A quad-like helix antenna

Abstract

The application relates to the technical field of antennas, in particular to a kind of four-arm spiral antenna. Four-arm spiral antenna includes ground plate, active radiation arm, passive radiation arm, active radiation arm and passive radiation arm are connected on ground plate respectively, active radiation arm feeds into differential signal to generate antenna resonance, passive radiation arm is coupled from active radiation arm of differential signal feed to generate parasitic resonance, two active radiation arms and two passive radiation arms are arranged in turn around the spiral symmetry structure of antenna center area, the parasitic resonance frequency of passive radiation arm deviates from the antenna resonance frequency of active radiation arm. The antenna structure significantly simplifies the feed structure, greatly reduces the manufacturing complexity and cost, while realizing high port isolation and stable circular polarization performance in compact layout.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of antennas, in particular to a kind of four-arm spiral antenna. BACKGROUND

[0002] With the rapid development of wireless communication and satellite navigation technology, there is an increasing demand for high-performance, miniaturized antennas. In particular, in the fields of global navigation satellite system (GNSS), unmanned aerial vehicle communication, vehicle positioning system and Internet of Things (IoT), antennas need to have stable radiation characteristics and achieve efficient signal transmission under space constraints. To improve the reliability and anti-interference capability of the system, circularly polarized antennas are the preferred solution for such scenarios due to their excellent polarization matching and anti-multipath effect characteristics. Among them, four-arm spiral antennas, as a typical circularly polarized antenna, have attracted widespread attention in the above applications due to their wideband characteristics and high gain performance. However, the design of traditional four-arm spiral antennas still faces many challenges.

[0003] Existing technologies usually rely on four independent radiation arms and corresponding feed ports to achieve circularly polarized radiation. Each radiation arm needs to introduce a differential signal with a phase difference of 90 degrees through a complex power division network and matching circuit to form a uniform circularly polarized wave. However, this multi-port design and its related circuits significantly increase the design complexity and manufacturing cost of the antenna, making it difficult to integrate into miniaturized devices. Another self-phase method generates a phase difference through the geometric symmetry of the radiation arm to achieve circular polarization, but it requires very high processing precision and is prone to reduced port isolation and degraded polarization performance under non-ideal orthogonal conditions, limiting its adaptability in complex environments.

[0004] To overcome the above problems, existing technologies have proposed some improvement schemes. For example, some designs attempt to reduce the number of feed ports to achieve circular polarization, but often result in limited bandwidth or decreased gain, making it difficult to meet the requirements of multi-band and high-precision applications. Other schemes reduce the size by adjusting the geometric shape of the radiation arm or adding dielectric loading, but usually come with a loss of radiation efficiency or a decrease in design flexibility. Overall, traditional four-arm spiral antennas are difficult to achieve an effective balance between miniaturization, low cost and high performance, especially in modern communication systems where integration requirements are high, and their application is significantly limited. SUMMARY

[0005] The present application provides a kind of four-arm spiral antenna, aims at simplifying the feed structure, greatly reduces manufacturing complexity and cost, while realizing high port isolation and stable circular polarization performance in compact layout.

[0006] The application provides a kind of four-arm-like spiral antenna, including ground plate, active radiation arm, passive radiation arm, the active radiation arm and passive radiation arm are connected on ground plate respectively, the active radiation arm feeds into differential signal to generate antenna resonance, the passive radiation arm is coupled from the active radiation arm of feeding differential signal to generate parasitic resonance, two the active radiation arm and two the passive radiation arm are sequentially arranged in spiral symmetry structure around antenna center area, the parasitic resonance frequency of the passive radiation arm deviates from the antenna resonance frequency of the active radiation arm.

[0007] As a further improvement of the application, two the active radiation arm uses the combination of equal electrical length or the combination of unequal electrical length, two the passive radiation arm uses the combination of equal electrical length or the combination of unequal electrical length, the electrical length of the active radiation arm is one of λ 0 / 4 or its odd multiple, λ 0 / 2 or its integer multiple, the electrical length of the passive radiation arm is one of deviating from λ 0 / 4 or its odd multiple, deviating from λ 0 / 2 or its integer multiple, wherein λ 0 is the wavelength of antenna operating frequency.

[0008] As a further improvement of the application, the active radiation arm includes first active radiation arm, second active radiation arm, the passive radiation arm includes first passive radiation arm, second passive radiation arm, one end of the first active radiation arm, second active radiation arm, first passive radiation arm, second passive radiation arm is connected on ground plate respectively, the first active radiation arm, second active radiation arm, first passive radiation arm, second passive radiation arm is sequentially arranged in spiral symmetry structure around antenna center area, the electrical length of the first active radiation arm and second active radiation arm is λ 0 / 4 or its odd multiple, the electrical length of the first passive radiation arm, second passive radiation arm deviates from λ 0 / 4 or its odd multiple;

[0009] Or the active radiation arm includes third active radiation arm, fourth active radiation arm, the passive radiation arm includes third passive radiation arm, fourth passive radiation arm, two ends of the third active radiation arm, fourth active radiation arm, third passive radiation arm, fourth passive radiation arm are connected on ground plate respectively, the third active radiation arm, fourth active radiation arm, third passive radiation arm, fourth passive radiation arm is sequentially arranged in spiral symmetry structure around antenna center area, the electrical length of the third active radiation arm and fourth active radiation arm is λ 0 / 2 or its integer multiple, the electrical length of the third passive radiation arm, fourth passive radiation arm deviates from λ 0 / 4 or its odd multiple.

[0010] As a further improvement of the application, four-arm-like spiral antenna further includes first capacitive element, the open end of the first active radiation arm, second active radiation arm, first passive radiation arm, second passive radiation arm is respectively connected with ground plate through first capacitive element.

[0011] As a further improvement of the present application, the quad-like helical antenna further comprises a first inductive element, one or more of the first active radiating arm, the second active radiating arm, the first passive radiating arm, the second passive radiating arm has one or both ends electrically connected to the ground plane through the first inductive element.

[0012] or one or both ends of the third active radiating arm, the fourth active radiating arm, the third passive radiating arm, the fourth passive radiating arm are electrically connected to the ground plane through the first inductive element.

[0013] As a further improvement of the present application, the active radiating arm and the passive radiating arm are each provided with a vertical radiating branch and a horizontal radiating branch, the vertical radiating branch is connected to the ground plane, and the horizontal radiating branch is connected to the vertical radiating branch and extends in a helical manner in the horizontal plane to form a low-profile antenna structure.

[0014] As a further improvement of the present application, the quad-like helical antenna further comprises a current branch for forming an additional current path, one or more of the active radiating arm and the passive radiating arm is connected with the current branch.

[0015] As a further improvement of the present application, the quad-like helical antenna further comprises an electromagnetic coupling branch for forming a spatial electromagnetic coupling, one or more of the active radiating arm and the passive radiating arm is provided with the electromagnetic coupling branch, and the electromagnetic coupling branch is arranged on one side of the active radiating arm and / or the passive radiating arm.

[0016] As a further improvement of the present application, the quad-like helical antenna further comprises a feed branch, the feed branch is arranged on one side of the active radiating arm, one end of the feed branch forms a coupling gap with the active radiating arm, and the other end of the feed branch is connected to a feed port.

[0017] As a further improvement of the present application, the quad-like helical antenna further comprises a feed branch, one end of the feed branch is connected to the active radiating arm, and the other end of the feed branch is connected to a feed port.

[0018] As a further improvement of the present application, the quad-like helical antenna further comprises a first element, one end of the feed branch is connected in series to the active radiating arm through the first element, and the first element is a capacitive element, an inductive element, or a combination of the two.

[0019] As a further improvement of the present application, the quad-like helical antenna further comprises a second element, the second element is connected in parallel on one side of the feed branch, and the second element is a capacitive element, an inductive element, or a combination of the two.

[0020] As a further improvement of the present application, the quad-like helical antenna further comprises a differential feed network and a radio frequency chip, the differential feed network is connected to the feed port, and the radio frequency chip is connected to the differential feed network.

[0021] As a further improvement of the present application, the quasi-four-arm helical antenna further comprises a matching network, a differential feed network, and a radio frequency chip, the active radiation arms are connected to the differential feed network through the matching network, and the radio frequency chip is connected to the differential feed network.

[0022] As a further improvement of the present application, the two active radiation arms are respectively fed with differential signals with a phase difference of 90 degrees.

[0023] As a further improvement of the present application, the active radiation arms fed with the differential signals generate an antenna resonant operating frequency f0, the passive radiation arms generate a parasitic resonant operating frequency f1, and the frequency difference between f0 and f1 is controlled within ±20% of f0.

[0024] As a further improvement of the present application, the minimum spacing between each radiation arm is less than 0.05λ0, and λ0 is the wavelength of the operating frequency of the antenna.

[0025] The present application also provides an electronic device comprising the quasi-four-arm helical antenna.

[0026] The present application has the following beneficial effects:

[0027] The quasi-four-arm helical antenna is functionally similar to a conventional four-arm helical antenna and can achieve equivalent circularly polarized radiation characteristics, but by adopting a combined structure of two active radiation arms and two passive radiation arms, differential signal input and circular polarization modulation can be completed using only two feed ports. Compared with the design of a conventional four-arm helical antenna relying on a complex four-port feed network, the antenna structure significantly simplifies the feed structure, greatly reduces the manufacturing complexity and cost, and simultaneously realizes high port isolation and stable circular polarization performance in a compact layout.

[0028] In addition, through the parasitic resonance effect introduced by the passive radiation arms, the antenna structure optimizes the energy distribution between the two active radiation arms, ensures the symmetry and uniformity of the radiation pattern, and improves the design flexibility. This quasi-four-arm helical antenna provides a new solution for miniaturized and high-efficiency circularly polarized antennas, and is particularly suitable for high-demand application scenarios such as GNSS, satellite communication, and the next generation of wireless communication systems (such as 6G). BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a perspective structural schematic diagram of the quasi-four-arm helical antenna in Embodiment One of the present application;

[0030] Figure 2 is a planar development diagram of the quasi-four-arm helical antenna along the z-axis in Embodiment One of the present application;

[0031] Figure 3is the current distribution diagram of the class four-arm spiral antenna in the embodiment one of the application;

[0032] Figure 4 is the working principle schematic diagram of the differential feed in the embodiment one of the application;

[0033] Figure 5 is the equivalent circuit diagram of the class four-arm spiral antenna in the embodiment one of the application;

[0034] Figure 6 is the planar development diagram of the class four-arm spiral antenna along z axis in the embodiment two of the application;

[0035] Figure 7 is the current distribution diagram of the class four-arm spiral antenna in the embodiment two of the application;

[0036] Figure 8 is the three-dimensional structure diagram of the low profile class four-arm spiral antenna in the embodiment three of the application;

[0037] Figure 9 is the development diagram of the low profile class four-arm spiral antenna in the embodiment three of the application in xy plane;

[0038] Figure 10 is the planar development diagram of the low profile class four-arm spiral antenna along z axis in the embodiment three of the application;

[0039] Figure 11 is the U-shaped radiation arm structure schematic diagram in the embodiment four of the application;

[0040] Figure 12 is the radiation arm schematic diagram loaded with capacitive element in the embodiment four of the application;

[0041] Figure 13 is the radiation arm schematic diagram loaded with inductive element in the embodiment four of the application;

[0042] Figure 14 is the radiation arm schematic diagram with first stub in the embodiment four of the application;

[0043] Figure 15 is the radiation arm schematic diagram with second stub in the embodiment four of the application;

[0044] Figure 16 is the first kind of feed structure schematic diagram of the class four-arm spiral antenna in the embodiment five of the application;

[0045] Figure 17 is the second kind of feed structure schematic diagram of the class four-arm spiral antenna in the embodiment five of the application;

[0046] Figure 18 is the third kind of feed structure schematic diagram of the class four-arm spiral antenna in the embodiment five of the application;

[0047] Figure 19 is a fourth feeding structure diagram of the class four-arm helical antenna in the embodiment five of the application;

[0048] Figure 20 is a scattering parameter curve diagram of the class four-arm helical antenna in the embodiment one of the application;

[0049] Figure 21 is a scattering coefficient curve diagram when there are only two active radiation arms in the application;

[0050] Figure 22 is a transmission coefficient curve diagram with the change of the parasitic resonance (f1) in the application;

[0051] Figure 23 is an axial ratio curve diagram with the change of the parasitic resonance (f1) in the application;

[0052] Figure 24 is a circular polarization gain curve diagram with the change of the parasitic resonance (f1) in the application;

[0053] Figure 25 is a scattering coefficient curve diagram of a traditional four-arm helical antenna;

[0054] Figure 26 is a circular polarization gain curve diagram of a traditional four-arm helical antenna. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical scheme and advantages of the application more clear, the application is further described in detail below in combination with the drawings and embodiments.

[0056] The application relates to a miniaturized and light-weight circularly polarized antenna and a design method thereof, which is suitable for wireless communication and satellite navigation systems. A traditional four-arm helical antenna is difficult to balance between complexity, low cost and high performance. Therefore, the application provides a class four-arm helical antenna. The design is similar in function to the traditional four-arm helical antenna and can realize equivalent circularly polarized radiation characteristics, but by innovatively using two active radiation arms and two passive radiation arms, only a two-port can be used to complete differential signal feeding and circular polarization modulation. Compared with the traditional design, the application discards the complexity of the four-port power divider, optimizes the port isolation and energy distribution through the parasitic resonance of the passive radiation arm, significantly simplifies the design structure, reduces the manufacturing cost, and maintains high-performance circular polarization characteristics. This class four-arm helical antenna not only realizes miniaturization, but also provides higher design flexibility and environmental adaptability, and provides a compact and high-performance antenna solution for GNSS, satellite communication and 6G wireless communication fields.

[0057] Specifically, the four-arm-like helical antenna comprises a ground plate 100, active radiation arms and passive radiation arms, the active radiation arms and the passive radiation arms are connected to the ground plate 100, the active radiation arms are fed with differential signals to generate antenna resonance, the passive radiation arms are coupled from the active radiation arms fed with the differential signals to generate parasitic resonance, the two active radiation arms and the two passive radiation arms are arranged in a helical symmetric structure around a central area of the antenna, and the parasitic resonance frequency of the passive radiation arms deviates from the antenna resonance frequency of the active radiation arms.

[0058] The two active radiation arms adopt a combination of equal electrical lengths or a combination of unequal electrical lengths, the two passive radiation arms adopt a combination of equal electrical lengths or a combination of unequal electrical lengths, the electrical length of the active radiation arms is one of λ0 / 4 or an odd multiple of λ0 / 4, λ0 / 2 or an integer multiple of λ0 / 2, and the electrical length of the passive radiation arms is one of a deviation from λ0 / 4 or an odd multiple of λ0 / 4, a deviation from λ0 / 2 or an integer multiple of λ0 / 2, where λ0 is the wavelength of the working frequency of the antenna.

[0059] The following explains various structural modifications of the four-arm-like helical antenna through multiple embodiments.

[0060] Embodiment one:

[0061] The embodiment provides a design of a four-arm-like helical antenna, as shown in Figure 1 and Figure 2 The four-arm-like helical antenna comprises a ground plate 100, active radiation arms and passive radiation arms, the active radiation arms comprise a first active radiation arm 101a and a second active radiation arm 101b, the passive radiation arms comprise a first passive radiation arm 102a and a second passive radiation arm 102b, the ground ends of the first active radiation arm 101a, the second active radiation arm 101b, the first passive radiation arm 102a and the second passive radiation arm 102b are connected to the ground plate 100, the first active radiation arm 101a, the second active radiation arm 101b, the first passive radiation arm 102a and the second passive radiation arm 102b are arranged in a helical symmetric structure around a central area of the antenna and are spaced apart by 90 degrees in sequence, and the first active radiation arm 101a and the second active radiation arm 101b are introduced with differential signals with a phase difference of 90 degrees.

[0062] Figure 1The first active radiation arm 101a, the second active radiation arm 101b, the first passive radiation arm 102a, and the second passive radiation arm 102b are represented by lines of different thicknesses to more clearly distinguish their structures. The first active radiation arm 101a, the second active radiation arm 101b, the first passive radiation arm 102a, and the second passive radiation arm 102b are arranged in a rotationally symmetric structure around the antenna center region in sequence, forming a helical extension structure with a helical pitch, and collectively radiating electromagnetic waves along the z-axis direction, forming a compact and efficient radiation structure. Specifically, the second passive radiation arm 102b is obtained by rotating the first passive radiation arm 102a 90 degrees clockwise around the z-axis, and the second active radiation arm 101b is also generated by rotating the first active radiation arm 101a 90 degrees, thereby forming a rotationally symmetric structure of four radiation arms that are spatially adjacent and have an included angle of about 90 degrees. The ground plate 100 is arranged below the antenna and serves as a potential zero point to provide a stable ground reference for the antenna.

[0063] The class four-arm helical antenna also includes a feed branch, one end of the feed branch is connected with the active radiation arm, and the other end of the feed branch is connected with the feed port. The feed branch includes a first feed branch 103a and a second feed branch 103b, and the feed port includes a first feed port 104a and a second feed port 104b. One end of the first feed branch 103a is connected with the first active radiation arm 101a, and the other end of the first feed branch 103a is connected with the first feed port 104a, which is used to accurately control the input impedance matching of the first active radiation arm 101a; one end of the second feed branch 103b is connected with the second active radiation arm 101b, and the other end of the second feed branch 103b is connected with the second feed port 104b, which is responsible for optimizing and controlling the input impedance matching of the second active radiation arm 101b. In addition, the first active radiation arm 101a and the second active radiation arm 101b respectively introduce a differential signal with a phase difference of 90 degrees through the first feed port 104a and the second feed port 104b. Through the above input impedance matching and differential feeding method, the active radiation arm forms a stable antenna resonance at the operating frequency f0 and generates circularly polarized signal radiation.

[0064] To improve the port isolation and circular polarization performance, the first passive radiation arm 102a and the second passive radiation arm 102b are innovatively introduced. The two passive radiation arms generate a parasitic resonance (the frequency of the parasitic resonance is f1) near the operating frequency f0, balance the radiation energy through energy coupling and distribution, and ensure the symmetry and uniformity of the radiation pattern. At the same time, the parasitic resonance (f1) as a decoupling structure effectively improves the isolation between the first feed port 104a and the second feed port 104b, overcoming the problem of insufficient isolation caused by non-orthogonality in traditional designs.

[0065] In this embodiment, the first active radiation arm 101a, the second active radiation arm 101b, the first passive radiation arm 102a and the second passive radiation arm 102b are all single straight arm structures, one end of which is connected to the ground plate as the ground end, and the other end of which is spirally extended as the open end.

[0066] Figure 3 The current distribution of the four radiation arms in the four-arm-like helical antenna is shown to illustrate the working principle. As can be seen from the figure, Figure 3 It can be seen that the current intensity of the first active radiation arm 101a is the strongest at the ground end and the weakest at the open end, showing a typical standing wave distribution characteristic. This current distribution is consistent with the characteristics of a traditional monopole antenna or inverted F antenna. Therefore, the electrical length of the first active radiation arm 101a and the second active radiation arm 101b is designed to be λ0 / 4 or an odd multiple thereof, λ0 being the wavelength of the antenna operating frequency f0, so as to produce stable antenna resonance at the operating frequency f0 (the resonance frequency of the active radiation arm is the antenna operating frequency). Similarly, the current distribution of the first passive radiation arm 102a also shows a standing wave form with the strongest intensity at the ground end and the weakest intensity at the open end. However, the electrical length of the first passive radiation arm 102a and the second passive radiation arm 102b deviates slightly from λ0 / 4 or an odd multiple thereof, so as to produce a parasitic resonance (f1) near the antenna operating frequency f0, which provides key support for the performance optimization of the antenna.

[0067] Figure 4 The working principle of differential feeding is further shown. The four-arm-like helical antenna includes a radio frequency chip and a differential feeding network. The single-ended radio frequency signal output by the radio frequency chip is converted into two differential signals with equal amplitude and a phase difference of 90 degrees by the differential feeding network (such as a power divider or a balun circuit), and is fed in through the first feeding port 104a and the second feeding port 104b respectively. The feeding port is an abstract logical concept and is not a physical port, but represents the radio frequency signal from the radio frequency chip. The first feeding port 104a and the second feeding port 104b are connected to the first feeding branch 103a and the second feeding branch 103b respectively, so as to excite the first active radiation arm 101a and the second active radiation arm 101b. By this differential feeding method, the generation of circularly polarized signals can be effectively ensured. Moreover, the two active radiation arms simultaneously produce antenna resonance at the operating frequency f0 and realize signal radiation. However, since the first active radiation arm 101a and the second active radiation arm 101b are formed by a central rotational symmetry design, their distribution is not ideal orthogonal, which makes it difficult to generate completely orthogonal electric field components. In addition, this non-orthogonality also reduces the port isolation and affects the effective implementation of the differential signal. Therefore, it is difficult to form a stable circularly polarized signal only by relying on the first active radiation arm 101a and the second active radiation arm 101b.

[0068] To solve the above problems, the first passive radiation arm 102a and the second passive radiation arm 102b are innovatively introduced. Both of the two passive radiation arms are of a structure with one end grounded and the other end open, and the electrical length thereof slightly deviates from λ0 / 4 and its odd multiples, thereby generating a parasitic resonance (f1) near the antenna operating frequency f0. The parasitic resonance has a dual role: on the one hand, through energy transfer and uniform distribution among the four radiation arms, the radiation signal is balanced, ensuring the symmetry and uniformity of circularly polarized radiation; on the other hand, as a decoupling structure between the first active radiation arm 101a and the second active radiation arm 101b, the port isolation is effectively improved, ensuring the stable feeding of the differential signal. Thus, through the synergistic effect of the two active radiation arms (101a and 101b) and the two passive radiation arms (102a and 102b), the equivalent circularly polarized performance of the traditional four-arm spiral antenna is successfully realized.

[0069] In addition, the design parameters of the first passive radiation arm 102a and the second passive radiation arm 102b can be optimized by adjusting the height, width or morphology, etc., thereby realizing accurate regulation of the port isolation and the radiation pattern. This flexibility significantly improves the design freedom of the antenna, enabling it to maintain robustness in complex environments and diverse needs. In the best case, the structural parameters of the first passive radiation arm 102a and the second passive radiation arm 102b remain consistent, i.e., the second passive radiation arm 102b is obtained by rotating the first passive radiation arm 102a by 90 degrees from the center, to ensure symmetry and performance stability. Through the above technical solution, the embodiment simplifies the feed network while taking into account the characteristics of miniaturization, high isolation and efficient circularly polarized radiation, showing significant advantages over traditional designs.

[0070] Figure 5The equivalent circuit diagram of the class four-arm helix antenna in the application is shown to provide theoretical support for understanding the working mechanism. In the model, the first active radiation arm 101a and the second active radiation arm 101b are equivalent to a first series circuit (composed of resistance R1, inductance L1 and capacitance C1) and a second series circuit (composed of R2, L2 and C2) respectively, wherein the first feed port 104a and the second feed port 104b correspond to voltage sources V1 and V2 respectively. The first passive radiation arm 102a and the second passive radiation arm 102b are equivalent to a third series circuit (composed of R3, L3 and C3) and a fourth series circuit (composed of R4, L4 and C4) respectively. The overall equivalent circuit is composed of the first series circuit, the fourth series circuit, the third series circuit and the second series circuit coupled in sequence. The energy transmission and distribution between the circuits are realized through electromagnetic coupling, wherein k1 represents the coupling coefficient between the first circuit and the fourth circuit, k2 represents the coupling coefficient between the fourth circuit and the third circuit, k3 represents the coupling coefficient between the third circuit and the second circuit, and k4 represents the coupling coefficient between the first circuit and the second circuit. These coupling relationships ensure balanced radiation distribution on each circuit.

[0071] In particular, the fourth circuit and the third circuit are located between the first circuit and the second circuit, forming an additional coupling path. The coupling characteristics of the path are determined by k1, k2 and k3, and the amplitude and phase can be controlled by the resonant frequency of the fourth circuit and the third circuit (i.e. the parasitic resonance f1 of the first passive radiation arm 102a and the second passive radiation arm 102b). This additional coupling path can effectively cancel the direct electromagnetic coupling k4 between the first circuit and the second circuit (i.e. the coupling between the first active radiation arm 101a and the second active radiation arm 101b), thereby significantly improving the port isolation between the first feed port 104a and the second feed port 104b and ensuring stable transmission of differential signals.

[0072] According to the equivalent circuit model, assuming that the first circuit and the second circuit are the same, L1=L2=L, C1=C2=C, R1=R2=R; the third circuit and the fourth circuit are the same, L3=L4=L', C3=C4=C', R3=R4=R'. The input impedance of the first port and the second port can be expressed as follows:

[0073] ,

[0074] wherein, Figure 6 is the angular frequency, representing the working frequency of the antenna; jis the imaginary unit, representing the reactive power stored in the capacitance or inductance. R1, R2, R3 and R4 represent the radiation energy of each radiation arm, respectively, and the radiation energy R3 and R4 of the first passive radiation arm 102a and the second passive radiation arm 102b are determined by the coupling coefficients k1, k2 and k3. Therefore, the electromagnetic coupling strength between the radiation arms becomes a key parameter for optimizing the performance of the antenna.

[0075] Based on the above theory, the following design optimization scheme is proposed in this embodiment:

[0076] (1) Optimize electromagnetic coupling: To ensure the uniformity and symmetry of the radiation pattern, the energy distribution on each radiation arm needs to be regulated. The energy distribution is determined by the electromagnetic coupling strength between the radiation arms, and the electromagnetic coupling strength is determined by the frequency difference |f0-f1| and the spatial distance between the active radiation arms (101a and 101b) and the passive radiation arms (102a and 102b). Generally, to maintain effective electromagnetic coupling strength, the minimum distance between the radiation arms should be less than 0.05λ0 (λ0 is the wavelength corresponding to f0), which makes the application particularly suitable for compact design scenarios. In the strong coupling scenario, the frequency difference should be appropriately increased to reduce the excessive energy interference; in the weak coupling scenario, the frequency difference needs to be reduced to improve the coupling efficiency. To achieve the best performance, the frequency difference between f0 and f1 is controlled within ±20% of f0.

[0077] (2) Optimize port isolation: To ensure the accurate feeding of differential signals, the port isolation between the first feeding port 104a and the second feeding port 104b is crucial. Since the non-orthogonality of the first active radiation arm 101a and the second active radiation arm 101b will cause the isolation to decrease, affecting the stability of the signal phase and amplitude, this design introduces the first passive radiation arm 102a and the second passive radiation arm 102b as a decoupling structure, effectively improving the port isolation.

[0078] By coupling constraints between passive radiation arms and active radiation arms, the application optimizes the coupling strength between the radiation arms and the port isolation between the active radiation arms, achieving circular polarization performance that is not inferior or superior to that of traditional four-arm spiral antennas. Compared with traditional designs, the antenna of the application significantly reduces the physical size while maintaining high radiation efficiency, and enhances the design adaptability through flexible parameter adjustment. This feature makes it particularly suitable for multi-frequency GNSS, satellite communication and 6G wireless communication and other application scenarios that require high-precision radiation.

[0079] Embodiment two:

[0080] As Figure 7As shown, the four-arm spiral antenna includes a ground plate 100, active radiation arms including a third active radiation arm 201a and a fourth active radiation arm 201b, and passive radiation arms including a third passive radiation arm 202a and a fourth passive radiation arm 202b. The four radiation arms are sequentially arranged in a central symmetric manner to form a high-efficiency radiation structure. The ground plate 100 is arranged below the antenna and serves as a potential zero point to provide a stable ground reference for the antenna.

[0081] In the design, the third active radiation arm 201a and the fourth active radiation arm 201b are fed with differential signals through a third feed port 204a and a fourth feed port 204b, respectively, and the phase difference between the signals is 90 degrees, thereby generating antenna resonance at an operating frequency f0 of the antenna. The third active radiation arm 201a is grounded at both ends, and the electrical length thereof is designed as λ0 / 2 (λ0 is the wavelength of the operating frequency f0 of the antenna) or an integer multiple thereof to form stable resonance at f0. A third feed branch 203a is connected at one end to the third feed port 204a and at the other end to the third active radiation arm 201a, and is used to accurately control the input impedance thereof. Similarly, the fourth active radiation arm 201b is also a structure grounded at both ends, and the electrical length thereof is λ0 / 2 or an integer multiple thereof to generate resonance at f0. A fourth feed branch 203b is connected at one end to the fourth feed port 204b and at the other end to the fourth active radiation arm 201b, and is responsible for optimizing the input impedance matching thereof. Compared with the first embodiment, the double-end grounding design of the radiation arm further improves the structural stability.

[0082] Figure 8 to Figure 10 The current distribution schematic of the four-arm spiral antenna in the application is shown to illustrate the working principle of each radiation arm. As can be seen from the figure, the current intensity of the third active radiation arm 201a is the strongest at the grounding ends and the weakest at the middle node position of the radiation arm, showing a typical standing wave distribution characteristic. The current distribution conforms to the characteristics of a conventional loop antenna. Therefore, the electrical length of the third active radiation arm 201a and the fourth active radiation arm 201b is λ0 / 2 or an integer multiple thereof, ensuring that the antenna resonance occurs at the operating frequency f0 of the antenna. Similarly, the current intensity of the third passive radiation arm 202a is the strongest at the grounding ends and the weakest at the middle node position, also showing a standing wave characteristic. However, the electrical length of the third passive radiation arm 202a and the fourth passive radiation arm 202b is slightly higher or lower than λ0 / 2 or an integer multiple thereof, thereby generating a parasitic resonance (f1) near the operating frequency f0 of the antenna.

[0083] The third feeding port 204a and the fourth feeding port 204b are connected with the radio frequency chip through a differential feeding network such as a power divider, a balun circuit, etc., and are used for feeding in a differential radio frequency signal with a phase difference of 90 degrees. However, it is difficult to realize an ideal circularly polarized signal by only relying on the third active radiation arm 201a and the fourth active radiation arm 201b, because the central symmetry design may cause non-orthogonality, thereby affecting the orthogonality of the electric field components and the port isolation. Therefore, the third passive radiation arm 202a and the fourth passive radiation arm 202b are innovatively introduced in the embodiment. Both of the passive radiation arms are two-terminal grounded structures, and by generating a parasitic resonance (f1) near the working frequency f0, the following functions are realized: on the one hand, by energy transmission and uniform distribution among the four radiation arms, the radiation signal is balanced to ensure the symmetry and uniformity of the circularly polarized radiation; on the other hand, as a decoupling structure between the third active radiation arm 201a and the fourth active radiation arm 201b, the parasitic resonance effect is used to improve the port isolation and ensure the effective feeding of the differential signal.

[0084] By adopting the cooperative design of two active radiation arms (201a and 201b) and two passive radiation arms (202a and 202b), the equivalent circularly polarized performance of the traditional four-arm spiral antenna is successfully realized in the embodiment. In addition, by adjusting the parameters (such as height, width or shape) of the third passive radiation arm 202a and the fourth passive radiation arm 202b, the port isolation, beam pointing, radiation pattern characteristics, etc. can be further optimized, thereby improving the design freedom and environmental adaptability of the antenna. This design simplifies the feeding network, significantly reduces the manufacturing complexity, and balances miniaturization and high performance, and is particularly suitable for high-precision application scenarios such as GNSS, satellite communication and 6G wireless communication.

[0085] Embodiment three:

[0086] As shown in Figure 11 to Figure 15 The low-profile four-arm spiral antenna includes a ground plate 100, a fifth active radiation arm 301a, a sixth active radiation arm 301b, a fifth passive radiation arm 302a and a sixth passive radiation arm 302b. The four radiation arms are arranged in a central symmetry manner in sequence to form a compact and efficient radiation structure. The ground plate 100 is located below the antenna and serves as a potential zero point to provide a stable ground reference for the antenna.

[0087] The fifth active radiation arm 301a, the sixth active radiation arm 301b, the fifth passive radiation arm 302a, and the sixth passive radiation arm 302b are designed on the basis of the first active radiation arm 101a, the second active radiation arm 101b, the first passive radiation arm 102a, and the second passive radiation arm 102b, or on the basis of the third active radiation arm 201a, the fourth active radiation arm 201b, the third passive radiation arm 202a, and the fourth passive radiation arm 202b, and are designed to include a vertical radiation branch and a horizontal radiation branch, one end of the vertical radiation branch is connected to the ground plate 100, the other end of the vertical radiation branch is connected to one end of the horizontal radiation branch, and the other end of the horizontal radiation branch extends in a spiral shape in the horizontal plane to form a low-profile inverted L-shaped antenna structure.

[0088] Unlike the first embodiment and the second embodiment, the four radiation arms in the third embodiment are all designed in a low-profile manner, and the height is significantly reduced (generally only 0.03λ0), which is particularly suitable for compact devices with limited space. The fifth active radiation arm 301a and the sixth active radiation arm 301b are both designed in a structure with one end grounded and the other end open, and the electrical length is designed to be λ0 / 4 (λ0 is the wavelength of the operating frequency f0) or an odd multiple thereof, so as to generate stable antenna resonance at the operating frequency f0 of the antenna. The fifth active radiation arm 301a is fed with a differential signal through the fifth feeding port 304a, and the input impedance is adjusted by the fifth feeding branch 303a; the sixth active radiation arm 301b is fed with a differential signal through the sixth feeding port 304b, and the input impedance is optimized by the sixth feeding branch 303b. The fifth feeding port 304a and the sixth feeding port 304b provide a differential signal with a phase difference of 90 degrees to excite circularly polarized radiation.

[0089] The fifth passive radiation arm 302a and the sixth passive radiation arm 302b are also designed in a low-profile structure with one end grounded and the other end open, and the electrical length is slightly higher or lower than λ0 / 4 and its odd multiples, so as to generate a parasitic resonance (the frequency of the parasitic resonance is f1) near the operating frequency f0 of the antenna. The parasitic resonance plays a key role in achieving circular polarization performance and improving port isolation: on the one hand, through energy coupling with the active radiation arms, the symmetry and uniformity of the radiation signal are balanced; on the other hand, as a decoupling structure between the fifth active radiation arm 301a and the sixth active radiation arm 301b, the isolation between the fifth feeding port 304a and the sixth feeding port 304b is enhanced, and the effective transmission of the differential signal is ensured.

[0090] Embodiment four:

[0091] Figure 11The various optional design schemes of the radiation arm in the embodiment one of the application are shown, and the applicability of the antenna is further expanded and the performance is improved through structural optimization. According to the specific application requirements, the form and configuration of the radiation arm can be flexibly adjusted to meet the requirements of impedance matching, frequency tuning and miniaturization, etc.

[0092] As shown in Figure 2 , and in combination with Figure 12 , the design significantly improves the compactness of the antenna by configuring the radiation arm as a U shape, making it easier to integrate into space-limited devices while maintaining good radiation performance. In addition, the current path is also extended by designing a serpentine path to increase the adjustable range of the resonant mode, especially optimizing the resonant performance in the low frequency band, suitable for application scenarios that require wideband or low frequency adaptation.

[0093] As shown in Figure 2 , and in combination with Figure 13 , the four-arm-like spiral antenna also includes a first capacitive element 41, one end of which is connected to the open end of the radiation arm, and the other end is electrically connected to the ground plate 100. The open end of the first active radiation arm 101a, the second active radiation arm 101b, the first passive radiation arm 102a, and the second passive radiation arm 102b is loaded with the first capacitive element 41, which is electrically connected to the ground plate 100. Through the capacitive effect, the resonant frequency is adjusted and the input impedance matching is optimized, and the performance stability of the antenna at the working frequency f0 is improved.

[0094] As shown in Figure 14 , the four-arm-like spiral antenna also includes a first inductive element 42, one end of which is connected to the ground end of the first active radiation arm 101a, the second active radiation arm 101b, the first passive radiation arm 102a, and the second passive radiation arm 102b, and the other end is electrically connected to the ground plate. The ground end of the first active radiation arm 101a, the second active radiation arm 101b, the first passive radiation arm 102a, and the second passive radiation arm 102b is loaded with the first inductive element 42, which effectively reduces the resonant frequency and enhances the low frequency radiation efficiency through the inductive effect. These loading schemes further improve the resonant characteristics, support miniaturization design, and are suitable for space and cost sensitive applications.

[0095] As shown in Figure 2 , and in combination with Figure 15The quasi-four-arm helical antenna further comprises current branches for forming additional current paths, one or more of the active radiation arms and the passive radiation arms are connected with the current branches. The current branches comprise a first branch 43a, a second branch 43b, a third branch 44a, and a fourth branch 44b. The first branch 43a is connected to the first active radiation arm 101a, the second branch 43b is connected to the second active radiation arm 101b, the third branch 44a is connected to the first passive radiation arm 102a, and the fourth branch 44b is connected to the second passive radiation arm 102b. One or more of the four arms, i.e., the first active radiation arm 101a, the second active radiation arm 101b, the first passive radiation arm 102a, and the second passive radiation arm 102b, can select the setting mode of the current branches.

[0096] The first branch 43a and the second branch 43b are respectively connected to the first active radiation arm 101a and the second active radiation arm 101b, and form additional current paths through direct connection, generate antenna resonance of the second operating frequency f2, and realize dual-frequency or wide-frequency function. Alternatively, the third branch 44a and the fourth branch 44b are respectively connected to the first passive radiation arm 102a and the second passive radiation arm 102b, generate additional current paths, generate parasitic resonance f3 close to the second operating frequency f2, and further optimize the port isolation and energy distribution of the second operating frequency f2 band. Through the synergistic effect of the active and passive radiation arms, the quasi-four-arm helical antenna with dual-frequency characteristics is constructed.

[0097] As shown in FIG. 4, and in combination with FIGS. 3 and 5, Figure 2 Figure 13 and Figure 11 to Figure 15 The quasi-four-arm helical antenna further comprises electromagnetic coupling branches for forming spatial electromagnetic coupling, one or more of the active radiation arms and the passive radiation arms are provided with the electromagnetic coupling branches, and the electromagnetic coupling branches are arranged on one side of the active radiation arms and / or the passive radiation arms.

[0098] The electromagnetic coupling branches comprise a fifth branch 45a, a sixth branch 45b, a seventh branch 46a, and an eighth branch 46b. The fifth branch 45a is arranged on one side of the first active radiation arm 101a and forms spatial electromagnetic coupling, the sixth branch 45b is arranged on one side of the second active radiation arm 101b and forms spatial electromagnetic coupling, the seventh branch 46a is arranged on one side of the first passive radiation arm 102a and forms spatial coupling, and the eighth branch 46b is arranged on one side of the second passive radiation arm 102b and forms spatial coupling. One or more of the four arms, i.e., the first active radiation arm 101a, the second active radiation arm 101b, the first passive radiation arm 102a, and the second passive radiation arm 102b, can select the setting mode of the electromagnetic coupling branches.

[0099] ​The fifth branch 45a and the sixth branch 45b are not directly connected to the first active radiation arm 101a and the second active radiation arm 101b, but generate an antenna resonance at f2 through spatial electromagnetic coupling at the first feed port 104a and the second feed port 104b. The fifth branch 45a and the sixth branch 45b can be designed as a one-end grounded or two-end grounded structure, and the electrical length thereof is λ2 / 4 (λ2 is the wavelength of the second operating frequency f2) or an integer multiple thereof, to generate a resonance at f2. Alternatively, the seventh branch 46a and the eighth branch 46b act on the first passive radiation arm 102a and the second passive radiation arm 102b through spatial coupling to generate a parasitic resonance f3 close to f2, to further improve the port decoupling and energy uniformity of the f2 frequency band. This non-contact coupling mode enhances the frequency coverage range and realizes a dual-frequency or wide-frequency characteristic.

[0100] The four-arm-like spiral antenna in the present application can also adopt a multi-group radiation arm configuration and be distributed in a rotational symmetry manner to realize higher-level functions. For example, the first group of radiation arms includes two active radiation arms and two passive radiation arms, wherein the two active radiation arms operate at a first operating frequency f0, and the two passive radiation arms generate a parasitic resonance (f1) near f0, for optimizing the circular polarization and port isolation of the first frequency band. The second group of radiation arms also includes two active radiation arms and two passive radiation arms, wherein the two active radiation arms operate at a second operating frequency f2, and the two passive radiation arms generate a parasitic resonance f3 near f2, for optimizing the circular polarization and port isolation of the second frequency band. By adjusting the arrangement combination and direction of the two groups of radiation arms, it is ensured that the operating frequencies do not interfere with each other, thereby realizing a dual-frequency characteristic. This co-aperture antenna design significantly improves the system integration and is suitable for multi-frequency band application scenarios.

[0101] The capacitive element has a capacitive characteristic and can be a lumped element or a distributed element. For example, the lumped element includes a chip capacitor, a variable capacitor, an electrolytic capacitor, a ceramic capacitor, a thin-film capacitor, etc., and the distributed capacitive element can include parallel wires (two or more wires arranged in parallel, and the capacitance value is adjusted by adjusting the wire spacing and length), a transmission line structure (such as a microstrip line or a coaxial cable), a capacitive plate (two parallel metal plates are separated by a dielectric layer or an air gap), and a PCB planar capacitor structure (a metal pattern of a finger or interlaced structure is printed on a PCB board to optimize the capacitive characteristic).

[0102] These capacitive elements can be used alone or in combination. For example, a specific equivalent capacitance is obtained through series or parallel combination of multiple capacitive elements. In addition, the capacitive element can also be replaced by a combination structure of a capacitive element and an inductive element to optimize the resonance performance of the antenna. Similarly, the inductive element can also be a lumped element (such as a chip inductor, a chip resistor) or a distributed element (such as a wire, a coil, etc.). Similarly, multiple inductive elements can be combined to improve the overall performance of the antenna.

[0103] Figure 16 The structural change configuration is also applicable to the radiation arm structures of the third active radiation arm, the fourth active radiation arm, the third passive radiation arm and the fourth passive radiation arm in Embodiment Two.

[0104] Through the above optimization scheme, the present application significantly enhances the resonance regulation capability and polarization stability of the antenna while maintaining the miniaturized design. The diversified design of the radiation arm form and the implementation of the dual-frequency configuration enable the four-arm spiral antenna to flexibly adapt to the requirements of various wireless communication systems such as GNSS, unmanned aerial vehicle communication, 6G wireless communication and vehicle positioning, and exhibits excellent environmental adaptability and performance advantages.

[0105] Embodiment Five:

[0106] As shown in Figure 2 and in combination with Figure 17 , the four-arm-like spiral antenna further includes a feed branch, which is arranged on one side of the active radiation arm, one end of the feed branch forms a coupling gap with the active radiation arm, and the other end of the feed branch is connected to a feed port. The feed branch includes a first feed branch 103a and a second feed branch 103b, and the feed port includes a first feed port 104a and a second feed port 104b. One end of the first feed branch 103a is connected to the first feed port 104a, and the other end is in an open circuit state, forming a kind of coupled feed structure; one end of the second feed branch 103b is connected to the second feed port 104b, and the other end is in an open circuit state, forming a kind of coupled feed structure. This design adjusts the resonant frequency of the first feed branch 103a and the coupling strength between the first feed branch 103a and the first active radiation arm 101a to realize accurate regulation of the input impedance of the first active radiation arm 101a. This method is conducive to realizing wide frequency characteristics and improving the bandwidth adaptability of the antenna.

[0107] As shown in Figure 2 and in combination with Figure 18 , the four-arm-like spiral antenna further includes a first element 51, one end of the first feed branch 103a is electrically connected to the first active radiation arm 101a in series through the first element 51, and one end of the second feed branch 103b is electrically connected to the second active radiation arm 101b in series through the first element 51. The first element 51 can be a capacitive element, an inductive element or a combination thereof. By adjusting the capacitance value or inductance value of the first element 51, effective matching regulation of the input impedance of the antenna can be realized. The specific selection depends on the optimization target to further enhance the flexibility and adjustability of the input impedance matching.

[0108] As shown in Figure 2 and in combination with Figure 16 to Figure 18The class four-arm spiral antenna further comprises a second element 52 connected in parallel to one side of the first feeding branch 103a and the second feeding branch 103b, and the second element 52 can be a capacitive element, an inductive element or a combination thereof. The second element 52 is connected in parallel to one side of the first feeding branch 103a and the second feeding branch 103b, forming a parallel feeding loop. By introducing the parallel element, the input impedance matching characteristics of the first active radiation arm 101a and the second active radiation arm 101b are further regulated, effectively expanding the bandwidth or optimizing the performance of a specific frequency band.

[0109] The above Figure 19 feeding schemes are applicable to the third active radiation arm 201a and the fourth active radiation arm 201b. In the optimal design, the structural parameters and feeding methods of the first active radiation arm 101a and the second active radiation arm 101b are consistent, that is, the second active radiation arm 101b is obtained by rotating the first active radiation arm 101a by 90 degrees at the center, to ensure the symmetry of the differential signal and the stability of the circularly polarized radiation.

[0110] As Figure 19 shown, the class four-arm spiral antenna further comprises a matching network, a differential feeding network and a radio frequency chip, the differential feeding network is connected to the active radiation arm through the matching network, and the radio frequency chip is connected to the differential feeding network. The matching network and the feeding branch are two schemes for adjusting the input impedance matching of the antenna, Figure 4 In the matching network, the matching network is used to replace the feeding branch structure in the Figure 16 to Figure 19 The matching network comprises a first matching network and a second matching network.

[0111] The signals output by the radio frequency chip are converted into differential signals with a phase difference of 90 degrees by the differential feeding network, and are fed into the first active radiation arm 101a and the second active radiation arm 101b respectively. At this time, it is equivalent to that the first feeding port 104a and the second feeding port 104b are directly connected to the first active radiation arm 101a and the second active radiation arm 101b respectively, without passing through the feeding branch. In order to achieve good input impedance matching, the two feeding signals pass through the first matching network and the second matching network respectively and are connected to the corresponding radiation arm. The above matching network can adopt common PI type, L type or other forms, which is used to adjust the input impedance, improve the matching efficiency and ensure the effective transmission of the radio frequency signal and the stable performance of the antenna. It should be pointed out that the input impedance matching in the present application can not only be realized by the above Figure 20 to Figure 26The shown feed branch structure implementation can also combine various feed and tuning methods commonly used for PIFA antennas. For example, the electrical length and standing wave characteristics of the antenna can be adjusted by adjusting the feed port position (such as moving along the length of the radiating arm), optimizing the ground position, introducing a shorting pin or shorting plate, thereby achieving fine tuning and optimization of the input impedance; in addition, tuning elements such as series or parallel inductors, capacitors, varactor diodes, etc. can also be introduced in the feed path to achieve fine matching control and wideband characteristic adjustment.

[0112] In specific implementations, these control methods can be used alone or in combination with differential feed structure to meet the comprehensive performance requirements of antenna miniaturization, high isolation, wideband or dual-frequency operation in different scenarios. Through the diversified design of the above feed and matching methods, the present application not only improves the design flexibility and matching ability of the four-arm spiral antenna, but also enhances its ability to adapt to GNSS, satellite communication, unmanned aerial vehicle link and 6G multi-scenario, multi-standard wireless communication systems, and has good engineering practicability and popularization value.

[0113] Figure 20 The simulation data in Embodiment 1 of the present application is shown, and the performance advantages and key features of the design are verified through parameters such as scattering coefficient, transmission coefficient, axial ratio and circular polarization gain.

[0114] Figure 21 The scattering coefficient curve of the present embodiment is shown, in which the reflection coefficient curve 601 reflects the antenna resonance (f0) generated by the first feed port 104a and the second feed port 104b at the operating frequency (such as the L1 frequency band), showing excellent input impedance matching characteristics. The resonance is generated by the first active radiating arm 101a and the second active radiating arm 101b. At the same time, the parasitic resonance (f1) generated by the first passive radiating arm 102a and the second passive radiating arm 102b is clearly visible in the curve, and its frequency is lower than the antenna resonance (f0), which is different from the traditional four-arm spiral antenna and embodies the innovation of the present application. The transmission coefficient curve 602 represents the energy transfer between the first feed port 104a and the second feed port 104b, reflecting the port coupling strength. At the antenna resonance (f0) frequency band, the port isolation is as high as 20 dB, indicating excellent decoupling performance. In contrast, Figure 22 to Figure 24 The case where only the first active radiating arm 101a and the second active radiating arm 101b (without the first passive radiating arm 102a and the second passive radiating arm 102b) are included is shown, and the reflection coefficient curve 605 shows that the antenna resonance (f0) is basically not affected, but the parasitic resonance (f1) disappears. At this time, the port isolation is only about 3 dB, which severely limits the effective feeding of the orthogonal differential signal.

[0115] Figure 22This further demonstrates the impact of parasitic resonance (f1) variation on antenna performance. Figure 23 The graph shows the variation of the transmission coefficient. Figure 24 This is a graph showing the change in axial ratio. Figure 22 This is a graph showing the change in circular polarization gain. (From...) Figure 23 It can be seen that as the frequency of the parasitic resonance (f1) decreases, the port isolation at the antenna resonance (f0) gradually deteriorates. Specifically, the higher isolation (approximately 20 dB) corresponding to curve 602a ensures... Figure 24 The excellent axial ratio curve 603a (close to the ideal value) and Figure 25 The circular polarization gain curve 604a shows a relatively high gain. When f1 decreases to the state corresponding to curve 602b, the isolation deteriorates, the axial ratio curve 603b worsens to over 4 dB, and the gain curve 604b decreases by approximately 2 dB (compared to 604a). When f1 further decreases to the state corresponding to curve 602c, the isolation continues to decline, the axial ratio curve 603c worsens to over 8 dB, and the gain curve 604c decreases by approximately 4 dB (compared to 604a). These data indicate that the frequency position of the parasitic resonance (f1) is crucial to isolation, axial ratio, and gain.

[0116] Figure 26 and Figure 25 Simulation results of a traditional four-arm helical antenna are shown for comparison. Figure 26 The reflection coefficient curve 607 shows that the conventional design also achieves excellent input impedance matching at the operating frequency; however, the transmission coefficient curve 608 shows that its port isolation is only about 7 dB. Nevertheless, ​ The circular polarization gain curve 609 still exhibits high gain. This is due to the fact that the traditional quad-arm helical antenna uses four ports to feed differential signals, and the orthogonal electric field components and circular polarization characteristics are forced through a complex power divider network, but this also significantly increases the design complexity and manufacturing cost.

[0117] The simulation results above demonstrate that the present invention introduces parasitic resonance (f1) through the first passive radiating arm 102a and the second passive radiating arm 102b, effectively decoupling the first feed port 104a and the second feed port 104b, thereby ensuring stable differential signal feeding. Simultaneously, the electromagnetic coupling between the active and passive radiating arms optimizes the symmetry and uniformity of radiation, enabling the antenna to achieve wide axial ratio and high gain circular polarization performance using only two feed ports. Compared to traditional four-arm helical antennas, this design not only reduces complexity and cost but also maintains excellent radiation characteristics in a miniaturized structure, making it suitable for demanding scenarios such as GNSS and satellite communications.

[0118] In some other optional embodiments, the application also provides an electronic device comprising the four-arm-like helical antenna structure as described in the above optional embodiments. For example, the electronic device is a communication module, a vehicle-mounted station, or a drone, etc.

[0119] The four-arm-like helical antenna of the application has the following three technical advantages in terms of structure, performance, and application adaptability:

[0120] (1) Simplification and miniaturization design: Compared with the traditional four-arm helical antenna which needs to rely on four feeding ports and a complex power division network, the application innovatively uses only two feeding ports to realize differential signal feeding. This design significantly reduces the number of devices, complexity, and manufacturing cost of the differential circuit, while achieving equivalent circular polarization performance as the traditional four-arm helical antenna in a compact structure, providing an efficient solution for miniaturized device integration.

[0121] (2) High performance and adjustability: The application introduces two passive radiation arms, which significantly improve the performance and design flexibility of the antenna. On the one hand, the passive radiation arms optimize the port isolation between the two active radiation arms through parasitic resonance (f1), ensuring ideal input of differential signals and thus excellent circular polarization axial ratio and high gain characteristics. On the other hand, the electromagnetic coupling between the four radiation arms achieves uniform distribution of radiation energy, further enhancing the symmetry of the radiation pattern. In addition, by adjusting the parameters (such as electrical length, height, shape, etc.) of the passive radiation arms, the resonant frequency and performance characteristics can be flexibly controlled, enabling the antenna to adapt to diverse and complex application scenarios.

[0122] (3) Enhanced application adaptability: Thanks to the simplified design and high adjustability, the application significantly improves the environmental adaptability and system integration of the antenna while maintaining high performance. Whether it is single-frequency optimization or dual-frequency co-aperture design, the antenna can meet the needs of GNSS, drone communication, 6G wireless communication, vehicle positioning, and other wireless communication systems through structural optimization, demonstrating excellent robustness and practicality.

[0123] In summary, the four-arm-like helical antenna of the application, through innovative structural design and performance optimization, not only overcomes the complexity and size limitations of traditional designs, but also achieves significant breakthroughs in performance and application flexibility, providing important support for the development of modern wireless communication technology.

[0124] The structure of the antenna can be adjusted accordingly according to specific design needs. The specific shape, structure, wiring form, and feeding method of the radiation arm and ground plate can be different to meet the requirements of input impedance matching, operating frequency, structural optimization, etc. The shape of the antenna in each embodiment of the application is only illustrative and is not limited to the shapes listed in the drawings of the application specification.

[0125] The above description is further detailed in connection with specific preferred embodiments of the application, and it is not to be construed that the specific implementation of the application is limited to these descriptions. For those skilled in the art of the present application, without departing from the concept of the present application, a number of simple deductions or substitutions can be made, and all of them should be considered as falling within the protection scope of the present application.

Claims

1. A quasi-quadrifilar helix antenna characterized by, The antenna comprises a ground plate, active radiation arms and passive radiation arms, the active radiation arms and passive radiation arms are connected to the ground plate respectively, two active radiation arms are fed with signals with a phase difference of 90 degrees to generate antenna resonance, two passive radiation arms are coupled from the two active radiation arms to generate parasitic resonance, the two active radiation arms and the two passive radiation arms are arranged in a spiral symmetric structure around the center area of the antenna in sequence, the passive radiation arms generate parasitic resonance frequency f1 near the working frequency f0 of the active radiation arms, and the two active radiation arms and the two passive radiation arms jointly generate circularly polarized signal radiation at the antenna resonance frequency f0.

2. The quasi-quadrifilar helical antenna of claim 1, wherein, The two active radiation arms adopt a combination of equal electrical lengths or a combination of unequal electrical lengths, the two passive radiation arms adopt a combination of equal electrical lengths or a combination of unequal electrical lengths, the electrical length of the active radiation arms is one of λ0 / 4 or an odd multiple of λ0 / 4, λ0 / 2 or an integer multiple of λ0 / 2, and the electrical length of the passive radiation arms is one of deviating from λ0 / 4 or an odd multiple of λ0 / 4, deviating from λ0 / 2 or an integer multiple of λ0 / 2, wherein λ0 is the wavelength of the working frequency of the antenna.

3. The quasi-four-arm spiral antenna according to claim 1, wherein The active radiation arms comprise a first active radiation arm and a second active radiation arm, the passive radiation arms comprise a first passive radiation arm and a second passive radiation arm, one end of the first active radiation arm, the second active radiation arm, the first passive radiation arm and the second passive radiation arm is connected to the ground plate respectively, and the first active radiation arm, the second active radiation arm, the first passive radiation arm and the second passive radiation arm are arranged in a spiral symmetric structure around the center area of the antenna in sequence, the electrical length of the first active radiation arm and the second active radiation arm is λ0 / 4 or an odd multiple of λ0 / 4, and the electrical length of the first passive radiation arm and the second passive radiation arm deviates from λ0 / 4 or an odd multiple of λ0 / 4. Or the active radiation arms comprise a third active radiation arm and a fourth active radiation arm, the passive radiation arms comprise a third passive radiation arm and a fourth passive radiation arm, two ends of the third active radiation arm, the fourth active radiation arm, the third passive radiation arm and the fourth passive radiation arm are connected to the ground plate respectively, the third active radiation arm, the fourth active radiation arm, the third passive radiation arm and the fourth passive radiation arm are arranged in a spiral symmetric structure around the center area of the antenna in sequence, the electrical length of the third active radiation arm and the fourth active radiation arm is λ0 / 2 or an integer multiple of λ0 / 2, and the electrical length of the third passive radiation arm and the fourth passive radiation arm deviates from λ0 / 2 or an integer multiple of λ0 / 2.

4. The quasi-quadrifilar helical antenna of claim 3, wherein, A first capacitive element is further included, and the open ends of the first active radiation arm, the second active radiation arm, the first passive radiation arm and the second passive radiation arm are electrically connected to the ground plate through the first capacitive element respectively.

5. The quasi-quadrifilar helical antenna of claim 3, wherein, A first inductive element is further included, and the ground ends of one or more of the first active radiation arm, the second active radiation arm, the first passive radiation arm and the second passive radiation arm are electrically connected to the ground plate through the first inductive element. One or both ends of the third active radiation arm, the fourth active radiation arm, the third passive radiation arm, the fourth passive radiation arm are electrically connected to the ground plate through the first inductive element.

6. The quasi-quadrifilar helical antenna of claim 1, wherein, The active radiation arm and the passive radiation arm are each provided with a vertical radiation branch and a horizontal radiation branch, the vertical radiation branch is connected to the ground plate, and the horizontal radiation branch is connected to the vertical radiation branch and extends spirally in the horizontal plane to form a low-profile antenna structure.

7. The quasi-quadrifilar helical antenna of claim 1, wherein, A current branch for forming an additional current path is further included, and one or more of the active radiation arm and the passive radiation arm are connected with the current branch.

8. The quasi-quadrifilar helical antenna of claim 1, wherein, An electromagnetic coupling branch for forming a spatial electromagnetic coupling is further included, and one or more of the active radiation arm and the passive radiation arm are provided with the electromagnetic coupling branch, and the electromagnetic coupling branch is arranged on one side of the active radiation arm and / or the passive radiation arm.

9. The quasi-quadrifilar helical antenna of claim 1, wherein, A feeding branch is further included, and the feeding branch is arranged on one side of the active radiation arm, one end of the feeding branch forms a coupling gap with the active radiation arm, and the other end of the feeding branch is connected to a feeding port.

10. The quasi-quadrifilar helical antenna of claim 1, wherein, A feeding branch is further included, and one end of the feeding branch is connected to the active radiation arm, and the other end of the feeding branch is connected to a feeding port.

11. The quasi-quadrifilar helical antenna of claim 10, wherein, A first element is further included, and one end of the feeding branch is connected in series to the active radiation arm through the first element, and the first element is a capacitive element, an inductive element, or a combination of the two.

12. The quasi-quadrifilar helical antenna of claim 10, wherein, A second element is further included, and the second element is connected in parallel on one side of the feeding branch, and the second element is a capacitive element, an inductive element, or a combination of the two.

13. The quasi-quadrifilar helical antenna of any one of claims 9 to 12, wherein, A differential feeding network and a radio frequency chip are further included, the differential feeding network is connected to the feeding port, and the radio frequency chip is connected to the differential feeding network.

14. The quasi-quadrifilar helical antenna of claim 1, wherein, A matching network, a differential feeding network, and a radio frequency chip are further included, the differential feeding network is connected to the active radiation arm through the matching network, and the radio frequency chip is connected to the differential feeding network.

15. The quasi-quadrifilar helical antenna of claim 1, wherein, The active radiation arm fed with a differential signal generates an antenna resonance operating frequency f0, the passive radiation arm generates a parasitic resonance operating frequency f1, and the frequency difference between f0 and f1 is controlled within ±20% of f0.

16. The quasi-quadrifilar helical antenna of claim 1, wherein, The minimum spacing between each radiation arm is less than 0.05λ0, and λ0 is the wavelength of the operating frequency of the antenna.

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