orbit satellite communication and radio astronomy, etc., due to its stable signal propagation and strong anti-interference capability. In addition, VHF frequency band is also used in industrial remote control, medical imaging, amateur radio, unmanned aerial vehicle control and near-field detection, which is an important frequency band resource in multiple fields.

[0003] Compared with traditional single-probe system, multi-probe antenna test system has higher test speed. However, the size of existing VHF probe antenna is usually close to half wavelength of working frequency, for example, about 3 meters at 50MHz and about 0.5 meters at 300MHz. Such large size is difficult to meet the compact design requirement of multi-probe test system, therefore, miniaturization has become an important development direction of VHF probe antenna. SUMMARY

[0004] In order to overcome the above-mentioned defects, the utility model provides a kind of dual polarized electric small antenna probe for VHF frequency band, which can realize significant miniaturization and meet the compact application requirement.

[0005] The utility model discloses a kind of dual polarized electric small antenna probe for VHF frequency band, including first line polarization matching dipole antenna unit and second line polarization matching dipole antenna unit, the size and working frequency of first line polarization matching dipole antenna unit and second line polarization matching dipole antenna unit are identical, first line polarization matching dipole antenna unit and second line polarization matching dipole antenna unit all include PCB substrate, antenna copper sheet, balun matching circuit and radio frequency wire, the PCB substrate of first line polarization matching dipole antenna unit and second polarization matching dipole antenna unit orthogonal splicing forms cross structure, the surface of one end of the PCB substrate of first line polarization matching dipole antenna unit and second polarization matching dipole antenna unit is respectively printed with antenna copper sheet, and antenna copper sheet on each PCB substrate is symmetrically arranged along PCB substrate orthogonal splicing line left and right, each PCB substrate is equipped with one balun matching circuit and one radio frequency wire, two groups of antenna copper sheet on each PCB substrate are connected with the balun matching device of balun matching circuit by radio frequency wire and are connected to realize antenna input feed.

[0006] As a further improvement of the utility model, the first linear polarization matching dipole antenna unit and the second linear polarization matching dipole antenna unit are symmetrically printed with multiple antenna copper sheets on both sides of the orthogonal splicing line, and adjacent antenna copper sheets are connected in series through patch resistors.

[0007] As a further improvement of the utility model, the PCB substrate of the first linear polarization matching dipole antenna unit and the second linear polarization matching dipole antenna unit is symmetrically printed with multiple antenna copper sheets on both sides of the orthogonal splicing line, and adjacent antenna copper sheets are connected in series through patch resistors.

[0008] As a further improvement of the utility model, the working frequency of the first linear polarization matching dipole antenna unit and the second linear polarization matching dipole antenna unit covers 50MHz to 400MHz, and the size of the first linear polarization matching dipole antenna unit and the second linear polarization matching dipole antenna unit is: length 380mm, width 240mm.

[0009] As a further improvement of the utility model, the first linear polarization matching dipole antenna unit and the second linear polarization matching dipole antenna unit adopt Taconic RF35 as the medium of the PCB substrate, the layer thickness of the medium is 0.76mm, the dielectric constant of the medium is 3.5±0.05, and the loss factor is 0.0018 (at 10GHz).

[0010] As a further improvement of the utility model, the PCB substrate is covered with antenna copper sheets on one side, and the antenna copper sheets adopt copper foils with a thickness of 35μm.

[0011] As a further improvement of the utility model, the radio frequency wire is provided with a magnetic ring for suppressing high-frequency interference and optimizing signal transmission performance.

[0012] As a further improvement of the utility model, the first linear polarization matching dipole antenna unit and the second linear polarization matching dipole antenna unit also each include an RG174 coaxial cable, the inner core wire and the shielding mesh wire at one end of the RG174 coaxial cable are welded on a balun impedance adapter of a balun matching circuit to realize connection conduction with the balun matching circuit, and the other end of the RG174 coaxial cable forms a feed port of the first linear polarization matching dipole antenna unit and the second linear polarization matching dipole antenna unit.

[0013] As a further improvement of the utility model, the inner core wire of the radio frequency wire is welded to the pin of the impedance adapter of the balun matching circuit at one end, and the inner core wire of the radio frequency wire is welded to the printed circuit end formed by the antenna copper sheet printed on the surface of the PCB substrate at the other end, and the shielding mesh wire of the radio frequency wire is welded to the ground pad of the impedance adapter, so as to realize reliable signal transmission and stable electrical performance.

[0014] As a further improvement of the utility model, a non-metallic shell is further arranged, and the first linear polarization matching dipole antenna unit and the second linear polarization matching dipole antenna unit are fixedly installed in the non-metallic shell and positioned and protected by the non-metallic shell.

[0015] The utility model has the advantages that the two linear polarization matching dipole antenna units are orthogonally spliced, the size of the antenna probe is significantly reduced to 380mm in length and 240mm in width, the antenna probe is significantly miniaturized, compact application requirements can be met, the problem that the size of the traditional VHF probe antenna is too large and the probe antenna is difficult to be used for multi-probe integration is solved, the influence of the leakage current on the test accuracy is significantly suppressed by the balun matching circuit and the magnetic ring structure, and therefore the stability and reliability of the antenna signal transmission are effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a perspective view of the utility model;

[0017] Figure 2 It is a design drawing of the first linear polarization matching dipole antenna unit of the utility model;

[0018] Figure 3 It is a design drawing of the second linear polarization matching dipole antenna unit of the utility model;

[0019] Figure 4 It is a front view of the radio frequency wire connecting structure of the utility model;

[0020] Figure 5 It is Figure 4 It is an enlarged view of the middle A part;

[0021] Figure 6 It is an assembled structure perspective exploded view of the antenna probe and the non-metallic shell of the utility model;

[0022] Figure 7 It is a perspective view of the non-metallic shell of the utility model;

[0023] Figure 8 It is a front view of the non-metallic shell of the utility model;

[0024] Figure 9The utility model discloses a nonmetallic shell plan view of the utility model,

[0025] Figure 10 The utility model discloses a nonmetallic shell left view of the utility model, Specific implementation

[0026] Embodiment 1: a dual-polarized electrically small antenna probe for VHF frequency band, comprising a first linear polarization matching dipole antenna unit 1 and a second linear polarization matching dipole antenna unit 2, the size and operating frequency of the first linear polarization matching dipole antenna unit 1 and the second linear polarization matching dipole antenna unit 2 are same, the first linear polarization matching dipole antenna unit 1 and the second linear polarization matching dipole antenna unit 2 all comprise a PCB substrate 3, an antenna copper sheet 4, a balun matching circuit 5 and a radio frequency wire 6, the PCB substrates 3 of the first linear polarization matching dipole antenna unit 1 and the second polarization matching dipole antenna unit are orthogonally spliced to form a cross structure, the antenna copper sheets 4 are respectively printed on the one end surface of the PCB substrates 3 of the first linear polarization matching dipole antenna unit 1 and the second polarization matching dipole antenna unit, and the antenna copper sheets 4 on each PCB substrate 3 are symmetrically arranged along the orthogonal splicing line of the PCB substrate 3, one balun matching circuit 5 and one radio frequency wire 6 are arranged on each PCB substrate 3, and two groups of antenna copper sheets 4 on each PCB substrate 3 are connected to the balun matching device of the balun matching circuit 5 through the radio frequency wire 6 to realize antenna input feed. By orthogonally splicing the first linear polarization matching dipole antenna unit 1 and the second linear polarization matching dipole antenna unit to form an integrated structure, the antenna probe is miniaturized, and compared with the typical wavelength of the VHF frequency band (for example, 50MHz corresponds to about 6 meters, and 300MHz corresponds to about 1 meter), the size is significantly reduced, and then the compact application requirement is met.

[0027] The first linear polarization matching dipole antenna unit 1 is formed with a first open slot 7 in the middle of the lower end of the PCB substrate 3, the second polarization matching dipole antenna unit is formed with a second open slot 8 in the middle of the upper end of the PCB substrate 3, and the substrates of the first linear polarization matching dipole antenna unit 1 and the second polarization matching dipole antenna unit are orthogonally spliced by the first open slot 7 and the second open slot 8. By setting the first open slot 7 at the lower end of the PCB substrate 3 of the first linear polarization matching dipole antenna unit 1 and the second open slot 8 at the upper end of the PCB substrate 3 of the second linear polarization matching dipole antenna unit 2, the orthogonal splicing of the two antennas can be realized by the cross insertion of the two open slots, the lengths of the first open slot 7 and the second open slot 8 are different, and then the two linear polarization matching dipole antenna units are aligned at both ends after splicing, so that the structural adaptability and electrical performance are optimized.

[0028] The PCB substrate 3 of the first linear polarization matching dipole antenna unit 1 and the second linear polarization matching dipole antenna unit 2 is symmetrically printed with multiple antenna copper sheets 4 on both sides of the orthogonal splicing line.

[0029] The working frequency of the first linear polarization matching dipole antenna unit 1 and the second linear polarization matching dipole antenna unit 2 covers 50MHz to 400MHz, and the size of the first linear polarization matching dipole antenna unit 1 and the second linear polarization matching dipole antenna unit 2 is: length 380mm, width 240mm.

[0030] The size of the antenna probe is reduced to length 380mm, width 240mm, which is significantly reduced compared to the typical wavelength of the VHF frequency band (for example, 50MHz corresponds to about 6 meters, and 300MHz corresponds to about 1 meter).

[0031] The first linear polarization matching dipole antenna unit 1 and the second linear polarization matching dipole antenna unit 2 use Taconic RF35 as the medium of the PCB substrate 3, the layer thickness of the medium is 0.76mm, the dielectric constant of the medium is 3.5±0.05, and the loss factor is 0.0018 (at 10GHz).

[0032] The PCB substrate 3 is covered with antenna copper sheets 4 on one side, and the antenna copper sheets 4 use copper foil with a thickness of 35μm, which can meet the design requirements of the VHF frequency band high-performance antenna probe.

[0033] The radio frequency wire 6 is provided with a magnetic ring 10 for suppressing high-frequency interference and optimizing signal transmission performance. By suppressing high-frequency interference and optimizing signal transmission performance through the magnetic ring 10, it is beneficial to suppress the influence of leakage current on test accuracy.

[0034] The first linear polarization matching dipole antenna unit 1 and the second linear polarization matching dipole antenna unit 2 also include an RG174 coaxial cable 11, and the inner core wire and shielding mesh wire at one end of the RG174 coaxial cable 11 are welded to the balun impedance adapter of the balun matching circuit 5 to realize connection and conduction with the balun matching circuit 5, and the other end of the RG174 coaxial cable 11 forms a feed port 12 of the first linear polarization matching dipole antenna unit 1 and the second linear polarization matching dipole antenna unit 2.

[0035] The inner core wire of the radio frequency line 6 is welded to the pin of the impedance adapter of the balun matching circuit 5 at one end, and is welded to the printed circuit end formed by the antenna copper sheet 4 printed on the surface of the PCB substrate 3 at the other end, and the shielding mesh wire of the radio frequency line 6 is welded to the ground pad of the impedance adapter, so as to realize reliable signal transmission and stable electrical performance. The probe setting pad is used for welding the integrated balun and matching circuit, and is used for realizing the conversion between balanced and unbalanced modes, so as to ensure the high-efficiency impedance matching and signal coupling between the balanced PCB antenna and the coaxial radio frequency line 6, and effectively suppress the influence of the leakage current on the probe performance. The radio frequency line 6 connected by welding effectively suppresses the leakage current and reduces signal interference, thereby improving the stability and reliability of signal transmission.

[0036] The first linearly polarized matching dipole antenna unit 1 and the second linearly polarized matching dipole antenna unit 2 are fixedly installed in the non-metallic shell 13, and are positioned and protected by the non-metallic shell 13. The non-metallic shell 13 is preferably a cross-shaped structure matched with the shape of the antenna, and is used for fixing the antenna structure, protecting the components, and providing stable mechanical performance to ensure electrical performance and reliability.

[0037] The above only describes the preferred embodiments of the present application, and is not used to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A dual-polarized electrically small antenna probe for the VHF band, characterized in that: The antenna includes a first linearly polarized matched dipole antenna unit (1) and a second linearly polarized matched dipole antenna unit (2). The first and second linearly polarized matched dipole antenna units have the same size and operating frequency. Both the first and second linearly polarized matched dipole antenna units include a PCB substrate (3), antenna copper sheets (4), a balun matching circuit (5), and an RF line (6). The PCB substrates of the first and second linearly polarized matched dipole antenna units are orthogonally spliced ​​to form a cross structure. Antenna copper sheets are printed on one end surface of the PCB substrates of the first and second linearly polarized matched dipole antenna units, and the antenna copper sheets on each PCB substrate are symmetrically arranged on the left and right sides along the orthogonal splicing line of the PCB substrate. Each PCB substrate has a balun matching circuit and an RF line. The two sets of antenna copper sheets on each PCB substrate are connected to the balun matching circuit through the RF line to achieve antenna input feeding.

2. The dual-polarized electrically small antenna probe for the VHF band according to claim 1, characterized in that: The first linear polarization matched dipole antenna unit has a first opening gap (7) formed in the middle of the lower end of the PCB substrate, and the second polarization matched dipole antenna unit has a second opening gap (8) formed in the middle of the upper end of the PCB substrate. The substrates of the first linear polarization matched dipole antenna unit and the second polarization matched dipole antenna unit are connected to form an orthogonal splicing structure through the first opening gap and the second opening gap.

3. The dual-polarized electrically small antenna probe for the VHF band according to claim 1, characterized in that: The PCB substrates of the first linear polarization matched dipole antenna unit and the second linear polarization matched dipole antenna unit are symmetrically printed with multiple antenna copper sheets on both sides of the orthogonal splicing line, and adjacent antenna copper sheets are connected in series through patch resistors (9).

4. The dual-polarized electrically small antenna probe for the VHF band according to claim 1, characterized in that: The operating frequencies of the first and second linearly polarized matched dipole antenna elements cover 50MHz to 400MHz. The dimensions of the first and second linearly polarized matched dipole antenna elements are: length 380mm and width 240mm.

5. The dual-polarized electrically small antenna probe for the VHF band according to claim 1, characterized in that: The first and second linearly polarized matched dipole antenna elements use Taconic RF35 as the dielectric of the PCB substrate. The dielectric has a layer thickness of 0.76 mm, a dielectric constant of 3.5 ± 0.05, and a loss factor of 0.0018 at 10 GHz.

6. The dual-polarized electrically small antenna probe for the VHF band according to claim 1, characterized in that: The PCB substrate is covered with an antenna copper sheet on one side, and the antenna copper sheet is made of copper foil with a thickness of 35μm.

7. The dual-polarized electrically small antenna probe for the VHF band according to claim 1, characterized in that: The radio frequency line is provided with a magnetic ring (10) for suppressing high-frequency interference and optimizing signal transmission performance.

8. The dual-polarized electrically small antenna probe for the VHF band according to claim 1, characterized in that: The first linearly polarized matched dipole antenna unit and the second linearly polarized matched dipole antenna unit also include an RG174 coaxial cable (11). The inner core wire and shielding mesh wire at one end of the RG174 coaxial cable are soldered to the balun impedance adapter of the balun matching circuit to achieve connection and conduction with the balun matching circuit. The other end of the RG174 coaxial cable forms the feed port (12) of the first linearly polarized matched dipole antenna unit and the second linearly polarized matched dipole antenna unit.

9. The dual-polarized electrically small antenna probe for the VHF band according to claim 1, characterized in that: One end of the inner core wire of the RF cable is soldered to the pin of the impedance adapter of the balun matching circuit, and the other end of the inner core wire of the RF cable is soldered to the printed circuit terminal formed by the antenna copper sheet printed on the surface of the PCB substrate. The shielding mesh of the RF cable is soldered to the grounding pad of the impedance adapter to achieve reliable signal transmission and stable electrical performance.

10. The dual-polarized electrically small antenna probe for the VHF band according to claim 5, characterized in that: It is also provided with a non-metallic shell (13), in which the first linearly polarized matched dipole antenna unit and the second linearly polarized matched dipole antenna unit are fixedly installed, and the non-metallic shell positions and protects the first linearly polarized matched dipole antenna unit and the second linearly polarized matched dipole antenna unit.

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