Satellite TT&C antenna

Abstract

The application provides a satellite TT&C antenna, which comprises a radiation patch layer, a first dielectric plate, a ground layer, a second dielectric plate and a feed network layer, the radiation patch layer is attached to the upper surface of the first dielectric plate, the ground layer is arranged between the lower surface of the first dielectric plate and the upper surface of the second dielectric plate, and the feed network layer is attached to the lower surface of the second dielectric plate; wherein the radiation patch layer is composed of a plurality of annular array spiral patch units which are not connected to each other, the plurality of spiral patch units are connected to the feed network layer through metal through-hole columns respectively, and the metal through-hole columns penetrate through the first dielectric plate, the ground layer and the second dielectric plate. The antenna places a plurality of spiral segment dipole patches on the dielectric plate, and then feeds through a feed network, thereby ensuring the impedance matching bandwidth, significantly improving the ARBW width, and realizing efficient dual-polarized beam radiation, so as to meet the urgent needs of modern aerospace tasks for high-performance and high-reliability TT&C terminals.

Description

Technical Field

[0001] This invention relates to the technical field of antenna communication, and in particular to a satellite telemetry and control antenna. Background Technology

[0002] The X-band, a commonly used frequency band for satellite telemetry, tracking, and command (TT&C), is favored due to its high frequency, wide bandwidth, and low ionospheric interference. X-band circularly polarized antennas are core components of satellite TT&C systems; their circular polarization effectively suppresses the Faraday rotation effect, ensuring the robustness of the link under complex spacecraft attitudes. However, traditional microstrip TT&C antennas generally suffer from narrow ARBWs (Average Radial Bandwidths). In extreme conditions such as the initial orbital insertion phase or significant attitude deviations, narrow ARBWs lead to rapid deterioration of polarization purity, causing signal fading. Therefore, achieving a wide ARBW is more engineering-valued than simply pursuing axial ratio bandwidth and is crucial for ensuring stable wide-area spatial coverage. Furthermore, with increasing mission complexity, a single beam is no longer sufficient to meet the demands of complex communication environments and high-capacity communication. Summary of the Invention

[0003] The purpose of this invention is to provide a satellite telemetry and control antenna to solve at least some of the above-mentioned problems.

[0004] The present invention provides a satellite telemetry and control antenna, comprising a radiating patch layer, a first dielectric substrate, a ground layer, a second dielectric substrate, and a feed network layer. The radiating patch layer is attached to the upper surface of the first dielectric substrate, the ground layer is disposed between the lower surface of the first dielectric substrate and the upper surface of the second dielectric substrate, and the feed network layer is attached to the lower surface of the second dielectric substrate. The radiating patch layer is composed of several ring-shaped arrays of unconnected spiral patch units. Each of the spiral patch units is connected to the power supply network layer through a metal via post. The metal via post penetrates the first dielectric substrate, the ground layer, and the second dielectric substrate.

[0005] Furthermore, both the first dielectric substrate and the second dielectric substrate are circular dielectric substrates, the ground layer is a circular metal plate with the same shape as the circular dielectric substrate, and the center of the annular array of the plurality of spiral patch units is the center of the first dielectric substrate.

[0006] Furthermore, the spiral patch unit is provided with a power supply hole, which is electrically connected to the metal through hole. The power supply hole is located between the head and tail ends of the spiral patch unit. The distances between the power supply holes of several spiral patch units and the center of the annular array are all the same.

[0007] Furthermore, the spiral patch unit is formed by connecting the head end endpoint structure, the inner edge curve, the tail end endpoint structure, and the outer edge curve end to end in a closed manner. The inner edge curve r1 satisfies: r1 = a + b·t; The outer edge curve r2 satisfies: r2=a+Wp+b·t; Where a is the initial radius of the spiral patch unit, b is the growth rate, t is the radius in radians, and Wp is the width of the spiral patch unit.

[0008] Furthermore, the head end endpoint structure is a straight line, and the tail end endpoint structure is a straight line or an arc.

[0009] Furthermore, the number of spiral patch units is four, and the four spiral patch units are arranged in a sequential rotational arrangement with a 90° gradient on the first dielectric substrate.

[0010] Furthermore, the satellite telemetry and control antenna also includes a third dielectric substrate, the upper surface of which is in contact with the lower surface of the first dielectric substrate, and the lower surface of which is in contact with the grounding layer.

[0011] Furthermore, the power supply network layer includes an input port, several output ports, and a power supply point. The input port is perpendicularly corresponding to the center of the annular array of several spiral patch units. The power supply point and several output ports are respectively connected to the input port, and several output ports are respectively connected to the corresponding metal via posts.

[0012] Furthermore, the output ports are connected to the input ports via different transmission line segments, and the different transmission line segments introduce different wavelength delays to achieve a phase gradient distribution.

[0013] Furthermore, when the number of the spiral patch units is four, the power supply network layer includes an input port, a power supply point, a first output port, a second output port, a third output port, a fourth output port, a first λ / 4 transmission line segment, a second λ / 4 transmission line segment, a third λ / 4 transmission line segment, and a 3λ / 4 transmission line segment, wherein the power supply point is connected to the input port; The output terminals of the input ports are respectively connected to the first λ / 4 transmission line segment and the 3λ / 4 transmission line segment. The output terminals of the first λ / 4 transmission line segment are respectively connected to the first output port and the second λ / 4 transmission line segment. The output terminals of the second λ / 4 transmission line segment are connected to the second output port. The output terminals of the 3λ / 4 transmission line segment are respectively connected to the third output port and the third λ / 4 transmission line segment. The output terminals of the third λ / 4 transmission line segment are connected to the fourth output port.

[0014] The beneficial effects of this plan are as follows: The antenna significantly improves the ARBW width while ensuring impedance matching bandwidth by placing several helical dipole patches on a dielectric substrate and then feeding them through a feeding network. It also achieves efficient circularly polarized beam radiation to meet the urgent needs of modern aerospace missions for high-performance and high-reliability telemetry and control terminals.

[0015] This satellite telemetry and control antenna features extremely wide circularly polarized beam coverage: an ARBW of up to ±70° and a beamwidth of up to ±70° (the beamwidth of a conical beam antenna). It achieves coverage with an axial ratio better than 5 dB within an ultra-wide viewing angle of ±70°, a performance far exceeding traditional dipole or single-patch structures, and can meet the large-angle tracking requirements of next-generation low-Earth orbit satellites or mobile telemetry and control terminals. During satellite transits or rapid adjustments to the carrier's attitude, this antenna effectively ensures the stability of the communication link and significantly reduces signal fading caused by polarization mismatch. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a traditional rectangular microstrip patch antenna array; Figure 2 This is a schematic diagram of an Archimedes spiral segment antenna array; Figure 3 This is an exploded view of the satellite telemetry and control antenna in one embodiment; Figure 4 This is a top view of a satellite telemetry and control antenna in one embodiment; Figure 5 This is a schematic diagram of the bottom surface of a satellite telemetry and control antenna in one embodiment; Figure 6 This is a schematic diagram of a partial structure of the power supply network layer; Figure 7 A schematic diagram of the current in the Archimedes spiral segment dipole patch; Figure 8 Radiation pattern of the Archimedes spiral segment dipole patch; Figure 9 The image shows the simulation results of the antenna at a specific angle; Figure 10 The simulation results of the S-parameter amplitude of the feeder network are shown in the figure. Figure 11 The figure shows the S-parameter phase simulation results of the feeder network; Figure 12 Simulation and measured radiation patterns of the X-band receiving and control antenna; Figure 13 Simulation and measured radiation patterns of the X-band transmission and control antenna; Figure 14 This is a schematic diagram illustrating the communication performance of a satellite telemetry and control antenna.

[0017] Explanation of reference numerals in the attached figures: 10. Radial patch layer; 11. Spiral patch unit; 12. Feed via; 20. First dielectric substrate; 30. Ground layer; 40. Second dielectric substrate; 50. Third dielectric substrate; 60. Feed network layer; 61. Input port; 62. Feed point; 63. First output port; 64. Second output port; 65. Third output port; 66. Fourth output port; 67. First λ / 4 transmission line segment; 68. Second λ / 4 transmission line segment; 69. Third λ / 4 transmission line segment; 610. 3λ / 4 transmission line segment; 70. Metal via post. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0019] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "front," "rear," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention; the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "joined" should be interpreted broadly, for example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or they can refer to the internal communication of two components. For those skilled in the art, the specific meaning of the terms in this invention can be understood according to the specific circumstances.

[0020] Figure 1 This visually demonstrates the topology optimization process of antenna radiating elements evolving from traditional dipole patches to Archimedean spiral segments. Traditional microstrip patch antenna arrays... Figure 1 The radiation characteristics of a conventional microstrip array are limited by the standing wave current distribution at the patch edges. Although a circularly polarized field can be effectively constructed near the center frequency through vector synthesis of spatial geometric rotation and feed phase delay in a sequentially rotated (SR) feeding architecture, the surface current path length is fixed due to the narrowband resonant characteristics of conventional patches. Off-center frequencies, the amplitude balance and phase orthogonality between elements rapidly mismatch, limiting the ARBW (Average Resonance Wave Width). Furthermore, the mutual coupling effect between elements under broadband scanning easily causes pattern distortion and gain roll-off.

[0021] In contrast, in traditional surface mount designs, the current is confined to oscillations within limited geometric boundaries, making dynamic reconstruction of the effective radiation area impossible. To address these limitations, this paper introduces... Figure 2 The Archimedean spiral radiating element is shown. This structure utilizes the geometric characteristic that the arm length increases linearly with the angle to achieve adaptive adjustment of the current path with frequency. Based on the "active region" theory of traveling-wave antennas, low-frequency components propagate along the spiral arms to the outer edge for radiation, while high-frequency components complete radiation in the inner ring. This frequency-independent characteristic allows the antenna to maintain a constant input impedance and radiation pattern across an ultra-wide bandwidth. From the perspective of polarization purity, the spiral structure naturally possesses the physical property of generating circularly polarized waves. This frequency-independent characteristic enables the antenna to maintain a stable input impedance and radiation pattern over a wide bandwidth. Simultaneously, the spiral structure suppresses higher-order modes and cross-polarization through a smooth traveling-wave current distribution, ensuring polarization purity from a physical mechanism.

[0022] This design approach, under the same SR drive, exhibits performance advantages distinctly different from traditional structures. Comparing the two structures reveals that the axial ratio bandwidth of traditional arrays is often limited by the narrow-band resonance of the individual elements, while the Archimedes spiral array achieves octave band or even wider ARBW coverage. More importantly, the frequency independence of the spiral structure ensures minimal gain ripple across a wide bandwidth, and sidelobe levels are effectively controlled. Because the spiral elements provide a more linear phase response, the electric field vectors generated by the four elements can be more stably superimposed during sequential rotation synthesis, avoiding the axial ratio degradation caused by phase nonlinearity at the bandwidth edges in traditional structures. This achieves excellent broadband performance while maintaining high gain. This design optimization significantly improves the overall performance of the antenna and is a key strategy for overcoming the bottleneck of broadband circular polarization.

[0023] Specifically, see Figure 3-6 This embodiment discloses a satellite telemetry and control antenna, including a radiating patch layer 10, a first dielectric substrate 20, a ground layer 30, a second dielectric substrate 40, a third dielectric substrate 50, and a feed network layer 60. The radiating patch layer 10 is attached to the upper surface of the first dielectric substrate 20. The ground layer 30 is disposed between the lower surface of the first dielectric substrate 20 and the upper surface of the second dielectric substrate 40. The feed network layer 60 is attached to the lower surface of the second dielectric substrate 40. The radiating patch layer 10 is composed of a plurality of ring-arrayed, non-connected spiral patch units 11. The spiral patch units 11 are connected to the feed network layer 60 through metal through-hole posts 70. The metal through-hole posts 70 penetrate the first dielectric substrate 20, the ground layer 30, and the second dielectric substrate 40. The upper surface of the third dielectric substrate 50 is in contact with the lower surface of the first dielectric substrate 20, and the lower surface of the third dielectric substrate 50 is in contact with the ground layer 30.

[0024] The thickness of the radiating patch layer 10, the ground layer 30, and the bottom feed network layer 60 is t. The system is printed on a Rogers RO4003C dielectric substrate with a relative permittivity of 3.55 and a loss tangent of 0.0027.

[0025] This SR feed architecture based on transmission line difference significantly reduces the circuit area and the total insertion loss of the feed network compared to the cascaded 3-dB bridge structure. Finally, the top-layer spiral patch unit 11 and the bottom-layer phase-shifting output port are electrically connected through vertical metal vias passing through the dielectric substrate. This connection method ensures direct coupling of the feed signal while utilizing the shielding effect of the ground plane to isolate parasitic radiation from the feed network, enabling the antenna to maintain stable circular polarization characteristics and high-gain radiation performance over an extremely wide frequency band.

[0026] Specifically, the first dielectric substrate 20, the second dielectric substrate 40 and the third dielectric substrate 50 are all circular dielectric substrates, the ground layer 30 is a circular metal plate with the same shape as the circular dielectric substrate, and the center of the annular array of a plurality of spiral patch units 11 is the center of the first dielectric substrate 20.

[0027] The third dielectric plate 50 is provided to increase the thickness between the first dielectric plate 20 and the ground plane.

[0028] In the design of sequentially rotating arrays, circular substrates offer better rotational symmetry, effectively suppressing edge diffraction and surface wave scattering caused by sharp corners, thereby stabilizing the radiation phase center of each array element across a wide frequency band. Furthermore, the circular boundaries help reduce the contribution of asymmetric mutual coupling to the cross-polarization components, which is crucial for extending ARBW (Automatic Radiation Wave).

[0029] In one embodiment, the spiral patch unit 11 is provided with a power supply hole 12, which is electrically connected to a metal through-hole. The power supply hole 12 is located between the head end and the tail end of the spiral patch unit 11. The distance between the power supply holes 12 of several spiral patch units 11 and the center of the annular array is the same.

[0030] It should be emphasized that the spiral patch unit 11 of this scheme adopts tap feeding. A "tap" point is led out on the spiral patch unit 11. This point is not the starting point of the spiral, but a point after the starting point has been turned up a short distance. A feeding hole 12 is set at this point to connect to a metal through hole, so that a depression appears in the middle of the beam to better adapt to the coverage of satellite and earth communication.

[0031] In one embodiment, the spiral patch unit 11 is formed by connecting the head end endpoint structure, the inner edge curve, the tail end endpoint structure, and the outer edge curve end to end. The inner edge curve r1 satisfies: r1 = a + b·t; The outer edge curve r2 satisfies: r2 = a + Wp + b·t; Where a is the initial radius of the spiral patch unit 11, b is the growth rate, t is the radius in radians, and Wp is the width of the spiral patch unit 11. Where t∈[01, 02], 01= 0.5, 02 = 2.

[0032] Furthermore, the head end endpoint structure is a straight line, and the tail end endpoint structure is a straight line or an arc.

[0033] In one embodiment, four spiral patch units 11 are arranged in a sequential rotational arrangement with a 90° gradient on the first dielectric substrate 20. Of course, this solution is not limited to four spiral patch units 11; fewer than four units result in less significant effects, while more than four units generally provide better performance. Given that a large number of units complicates the power supply network design, four spiral patch units 11 are preferred.

[0034] See Figure 4 Based on precise calculations and experiments, the parameter values ​​of the X-band transmitting antenna structure in this embodiment are as follows: The thickness of the first dielectric substrate 20 is 1.524 mm, the thickness of the second dielectric substrate 40 is 0.503 mm, and the thickness of the third dielectric substrate 50 is 0.813 mm. The radius R of the three dielectric substrates is 93.4 mm.

[0035] a is 4.9mm, b is 10mm, and Wp is 7.8mm.

[0036] The horizontal distance Lx from the power supply hole 12 to the center of the circle is 9mm, and the vertical distance Ly from the power supply hole 12 to the center of the circle is 3mm.

[0037] This design employs the radiation characteristics of a conical beam to achieve stable coverage over a wide area. The conical beam creates a shallow notch directly above the antenna (θ=0°) and redistributes radiated energy to a large-angle region (θ=±70°), thereby providing flat and high-gain circularly polarized coverage over a wide viewing angle.

[0038] From the perspective of the physical mechanism of a single radiating unit, the Archimedes spiral segment introduced in this chapter can be equivalent to a symmetrically deformed, bent dipole. According to classical electromagnetic theory, the far-field radiation pattern function of a centrally fed ideal linear oscillator of finite length L in the E-plane (i.e., the plane containing the polarization direction) can be expressed as:

[0039] Where k = 2π / λ is the free-space wavenumber, and θ is the angle between the far-field observation point and the vertical axis. When the equivalent electric length L of the oscillator is less than λ / 2, the radiation fields are in phase at the axial direction θ = 0° due to the highly consistent phase of the surface currents, exhibiting a standard single-peak wide-beam shape. However, when the equivalent electric length L increases to approximately 1.5λ with increasing frequency or geometric path extension, the current on the oscillator surface will exhibit a multi-antinode characteristic with reverse distribution along the path. This reverse current distribution generates phase cancellation of the electric field vector in the far-field axial direction (θ = 0°), resulting in axial radiation traps that force the main beam to split into large-angle regions on both sides, forming a double-peak radiation pattern. For the Archimedean spiral segment element designed in this chapter, due to its frequency-adaptive "active region," its equivalent electric length L... eff It exhibits unique degrees of controllability. By finely optimizing the initial radius *a* and growth rate *b* of the spiral arm, the element can be made to excite higher-order current modes within the target X-band frequency band, giving it a natural multi-lobe radiation envelope. To further synthesize the multi-lobe characteristics of the element into an ideal, axially symmetrical conical beam and precisely control the elevation gain and axial notch depth, this design introduces spatial interferometric synthesis technology. Taking a binary subarray symmetrically distributed along the x-axis with a center-to-center spacing of *d* as an example, its total field distribution E total It can be obtained from the element pattern E ele Spatial array factor The product is derived as follows:

[0040] Where β represents the feed excitation phase difference between the two units. In this design, an excitation phase difference is set to construct destructive interference along the axial direction. (i.e., anti-phase feeding). At this point, by optimizing the center-to-center spacing d of the cells to approximately 0.9λ, the phase compensation point of the array factor is precisely guided to the large elevation angle region. In the vertical axis, the anti-phase excitation signal experiences complete destructive interference of its electric field vector due to the zero spatial path difference, achieving zero-point gain control. In the high elevation angle region, the spatial path difference compensates for part of the phase delay caused by β, allowing the radiation fields of each cell to satisfy the constructive interference condition, thereby achieving a spatial redistribution and superposition enhancement of energy.

[0041] Through full-wave electromagnetic simulation optimization guided by the above theory, the relative positions and geometric parameters of each radiating element in the four-element sequential rotating array were finally determined. For example... Figure 7-8 As shown, when the geometric widening of the helical segment satisfies the equivalent resonant path and achieves precise electromagnetic matching with the unit spacing d, the radiation pattern of the antenna successfully evolves from the traditional single-peak pointing to a highly symmetrical double-peak (conical) shape at a specific angle.

[0042] like Figure 9 As shown, simulation results demonstrate that this design enables efficient reconstruction of electromagnetic energy in space: near the extreme point θ=±70°, the beam achieves strong phase length superposition through spatial interference, with the simulated gain consistently exceeding 4 dBic, perfectly meeting the stringent requirements of the telemetry and control system for wide-area, large-angle signal coverage. More importantly, by suppressing inter-unit coupling and fine-tuning the geometric mismatch, the notch depth directly above the antenna is successfully limited to a reasonable range, and the axial gain is controlled above -2 dBic using the principle of incomplete phase cancellation. This optimization effectively avoids the dead zones in satellite-to-ground communication caused by excessively deep null points in conventional anti-phase arrays, preventing signal interruptions caused by excessively deep notches and expanding the spatial coverage margin. This lays a solid foundation for robust all-weather radiation performance for next-generation low-Earth orbit satellites under misaligned conditions.

[0043] In one embodiment, to achieve high-performance circularly polarized radiation over a wide bandwidth, a sophisticated one-to-many sequential phase-shifting power divider network is designed at the bottom layer. The feed network layer 60 includes an input port 61, several output ports, and a feed point 62. The input port 61 is perpendicularly aligned with the center of the annular array of several spiral patch units 11. The feed point 62 and several output ports are connected to the input port 61, and the several output ports are connected to corresponding metal via posts 70. A high-frequency SMA connector is soldered between the feed point 62 and the input port 61.

[0044] This structure utilizes a pure microstrip line topology to achieve equal power distribution and linear phase gradient, which not only effectively compresses the physical size but also utilizes the frequency response characteristics of the transmission line to achieve broadband matching.

[0045] In one embodiment, several output ports are connected to input port 61 through different transmission line segments. Different transmission line segments introduce different wavelength delays to achieve a phase gradient distribution.

[0046] In one embodiment, when the number of spiral patch units 11 is four, the power supply network layer 60 includes an input port 61, a power supply point 62, a first output port 63, a second output port 64, a third output port 65, a fourth output port 66, a first λ / 4 transmission line segment 67, a second λ / 4 transmission line segment 68, a third λ / 4 transmission line segment 69, and a 3λ / 4 transmission line segment 610, with the power supply point 62 connected to the input port 61; The output terminals of input port 61 are connected to the first λ / 4 transmission line segment 67 and the third λ / 4 transmission line segment 610, respectively. The output terminal of the first λ / 4 transmission line segment 67 is connected to the first output port 63 and the second λ / 4 transmission line segment 68, respectively. The output terminal of the second λ / 4 transmission line segment 68 is connected to the second output port 64. The output terminals of the third λ / 4 transmission line segment 610 are connected to the third output port 65 and the third λ / 4 transmission line segment 69, respectively. The output terminal of the third λ / 4 transmission line segment 69 is connected to the fourth output port 66.

[0047] In this power supply network, the control logic for phase compensation and power distribution is physically decoupled. This embodiment, based on microstrip line transmission theory, elaborates on its design principles in detail. First, the output phase is primarily controlled by the electrical length of the transmission line. According to planar transmission line theory, wave propagation in a microstrip line follows a propagation constant. ,in To guide the wavelength. When the signal travels through a physical length of When the transmission line is in a certain state, the resulting phase shift θ can be expressed as: ; Precise phase shifts can be obtained by setting the length differences between each branch. For example, if the first output port 63 is set as the reference... Then, a segment is added to the second output port 64. A 4 / 4 microstrip line is used to generate a 90° delay, and an additional segment is added to the third output port 65. A 4 / 4 microstrip line is used to generate a 180° delay. This phase control method based on wavelength difference exhibits good linearity over a wide bandwidth. Secondly, the power distribution ratio is primarily determined by the characteristic impedance (linewidth) of the transmission line. The characteristic impedance of the microstrip line... It is inversely proportional to its width W. At the T-junction or branch node of the power dividing network, power distribution follows the admittance distribution law. For an input impedance of... At a given node, the current intensity distributed to each branch depends on the input impedance of that branch. In this design, to achieve equal amplitude distribution, the width W of the microstrip line needs to be adjusted to match specific impedance transformation requirements. For example, a quarter-wavelength impedance transformer can be used to achieve a 50Ω to 100Ω matching: ; By properly setting the width of each transmission line segment, reflections caused by impedance mismatch can be minimized, ensuring that energy is transmitted equally to all four output ports. In summary, the electrical length of the transmission line is used for phase tuning, and the line width is used for power distribution management.

[0048] By properly setting the width of each transmission line segment, reflections caused by impedance mismatch can be minimized, ensuring that energy is transmitted equally to all four output ports. In summary, the electrical length of the transmission line is used for phase tuning, and the line width is used for power distribution management.

[0049] To achieve circular polarization and wide-beam radiation in conjunction with the aforementioned Archimedes spiral array, the network needs to provide an excitation signal with constant amplitude and a phase gradient of 90° within the target center frequency band. The specific implementation scheme employs hierarchical power-sharing logic: the input signal is first equally divided into two branches at the backbone node, and then enters path A (first output port 63, second output port 64) and path B (third output port 65, fourth output port 66), respectively. A phase gradient distribution is achieved by introducing a precisely calculated wavelength delay into each transmission line segment. Figure 10-11 The simulation results of the S-parameters of the network are presented. As can be seen from the figure, near the center frequency, the transmission coefficient at the output port... , ,| ,| The amplitude remained stable at around -6.2 dB. Considering the theoretical value of an ideal four-port power divider is -6 dB, the additional 0.2 dB insertion loss mainly comes from the dielectric loss of the Rogers RO4003C substrate and the conductor loss of the microstrip line. In terms of phase response, the four ports exhibited good sequential gradients, with phase deviation controlled within a small range, which provides a basis for the array in... Maintaining a low aspect ratio within a wide-angle range lays the theoretical foundation.

[0050] Figure 12 The measured results of the antenna's normalized radiation pattern at the center frequency are presented. The figure shows that the antenna exhibits a distinct wide-beam radiation characteristic, with energy effectively superimposed over large angle regions. The measured data show that the antenna at the target angle... The gain in the vicinity is better than 4 dBic, meeting the requirement of wide coverage. Simultaneously, utilizing the interference effect generated by differential excitation, directly above... The directional gain was controlled at around -2 dBic to avoid signal interruption caused by deep nulls in the radiation pattern. Furthermore, the circular polarization performance of the antenna was experimentally verified. Actual measurements of the AR in an anechoic chamber showed that the simulation and experimental results were largely consistent. It exhibits extremely high consistency within the field of view. The measured ARBW covers the target frequency band and maintains good circular polarization purity in the wide-angle range.

[0051] Based on the above design architecture, the antenna prototype was fabricated and analyzed through testing. The receiving antenna operates within a bandwidth of 7.1 GHz to 7.5 GHz. All values ​​are better than -10 dB, and its impedance bandwidth covers the expected receiving frequency band. At the center frequency of 7.25 GHz, the measured radiation pattern is in high agreement with the theoretical prediction, exhibiting good wide-beam characteristics. Figure 13 As shown, in At the target elevation angle, a gain better than 4 dBic is achieved, while in the normal direction ( In the direction of polarization, it outperforms by more than -2 dBic, effectively ensuring robust signal coverage in the hemispherical space. Regarding circular polarization purity, the measured ARBW... The gain remained below 5 dB throughout the range. Comparison with simulation data revealed a slight decrease in measured gain, and slight fluctuations in the axial ratio curve at the frequency band edges. Analysis suggests this is primarily due to impedance discontinuities caused by manually soldered SMA connectors, and a slight increase in the substrate's loss coefficient at low frequencies.

[0052] By optimizing the geometric parameters a and b of the Archimedean spiral segment, the antenna design achieves an axial ratio better than 5 dB within an ultra-wide viewing angle of ±70°. This performance far surpasses that of traditional dipole or single-patch structures, meeting the large-angle tracking requirements of next-generation LEO satellites and mobile telemetry and control terminals. The wide-angle axial ratio characteristics of this design align with the large-angle tracking requirements of next-generation LEO satellites and mobile telemetry and control terminals. During satellite transits or rapid attitude adjustments of the carrier, this antenna effectively ensures the stability of the communication link and significantly reduces signal fading caused by polarization mismatch. From a broader perspective of technological development, the parameterized optimization-based Archimedean spiral structure design method proposed in this paper solves a specific engineering challenge.

[0053] This scheme significantly improves the circular polarization robustness of the unit by evolving the traditional patch antenna into an Archimedean spiral segment, utilizing the traveling wave radiation mechanism and frequency-independent characteristics of the spiral structure. Combined with a 1-to-4 sequential phase-shift feed network based on the electrical length difference of microstrip transmission lines, the system exhibits excellent electromagnetic characteristics in both the transmit and receive frequency bands. Experimental results show that the antenna achieves a large-angle coverage with a beamwidth of ±70° near the center frequency, with a gain better than 4 dBic at the target elevation angle, normal gain compensation exceeding -2 dBic, and stable axial ratio performance over a large angle range. Figure 14 As shown, the implementation of a wide-beam antenna design not only multiplies channel capacity through polarization multiplexing, but also provides greater airspace coverage margin, significantly improving the survivability of miniaturized satellites in misaligned states and reducing the dependence of attitude adjustment on the propulsion system.

[0054] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A satellite telemetry and control antenna, characterized in that, It includes a radiating patch layer, a first dielectric substrate, a ground layer, a second dielectric substrate, and a power supply network layer. The radiating patch layer is attached to the upper surface of the first dielectric substrate, the ground layer is disposed between the lower surface of the first dielectric substrate and the upper surface of the second dielectric substrate, and the power supply network layer is attached to the lower surface of the second dielectric substrate. The radiating patch layer is composed of several ring-shaped arrays of unconnected spiral patch units. Each of the spiral patch units is connected to the power supply network layer through a metal via post. The metal via post penetrates the first dielectric substrate, the ground layer, and the second dielectric substrate.

2. The satellite telemetry and control antenna according to claim 1, characterized in that, Both the first dielectric substrate and the second dielectric substrate are circular dielectric substrates. The ground layer is a circular metal plate with the same shape as the circular dielectric substrate. The center of the annular array of the plurality of spiral patch units is the center of the first dielectric substrate.

3. The satellite telemetry and control antenna according to claim 1, characterized in that, The spiral patch unit is provided with a power supply hole, which is electrically connected to the metal through hole. The power supply hole is located between the head end and the tail end of the spiral patch unit.

4. The satellite telemetry and control antenna according to claim 1, characterized in that, The spiral patch unit is formed by connecting the head end endpoint structure, the inner edge curve, the tail end endpoint structure, and the outer edge curve end to end in a closed manner. The inner edge curve r1 satisfies: r1 = a + b·t; The outer edge curve r2 satisfies: r2=a+Wp+b·t; Where a is the initial radius of the spiral patch unit, b is the growth rate, t is the radius in radians, and Wp is the width of the spiral patch unit.

5. The satellite telemetry and control antenna according to claim 4, characterized in that, The head end endpoint structure is a straight line, and the tail end endpoint structure is a straight line or an arc.

6. The satellite telemetry and control antenna according to claim 1, characterized in that, The number of spiral patch units is four, and the four spiral patch units are arranged in a sequential rotational arrangement with a 90° gradient on the first dielectric substrate.

7. The satellite telemetry and control antenna according to claim 1, characterized in that, The satellite telemetry and control antenna also includes a third dielectric substrate, the upper surface of which is in contact with the lower surface of the first dielectric substrate, and the lower surface of which is in contact with the grounding layer.

8. The satellite telemetry and control antenna according to claim 1, characterized in that, The power supply network layer includes an input port, several output ports, and a power supply point. The input port is perpendicular to the center of the annular array of several spiral patch units. The power supply point and several output ports are respectively connected to the input port, and several output ports are respectively connected to the corresponding metal via posts.

9. The satellite telemetry and control antenna according to claim 8, characterized in that, The output ports are connected to the input ports through different transmission line segments, and the different transmission line segments introduce different wavelength delays to achieve a phase gradient distribution.

10. The satellite telemetry and control antenna according to claim 9, characterized in that, When the number of spiral patch units is four, the power supply network layer includes an input port, a power supply point, a first output port, a second output port, a third output port, a fourth output port, a first λ / 4 transmission line segment, a second λ / 4 transmission line segment, a third λ / 4 transmission line segment, and a 3λ / 4 transmission line segment, and the power supply point is connected to the input port; The output terminals of the input ports are respectively connected to the first λ / 4 transmission line segment and the 3λ / 4 transmission line segment. The output terminals of the first λ / 4 transmission line segment are respectively connected to the first output port and the second λ / 4 transmission line segment. The output terminals of the second λ / 4 transmission line segment are connected to the second output port. The output terminals of the 3λ / 4 transmission line segment are respectively connected to the third output port and the third λ / 4 transmission line segment. The output terminals of the third λ / 4 transmission line segment are connected to the fourth output port.

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