A VHF / UHF dual-band high-gain omnidirectional antenna and method of use thereof

Abstract

The application belongs to the field of omnidirectional antennas, and discloses a VHF / UHF dual-frequency high-gain omnidirectional antenna and a use method thereof, which comprises a VHF whip antenna, the VHF whip antenna comprising a VHF slotted upper dipole, a VHF lower dipole, a VHF matching sleeve, a VHF impedance matching network and a first feeding cable for feeding the VHF frequency band; and a UHF dipole array antenna, the UHF dipole array antenna being nested on the outer periphery of the VHF lower dipole to realize structural multiplexing, the UHF dipole array antenna comprising a first UHF dipole, a second UHF dipole and a third UHF dipole which are arranged at intervals along the axial direction, and a second feeding cable for feeding the UHF frequency band. The scheme realizes independent operation of the dual frequency bands, high-gain omnidirectional radiation and strong anti-platform interference capability under a compact structure by integrally designing the VHF whip antenna and the UHF three-dipole array antenna which is nested on the outer periphery of the lower dipole of the VHF whip antenna, and cooperating with independent double-path feeding and a choke magnetic ring series.

Description

Technical Field

[0001] This invention relates to the field of omnidirectional antennas, and more particularly to a VHF / UHF dual-band high-gain omnidirectional antenna and its usage method. Background Technology

[0002] In today's high-tech military field, VHF and UHF omnidirectional antennas are widely used. Common antenna structures for VHF / UHF omnidirectional antennas include whip antennas, cage antennas, and conical antennas. Whip antennas, in particular, are widely used in VHF vehicle-mounted communication. Typically, a whip antenna consists of a monopole or symmetrical dipole and a broadband matching network. The broadband matching network is generally composed of a matching circuit consisting of lumped components such as resistors, capacitors, inductors, and transformers. Its high loss results in low antenna gain and limited power capacity, failing to meet the requirements of high-power, high-gain applications.

[0003] Therefore, this solution proposes a VHF / UHF dual-band high-gain omnidirectional antenna and its usage method. Summary of the Invention

[0004] The present invention aims to provide a VHF / UHF dual-band high-gain omnidirectional antenna and its usage method to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A VHF / UHF dual-band high-gain omnidirectional antenna includes: a VHF whip antenna, wherein the VHF whip antenna includes a VHF slotted upper element, a VHF lower element, a VHF matching sleeve, a VHF impedance matching network, and a first feed cable for feeding the VHF band. The UHF vibrator array antenna is nested around the outer periphery of the VHF vibrator to achieve structural reuse. The UHF vibrator array antenna includes a first UHF vibrator, a second UHF vibrator, and a third UHF vibrator spaced apart along the axial direction, as well as a second feed cable for feeding the UHF band. The first feeder cable and the second feeder cable are set independently of each other. The first feeder cable is fitted with a first choke magnetic ring string, and the second feeder cable is fitted with a second choke magnetic ring string. It also includes an antenna mounting base.

[0006] Preferably, the VHF impedance matching network is a passive two-port network; its lower branch is a ground common branch, and its upper branch is connected in series with a resistor R1, a first inductor L1 and a second inductor L2 from the positive terminal of the input terminal to the positive terminal of the output terminal. One end of capacitor C1 is connected to the midpoint between the first inductor L1 and the second inductor L2, and the other end is connected to the grounding common branch; The first inductor L1, the second inductor L2, and the capacitor C1 form a low-pass filter topology, which is used to suppress the passage of signals above the VHF operating frequency band and transmit frequency band signals; the resistor R1 is a damping resistor, which is used to suppress LC resonance spikes, broaden the impedance matching bandwidth, and reduce in-band standing wave fluctuations.

[0007] Preferably, the broadband impedance matching of the VHF whip antenna is achieved by the VHF impedance matching network and the VHF matching sleeve working together; The VHF impedance matching network is a lumped parameter matching circuit, and the VHF matching sleeve is a distributed parameter matching structure. The combination of the two achieves stable broadband matching with low loss and high power capacity in the 30MHz to 88MHz frequency band.

[0008] Preferably, the UHF dipole array antenna further includes three equal-amplitude, in-phase UHF power dividers; The second feed cable is connected to the input terminal of the UHF power divider. The three output terminals of the UHF power divider are respectively connected one-to-one to the first UHF oscillator, the second UHF oscillator, and the third UHF oscillator through the first branch feed cable, the second branch feed cable, and the third branch feed cable, so as to realize equal amplitude and in-phase feeding of the three sets of UHF oscillators.

[0009] Preferably, the first choke magnetic ring string is fitted onto the cable segment of the first feed cable near the antenna mounting base, and the second choke magnetic ring string is fitted onto the cable segment of the second feed cable near the antenna mounting base; the first choke magnetic ring string and the second choke magnetic ring string are used to suppress the longitudinal surface current on the outer surface of the feed cable, so as to reduce the influence of the ground or vehicle-mounted mounting platform on the antenna input impedance and radiation pattern.

[0010] Preferably, it also includes a two-end docking structure, which is located in the middle of the VHF whip antenna and is used to split the entire antenna into upper and lower sections, while realizing the mechanical structure docking and radio frequency electrical signal connection between the two sections.

[0011] Preferably, the resistor R1 is a power damping resistor with a resistance range of 10Ω to 100Ω; the inductance values ​​of the first inductor L1 and the second inductor L2 are both in the range of 50nH to 200nH; and the capacitance value of the capacitor C1 is in the range of 10pF to 100pF.

[0012] Preferably, the VHF band operates in the frequency range of 30MHz to 88MHz and uses symmetrical dipole whip radiation; the UHF band operates in the frequency range of 540MHz to 680MHz and uses a three-dipole array radiation; the VHF band and the UHF band are independently fed and operate independently.

[0013] Preferably, it also includes an antenna cover, a shock-absorbing spring, and an antenna mounting base; the shock-absorbing spring is located between the bottom of the VHF whip antenna and the antenna mounting base, and the antenna cover covers the outside of the VHF whip antenna and the UHF vibrator array antenna to achieve waterproof protection.

[0014] The method of using the VHF / UHF dual-band high-gain omnidirectional antenna was also disclosed, including VHF band transmission mode, VHF band reception mode, UHF band transmission mode and UHF band reception mode; VHF band transmission mode: The VHF band electromagnetic wave signal is fed into the VHF impedance matching network through the first feed cable, and after being matched by the VHF impedance matching network, it is fed into the VHF slotted upper vibrator and the VHF lower vibrator, and the VHF band electromagnetic wave is radiated into free space by the VHF whip antenna; the first choke magnetic ring string suppresses the longitudinal current on the outer surface of the first feed cable, reducing the influence of the mounting platform on the antenna impedance and radiation pattern; VHF band reception mode: The VHF whip antenna senses VHF band electromagnetic waves in free space, which are then transformed by the VHF impedance matching network and the VHF matching sleeve, and output to the back-end receiving system through the first feed cable. UHF band transmission mode: The UHF band electromagnetic wave signal is fed into the UHF power divider via the second feed cable. After being divided into three paths by the UHF power divider with equal amplitude and in phase, the signals are fed into the first UHF vibrator, the second UHF vibrator, and the third UHF vibrator respectively via the first branch feed cable, the second branch feed cable, and the third branch feed cable. The UHF vibrator array antenna then radiates UHF band electromagnetic waves into free space. The second choke magnetic ring string suppresses the longitudinal current on the outer surface of the second feed cable, reducing the influence of the mounting platform on the antenna impedance and radiation pattern. UHF band reception mode: The first UHF vibrator, the second UHF vibrator, and the third UHF vibrator in the UHF vibrator array antenna respectively sense UHF band electromagnetic waves in free space, and are fed into the UHF power divider via the first branch feed cable, the second branch feed cable, and the third branch feed cable for equal amplitude and in-phase synthesis, and then output to the back-end receiving system via the second feed cable.

[0015] The beneficial effects of this technical solution compared to existing technologies are as follows: (1) This invention integrates a VHF whip antenna and a UHF dipole array antenna nested around the VHF dipole, forming a structure that is multiplexed and integrated. Combined with a dual-path feeding system that is independent of the VHF and UHF bands, and a choke magnetic ring string mounted on the two feed cables to effectively suppress the longitudinal current on the outer surface of the cable, it realizes the dual-band high-gain omnidirectional radiation function of integrating the VHF symmetrical dipole whip antenna and the UHF three-dipole array antenna in the same radome. The VHF and UHF bands can work independently without interference. At the same time, the choke magnetic ring string reduces the distortion of the antenna input impedance and radiation pattern on the ground or vehicle-mounted installation platform. It has the advantages of compact structure, wide bandwidth, high gain, large power capacity and strong anti-environmental interference capability, which can fully meet the high-performance application requirements of vehicle-mounted UHF dual-band antennas in the field of military communications. Attached Figure Description

[0016] Figure 1 This is a cross-sectional view of the internal structure of the present invention; Figure 2 A partial structural view provided for this invention; Figure 3 A schematic diagram of the connection between the feeder cable and the choke magnetic ring provided by the present invention; Figure 4 This is a schematic diagram showing the connection between the UHF vibrator and the branch feed cable provided by the present invention; Figure 5 This is a schematic diagram of the VHF impedance matching network topology provided by the present invention; Reference numerals in the attached diagram: 1. VHF whip antenna; 2. UHF vibrator array antenna; 3. Radome; 4. Shock-absorbing spring; 5. Antenna mounting base; 6. VHF slotted upper vibrator; 7. VHF lower vibrator; 8. VHF matching sleeve; 9. VHF impedance matching network; 10. Two-end docking structure; 11. First feed cable; 12. First choke magnetic ring string; 13. First UHF vibrator; 14. Second UHF vibrator; 15. Third UHF vibrator; 16. First branch feed cable; 17. Second branch feed cable; 18. Third branch feed cable; 19. UHF power divider; 20. Second feed cable; 21. Second choke magnetic ring string; Detailed Implementation

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments: like Figure 1As shown, the present invention provides a VHF / UHF dual-band high-gain omnidirectional antenna, mainly comprising a VHF whip antenna 1 and a UHF dipole array antenna 2. The VHF whip antenna 1 is used to achieve signal radiation and reception in the VHF band (30MHz~88MHz), and the UHF dipole array antenna 2 is used to achieve signal radiation and reception in the UHF band (540MHz~680MHz). The VHF whip antenna 1 and the UHF dipole array antenna 2 adopt an integrated design with structural reuse, both located on the same axis. The entire antenna is covered by an antenna cover 3, and a shock-absorbing spring 4 and an antenna mounting base 5 are sequentially arranged at the bottom of the antenna.

[0018] like Figure 2 As shown, the VHF whip antenna 1 includes a VHF slotted upper dipole 6, a VHF lower dipole 7, a VHF matching sleeve 8, a VHF impedance matching network 9, and a first feed cable 11 for feeding the VHF band. The VHF slotted upper dipole 6 and the VHF lower dipole 7 together constitute a symmetrical dipole radiator for the VHF band. The VHF slotted upper dipole 6 is located at the top of the antenna, and its surface has several axial slots to adjust the equivalent electrical length of the dipole, thereby extending the operating bandwidth of the VHF band. The VHF lower dipole 7 is located in the lower middle part of the antenna and is electrically connected to the VHF slotted upper dipole 6.

[0019] The VHF matching sleeve 8 is fitted around the outer periphery of the VHF lower vibrator 7 or placed near the feed end of the VHF whip antenna 1, serving as a distributed parameter matching structure. A coaxial transmission line structure is formed between the VHF matching sleeve 8 and the VHF lower vibrator 7. By adjusting the sleeve's length, inner diameter, and the gap distance between it and the vibrator, the input impedance of the antenna can be initially transformed within a certain frequency band, creating favorable conditions for subsequent lumped parameter matching.

[0020] VHF impedance matching network 9, the specific circuit topology is as follows: Figure 5 As shown. The VHF impedance matching network 9 is a passive two-port network. Its lower branch is a common ground branch, and its upper branch has a resistor R1, a first inductor L1, and a second inductor L2 connected in series from the positive input terminal to the positive output terminal. One end of the capacitor C1 is connected to the midpoint between the first inductor L1 and the second inductor L2, and the other end is connected to the common ground branch.

[0021] In this design, the first inductor L1, the second inductor L2, and the capacitor C1 form a low-pass filter topology to suppress signals above the VHF operating frequency band while transmitting VHF signals in the 30MHz to 88MHz range. Resistor R1 is a power-type damping resistor, preferably with a resistance range of 10Ω to 100Ω, used to suppress LC resonance spikes, broaden the impedance matching bandwidth, and reduce in-band standing wave ripple. The inductance values ​​of both the first inductor L1 and the second inductor L2 are preferably in the range of 50nH to 200nH, and the capacitance value of capacitor C1 is preferably in the range of 10pF to 100pF. The specific values ​​of these components can be determined through simulation optimization based on the input impedance characteristics of the actual antenna.

[0022] The broadband impedance matching of the VHF whip antenna 1 is achieved collaboratively by the VHF impedance matching network 9 and the VHF matching sleeve 8. The VHF impedance matching network 9 is a lumped parameter matching circuit, and the VHF matching sleeve 8 is a distributed parameter matching structure. Together, they achieve stable broadband matching with low loss and high power capacity within the 30MHz–88MHz frequency band. In practice, the bare radiator of the VHF whip antenna 1 can first be modeled using three-dimensional electromagnetic simulation software (such as HFSS) to obtain its input impedance as a function of frequency. Then, the dimensional parameters of the VHF matching sleeve 8 are designed based on this impedance data. Finally, the component parameters of the VHF impedance matching network 9 are designed to perform fine-grained impedance compensation throughout the entire frequency band, ensuring that the voltage standing wave ratio (VSWR) meets the design requirements across the entire frequency band.

[0023] like Figure 1 and Figure 4 As shown, the UHF vibrator array antenna 2 is nested around the VHF lower vibrator 7 to achieve structural reuse. The UHF vibrator array antenna 2 includes a first UHF vibrator 13, a second UHF vibrator 14, and a third UHF vibrator 15 spaced apart along the axial direction, and a second feed cable 20 for powering the UHF band. The three UHF vibrators are arranged at equal or unequal intervals along the axial direction, and each vibrator is a symmetrical vibrator. Its length is determined according to the center frequency of the UHF band, typically about half a wavelength. All three UHF vibrators are nested around the VHF lower vibrator 7, maintaining an insulating gap between them to achieve structural reuse without generating electrical interference.

[0024] The UHF dipole array antenna 2 also includes a three-way equal-amplitude and in-phase UHF power divider 19. A second feed cable 20 connects to the input of the UHF power divider 19. The three outputs of the UHF power divider 19 are connected one-to-one to the first UHF dipole 13, the second UHF dipole 14, and the third UHF dipole 15 via the first branch feed cable 16, the second branch feed cable 17, and the third branch feed cable 18, respectively, achieving equal-amplitude and in-phase feeding for the three sets of UHF dipoles. The UHF power divider 19 can be a microstrip power divider, a coaxial power divider, or a lumped-parameter power divider. Internally, it includes an impedance transformation section and isolation resistors to ensure that the amplitude imbalance between the three output ports is less than 0.5 dB and the phase imbalance is less than 5°.

[0025] The first feed cable 11 and the second feed cable 20 are independently installed, both introduced from the antenna mounting base 5 and extending upwards along the inside of the antenna to their respective feed points. The first feed cable 11 is used to transmit VHF band radio frequency signals, and the second feed cable 20 is used to transmit UHF band radio frequency signals. The two feed cables are routed independently and do not interfere with each other.

[0026] like Figure 3 As shown, a first choke magnetic ring string 12 is fitted onto the first feed cable 11, and a second choke magnetic ring string 21 is fitted onto the second feed cable 20. The first choke magnetic ring string 12 is fitted onto the cable segment of the first feed cable 11 near the antenna mounting base 5, and the second choke magnetic ring string 21 is fitted onto the cable segment of the second feed cable 20 near the antenna mounting base 5. Each choke magnetic ring string consists of several high-frequency ferrite magnetic rings arranged sequentially along the cable axis. The inner diameter of the magnetic ring matches the outer diameter of the cable, ensuring that the magnetic ring can be tightly fitted onto the outer conductor of the cable.

[0027] The first choke magnetic ring string 12 and the second choke magnetic ring string 21 are used to suppress the longitudinal surface current (i.e., common-mode current) on the outer surface of the feed cable, thereby reducing the impact of the ground or vehicle-mounted mounting platform on the antenna's input impedance and radiation pattern. Specifically, when the radio frequency signal is transmitted along the feed cable, a longitudinal current is induced on the outer surface of the cable's outer conductor. This current flows along the cable's outer surface to the mounting platform, making the mounting platform part of the antenna radiator, thus altering the antenna's impedance characteristics and radiation pattern. The choke magnetic ring string forms a high-frequency choke coil on the cable's outer surface, presenting high impedance to the common-mode current, effectively blocking its flow and achieving radio frequency isolation between the antenna and the mounting platform.

[0028] like Figure 1 As shown, the present invention also includes a two-end docking structure 10, which is located in the middle of the VHF whip antenna 1 and is used to split the overall antenna into upper and lower sections, while realizing the mechanical structure docking and radio frequency electrical signal connection between the two sections.

[0029] In practical implementation, the two-end docking structure 10 can adopt a threaded connection plus a coaxial pin. The bottom of the upper antenna section is provided with an internal thread and a central insertion hole, while the top of the lower antenna section is provided with an external thread and a central insertion pin. When the upper and lower sections are screwed together, the central insertion pin is inserted into the central insertion hole, realizing the radio frequency electrical signal connection between the VHF slotted upper vibrator 6 and the VHF lower vibrator 7. At the same time, the threaded connection ensures the stability of the mechanical structure. A sealing ring can also be provided on the outer periphery of the two-end docking structure 10 to ensure the waterproof sealing performance of the docking point. The design of this two-end docking structure 10 facilitates the transportation, installation, and maintenance of the antenna, reducing the difficulty of packaging and transporting the overall antenna.

[0030] like Figure 1 As shown, the present invention also includes an radome 3, a shock-absorbing spring 4, and an antenna mounting base 5. The radome 3 covers the exterior of the VHF whip antenna 1 and the UHF dipole array antenna 2 to achieve waterproof protection. The radome 3 is made of fiberglass or polycarbonate (PC) material with good wave transmission performance, and its wall thickness is determined comprehensively based on the requirements of mechanical strength and wave transmission rate, typically 2mm to 5mm. The bottom of the radome 3 is sealed to the antenna mounting base 5 with sealant or a sealing ring for waterproofing.

[0031] A shock-absorbing spring 4 is located between the bottom of the VHF whip antenna 1 and the antenna mounting base 5. The shock-absorbing spring 4 is a helical metal spring, with its upper and lower ends fixedly connected to the bottom of the VHF whip antenna 1 and the antenna mounting base 5, respectively. The shock-absorbing spring 4 acts as a buffer when the antenna is subjected to vibrations and impacts during vehicle operation, protecting the radiators and feed network inside the antenna from mechanical damage. Simultaneously, the metal spring body of the shock-absorbing spring 4 can also serve as part of the grounding of the VHF whip antenna 1, participating in the antenna's radio frequency grounding.

[0032] The antenna mounting base 5 is fixed to the top of the vehicle or other mounting platform. The base is provided with mounting holes and RF cable lead-out interfaces. The first feed cable 11 and the second feed cable 20 are led out from inside the antenna and pass through the cable lead-out interfaces of the antenna mounting base 5 to connect to the transceiver at the rear end.

[0033] Detailed implementation of antenna usage method The VHF / UHF dual-band high-gain omnidirectional antenna of this invention has four operating modes: VHF band transmission mode, VHF band reception mode, UHF band transmission mode, and UHF band reception mode. These four modes can be switched independently according to actual communication needs without interference.

[0034] VHF Band Transmission Mode: When the system is in VHF band transmission mode, the VHF band electromagnetic wave signal is fed from the bottom into the VHF impedance matching network 9 via the first feed cable 11. The signal first passes through the impedance matching network composed of resistor R1, first inductor L1, second inductor L2, and capacitor C1, undergoing impedance transformation and low-pass filtering to remove high-frequency spurious signals. The matched signal is then fed into the VHF slotted upper dipole 6 and VHF lower dipole 7, and radiated into free space by the VHF whip antenna 1. During this process, the first choke magnetic ring string 12 suppresses the longitudinal current on the outer surface of the first feed cable 11, preventing the cable's outer surface from becoming a parasitic radiator, reducing the impact of the mounting platform on the antenna impedance and radiation pattern, and ensuring that the VHF band radiation pattern maintains omnidirectional characteristics.

[0035] VHF Band Reception Mode: When the system is in VHF band reception mode, the VHF slotted upper vibrator 6 and VHF lower vibrator 7 of the VHF whip antenna 1 induce VHF band electromagnetic waves in free space, generating an induced electromotive force on the vibrators. This induced signal undergoes preliminary distributed parameter impedance transformation via the VHF matching sleeve 8, and is then sent to the VHF impedance matching network 9 for further impedance matching and filtering. Finally, it is output to the downstream VHF receiving system via the first feed cable 11.

[0036] UHF Band Transmission Mode: When the system is in UHF band transmission mode, the UHF band electromagnetic wave signal is fed into the UHF power divider 19 via the second feed cable 20. The UHF power divider 19 distributes the input RF signal into three paths with equal amplitude and in phase. These three signals are fed into the first UHF vibrator 13, the second UHF vibrator 14, and the third UHF vibrator 15 via the first branch feed cable 16, the second branch feed cable 17, and the third branch feed cable 18, respectively. The three UHF vibrators radiate simultaneously with equal amplitude and in phase, forming an omnidirectional radiation pattern in the horizontal plane and an array composite radiation pattern in the vertical plane, thereby achieving high-gain omnidirectional radiation in the UHF band. During this process, the second choke magnetic ring string 21 suppresses the longitudinal current on the outer surface of the second feed cable 20, reducing the impact of the mounting platform on the antenna impedance and radiation pattern.

[0037] UHF Band Reception Mode: When the system is in UHF band reception mode, the first UHF vibrator 13, the second UHF vibrator 14, and the third UHF vibrator 15 in the UHF vibrator array antenna 2 respectively induce UHF band electromagnetic waves in free space, generating induced electromotive force on each vibrator. The three received signals are fed into the UHF power divider 19 via the first branch feed cable 16, the second branch feed cable 17, and the third branch feed cable 18, respectively. The UHF power divider 19 performs equal-amplitude and in-phase combining, and the combined signal is output to the downstream UHF receiving system via the second feed cable 20.

[0038] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A VHF / UHF dual-band high-gain omnidirectional antenna, characterized in that, include: VHF whip antenna (1), the VHF whip antenna (1) includes a VHF slotted upper element (6), a VHF lower element (7), a VHF matching sleeve (8), a VHF impedance matching network (9), and a first feed cable (11) for feeding the VHF band. UHF vibrator array antenna (2), which is nested around the outer periphery of the VHF lower vibrator (7) to achieve structural reuse, the UHF vibrator array antenna (2) includes a first UHF vibrator (13), a second UHF vibrator (14) and a third UHF vibrator (15) spaced apart along the axial direction, and a second feed cable (20) for feeding the UHF band. The first feed cable (11) and the second feed cable (20) are set independently of each other. The first feed cable (11) is fitted with a first choke magnetic ring string (12), and the second feed cable (20) is fitted with a second choke magnetic ring string (21). It also includes an antenna mounting base (5).

2. The VHF / UHF dual-band high-gain omnidirectional antenna as described in claim 1, characterized in that, The VHF impedance matching network (9) is a passive two-port network; its lower branch is a ground common branch, and its upper branch is connected in series with resistor R1, first inductor L1 and second inductor L2 from the positive terminal of the input terminal to the positive terminal of the output terminal. One end of capacitor C1 is connected to the midpoint between the first inductor L1 and the second inductor L2, and the other end is connected to the grounding common branch; The first inductor L1, the second inductor L2, and the capacitor C1 form a low-pass filter topology, which is used to suppress the passage of signals above the VHF operating frequency band and transmit VHF frequency band signals; the resistor R1 is a damping resistor, which is used to suppress LC resonance spikes, broaden the impedance matching bandwidth, and reduce in-band standing wave fluctuations.

3. The VHF / UHF dual-band high-gain omnidirectional antenna as described in claim 2, characterized in that, The broadband impedance matching of the VHF whip antenna (1) is achieved by the VHF impedance matching network (9) and the VHF matching sleeve (8) working together. The VHF impedance matching network (9) is a lumped parameter matching circuit, and the VHF matching sleeve (8) is a distributed parameter matching structure. The combination of the two achieves stable broadband matching with low loss and high power capacity in the 30MHz to 88MHz frequency band.

4. The VHF / UHF dual-band high-gain omnidirectional antenna as described in claim 1, characterized in that, The UHF vibrator array antenna (2) also includes three equal-amplitude and in-phase UHF power dividers (19). The second feed cable (20) is connected to the input terminal of the UHF power divider (19). The three output terminals of the UHF power divider (19) are respectively connected to the first UHF oscillator (13), the second UHF oscillator (14), and the third UHF oscillator (15) one-to-one through the first branch feed cable (16), the second branch feed cable (17), and the third branch feed cable (18), so as to realize the equal amplitude and phase feeding of the three sets of UHF oscillators.

5. A VHF / UHF dual-band high-gain omnidirectional antenna as described in claim 1, characterized in that, The first choke magnetic ring string (12) is fitted onto the cable segment of the first feed cable (11) near the antenna mounting base (5), and the second choke magnetic ring string (21) is fitted onto the cable segment of the second feed cable (20) near the antenna mounting base (5); the first choke magnetic ring string (12) and the second choke magnetic ring string (21) are used to suppress the longitudinal surface current on the outer surface of the feed cable, so as to reduce the influence of the ground or vehicle mounting platform on the antenna input impedance and radiation pattern.

6. A VHF / UHF dual-band high-gain omnidirectional antenna as described in claim 1, characterized in that, It also includes a two-end docking structure (10), which is located in the middle of the VHF whip antenna (1) and is used to split the entire antenna into upper and lower sections, while realizing the mechanical structure docking and radio frequency electrical signal connection between the two sections.

7. A VHF / UHF dual-band high-gain omnidirectional antenna as described in claim 2, characterized in that, The resistor R1 is a power damping resistor with a resistance range of 10Ω to 100Ω; the inductance values ​​of the first inductor L1 and the second inductor L2 are both in the range of 50nH to 200nH; and the capacitance value of the capacitor C1 is in the range of 10pF to 100pF.

8. A VHF / UHF dual-band high-gain omnidirectional antenna as described in claim 1, characterized in that, The VHF band operates in the frequency range of 30MHz to 88MHz and uses symmetrical dipole whip radiation; the UHF band operates in the frequency range of 540MHz to 680MHz and uses a three-dipole array radiation; the VHF band and the UHF band are independently fed and operate independently.

9. A VHF / UHF dual-band high-gain omnidirectional antenna as described in claim 1, characterized in that, It also includes an antenna cover (3), a shock-absorbing spring (4) and an antenna mounting base (5); the shock-absorbing spring (4) is located between the bottom of the VHF whip antenna (1) and the antenna mounting base (5), and the antenna cover (3) covers the outside of the VHF whip antenna (1) and the UHF vibrator array antenna (2) to achieve waterproof protection.

10. The method of using the VHF / UHF dual-band high-gain omnidirectional antenna according to any one of claims 1 to 9, characterized in that, This includes VHF band transmit mode, VHF band receive mode, UHF band transmit mode, and UHF band receive mode; VHF band transmission mode: VHF band electromagnetic wave signals are fed into the VHF impedance matching network (9) via the first feed cable (11), and after being matched by the VHF impedance matching network (9), they are fed into the VHF slotted upper vibrator (6) and the VHF lower vibrator (7), and the VHF band electromagnetic waves are radiated into free space by the VHF whip antenna (1); the first choke magnetic ring string (12) suppresses the longitudinal current on the outer surface of the first feed cable (11) and reduces the influence of the mounting platform on the antenna impedance and radiation pattern; VHF band receiving mode: The VHF whip antenna (1) senses VHF band electromagnetic waves in free space, and after impedance transformation by the VHF impedance matching network (9) and the VHF matching sleeve (8), the waves are output to the back-end receiving system by the first feed cable (11). UHF band transmission mode: The UHF band electromagnetic wave signal is fed into the UHF power divider (19) via the second feed cable (20). After being divided into three paths by the UHF power divider (19) with equal amplitude and in phase, the signals are fed into the first UHF vibrator (13), the second UHF vibrator (14), and the third UHF vibrator (15) via the first branch feed cable (16), the second branch feed cable (17), and the third branch feed cable (18), respectively. The UHF vibrator array antenna (2) radiates UHF band electromagnetic waves into free space. The second choke magnetic ring string (21) suppresses the longitudinal current on the outer surface of the second feed cable (20) and reduces the influence of the installation platform on the antenna impedance and radiation pattern. UHF band receiving mode: The first UHF vibrator (13), the second UHF vibrator (14) and the third UHF vibrator (15) in the UHF vibrator array antenna (2) respectively sense UHF band electromagnetic waves in free space, and are fed into the UHF power divider (19) through the first branch feed cable (16), the second branch feed cable (17) and the third branch feed cable (18) respectively for equal amplitude and in phase synthesis, and output to the back-end receiving system through the second feed cable (20).

Images