A compact feed tracking network

Abstract

The application discloses a compact feed tracking network, and belongs to the technical field of satellite communication and space measurement and control antenna. The ring cavity feed is a ring-shaped open cavity structure, the and signal feed is located at the center position of the ring cavity feed, and the central axes of the two coincide; the bottom of the ring cavity feed is provided with a short circuit surface as an excitation signal; the upper surface of the short circuit surface is embedded with a multilayer microwave dielectric plate structure; the multilayer microwave dielectric plate structure is mainly composed of upper and lower two dielectric plates; the upper surface of the upper dielectric plate is uniformly provided with eight printed board strip line probes, each printed board strip line probe penetrates the wall surface of the ring cavity feed and points to the geometric center of the and signal feed. 21 Eight-channel microwave signal synthesis.

Description

Technical Field

[0001] This invention relates to the core component TE for single-pulse tracking in the fields of satellite communication and aerospace telemetry and control antenna technology. 21 Mode Coupler Technology, TE 21 Mode couplers are commonly used microwave devices, primarily applied in the feed networks of high-precision tracking antennas. Their operating frequency bands include both microwave and millimeter-wave bands. However, failure to meet antenna installation size requirements directly hinders the effective improvement of system performance. Background Technology

[0002] Conventional implementation of TE 21 The mode field distribution method employs an eight-arm waveguide coupling configuration. The advantages of this method are low loss and high transmitted signal power; the disadvantages are large structural size, complex wiring, and high manufacturing and debugging costs.

[0003] To solve this technical problem, coaxial cable-driven power dividers and TE converters with 90-degree phase-shifting bridges were developed. 21 The mode-coupled device (MCD) feed network is characterized by its smaller size compared to waveguide synthesis networks, resulting in reduced cost. However, it suffers from drawbacks: a cluttered, non-integral design, unsuitability for specialized applications, and potential amplitude and phase deviations during assembly, leading to degraded electrical performance. In small-aperture antenna systems, for TE... 21 The physical dimensions of mode couplers impose more stringent technical requirements. Traditional waveguide synthesis and cable synthesis methods for TE... 21 Neither of the mode coupler methods can meet the antenna installation size requirements, directly hindering the effective improvement of system performance.

[0004] Traditional TE 21 Coupler type: Eight rows of longitudinally arranged coupling holes are opened on the side wall of the main waveguide, and the network synthesizer is transmitted by waveguide transmission lines. Its characteristics are differential mode pattern equalization and high illumination efficiency. Its disadvantages are limited bandwidth, usually around 20%, and the synthesized network occupies a large space, which cannot meet the requirements of small space application.

[0005] The subsequent development of this technology will mean that conventional electrical design will no longer be TE 21 The main problems with mode couplers, and consequently the issues of wide bandwidth and miniaturization, are the primary focus of research in recent years, both domestically and internationally. This has led to the development of coaxial TE couplings. 21 Modular coupler structure.

[0006] From an application perspective, due to its mature implementation technology and high tracking accuracy, TE 21 Analog single-pulse diodes remain the preferred choice in many situations. Therefore, integrated TE... 21 The successful development and standardization of mode couplers have great potential for engineering applications.

[0007] The aforementioned research can largely solve the existing technical problems under conventional structural space conditions. However, when the antenna aperture is small, the bandwidth is wide, and the network layout of external network devices is limited, traditional connection methods cannot meet the technical requirements. Therefore, to address this technical need, there is an urgent need to research TE networks with wideband, compact, and integrated feeder networks. 21 Coupler technology meets engineering needs. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of existing technologies and propose a compact electromagnetic structure for tracking networks. The radiating structure is externally positioned around the main radiating waveguide, forming a ring-shaped cavity structure. This significantly reduces the physical size of the external structure, enabling TE to be completed within a limited physical space. 21 Eight-channel microwave signal synthesis.

[0009] The specific solution of the present invention is as follows:

[0010] A compact feed tracking network includes a signal feed 1 and a ring cavity feed 2; the ring cavity feed has an annular open cavity structure, the signal feed is located at the center of the ring cavity feed, and the central axes of the two coincide; the bottom of the ring cavity feed is provided with a short surface as an excitation signal;

[0011] The upper surface of the short road surface is embedded with a multi-layer microwave dielectric substrate structure 3; the multi-layer microwave dielectric substrate structure is mainly composed of upper and lower dielectric substrates; the upper surface of the upper dielectric substrate is evenly distributed with 8 printed circuit board line probes, each of which penetrates the wall of the ring cavity feed source and points to the geometric center of the signal feed source.

[0012] The eight printed circuit board trace probes are divided into two groups, with the trace probes in the same group arranged at intervals; any two adjacent trace probes in the same group are connected to the output of a single-to-four combiner through the same phase delay line.

[0013] One set of printed circuit board trace probes and the phase delay lines and quad combiners connected to them are located on the upper surface of the upper dielectric substrate.

[0014] Another set of printed circuit board trace probes are connected to a phase delay line and a 1-to-4 combiner located on the lower surface of the lower dielectric substrate through metal vias I that penetrate the upper and lower dielectric substrates.

[0015] The signal output terminal of the one-to-four combiner on the upper surface of the upper dielectric substrate is connected to the input terminal of the microstrip line 9 located on the lower surface of the lower dielectric substrate through a metal via II that passes through both the upper and lower dielectric substrates. The signal from the microstrip line and the signal output terminal of the one-to-four combiner on the lower surface of the lower dielectric substrate enter the two input terminals of the 90° bridge 10 located on the lower surface of the lower microwave dielectric substrate. The 90° bridge 10 is a four-port microstrip line network used to achieve the function of equal amplitude and 90° phase difference between the two signals.

[0016] Furthermore, the aperture end of the annular cavity feed source is coplanar with the radiation port end of the signal feed source.

[0017] Furthermore, the main body of the printed circuit board line probe is an extension of the upper printed circuit board toward the annular cavity feed source; the upper surface of the extension is copper-clad.

[0018] Furthermore, the phase delay line is used to achieve a 180° phase difference between adjacent printed circuit board trace probes in the same group; adjacent printed circuit board trace probes in the same group enter the input terminal of the single-to-four combiner with equal amplitude and a 180° phase difference.

[0019] Furthermore, the copper plating on the extension does not contact the wall of the annular cavity feed source.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] This invention innovatively uses a cavity feed 2 positioned around the signal feed 1, and employs a printed circuit board (PCB) stripline probe to excite the cavity feed 2 to generate directional radiation. Signals from the one-to-four combiner are transmitted via metal vias to microstrip lines 9 on the lower surface of the lower PCB, where they are combined with signals from the one-to-four combining network on the lower PCB. This avoids the technical challenge of crossover between the two networks on the same layer. Finally, the combined signals are transmitted to a 90-degree bridge, and then output via an RF connector to the tracking receiver, achieving TE... 21 Construction of differential mode field models. This invention has a clear design concept, is easy to implement, and solves the problems of traditional TE... 21 The complex wiring structure and large space occupation problem have been solved by integrating the design of the network and radiation structure, constructing the radiation electromagnetic structure, and the microwave network wiring is an innovative improvement on the existing single-pulse feed tracking technology. Attached Figure Description

[0022] To more clearly describe this patent, one or more drawings are provided below, which are intended to assist in illustrating the background technology, technical principles and / or certain specific embodiments of this patent.

[0023] Figure 1 This is the three-dimensional structure of the tracking network feed source in this embodiment of the invention;

[0024] Figure 2 This is a diagram showing the distribution of the upper-layer network of the tracking network feed in an embodiment of the present invention;

[0025] Figure 3 This is a diagram showing the distribution of the underlying network of the tracking network feed in this embodiment of the invention.

[0026] Figure 4 This is a side view of the lower layer network of the tracking network feed in an embodiment of the present invention; Detailed Implementation

[0027] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0028] This embodiment takes the following considerations:

[0029] First, a ring cavity radiator surrounding the signal feed is proposed, which achieves good electromagnetic compatibility with the signal feed. Compared with the traditional technique of coupling signals on the waveguide wall, this method ensures the optimal design of the signal feed while satisfying the requirement of tracking signal extraction.

[0030] Second, a power supply method for exciting the ring cavity by printed circuit board stripline probes is proposed, which couples out the radiation field of a single signal. Eight printed circuit board stripline probes are evenly distributed around the ring cavity, realizing the signal excitation of eight signals in the circle.

[0031] Third, a multi-layer dielectric substrate feed network combined with via vertical interconnect technology is proposed to achieve cross-connection-free network feeds for 8-port signals, realizing TE 21 Physical construction of the model field;

[0032] Based on the key technologies of the above invention, the structural composition of the compact feed tracking network component is described in detail.

[0033] The signal feed 1 has a rotationally symmetrical structure and can be a light wall horn, a corrugated horn, or other types of feed sources. This patent does not limit the specific feed source.

[0034] A ring cavity feed 2 is provided on the outer side of the circumference of the signal feed 1. The geometric center axis of the ring cavity feed 2 is coaxial with the geometric center axis of the signal feed 1. The opening end of the ring cavity feed 2 is set at the same height as the radiation port end of the signal feed 1.

[0035] Furthermore, the annular cavity feed 2 has an annular cavity structure, and a metal isolation wall is provided between it and the signal feed 1;

[0036] Furthermore, the bottom of the ring cavity feed 2 is a closed design, which serves as a short-circuit surface for the excitation signal, allowing the electromagnetic signal to radiate unidirectionally along the opening direction of the ring cavity feed.

[0037] A multilayer microwave dielectric substrate 3 is embedded above the short road surface at the bottom of the ring cavity feed 2. It has a ring structure and consists of two dielectric substrates, an upper and a lower layer, and is equipped with a metal ground layer, a signal stripe layer, and metal vias.

[0038] Furthermore, eight printed circuit board probe structures are provided on the multilayer microwave dielectric substrate 3, with their extension direction pointing towards the geometric center of the signal feed source 1.

[0039] The eight printed circuit board line probes are part of the structure of the upper layer of the multilayer microwave dielectric board. The upper surface of the upper dielectric board is a copper-clad metal probe structure, while the lower surface is not copper-clad metal.

[0040] The eight printed circuit board trace probes are sequentially numbered and described as (1) to (8). The signals from the printed circuit board trace probes (1), (3), (5), and (7) enter the four-in-one circuit 5, and the signals from the printed circuit board trace probes (2), (4), (6), and (8) enter the four-in-one circuit 6.

[0041] Furthermore, the signals of the printed circuit board line probe (1) and the printed circuit board line probe (3) are designed to be 180° out of phase by a phase delay line 4 set on the signal transmission path of the printed circuit board line probe (3). The two signals are of equal amplitude and 180° out of phase and enter the two input terminals of the one-to-four combiner 5. The signals of the printed circuit board line probe (5) and the printed circuit board line probe (7) have the same configuration. A phase delay line 4 is set on the signal transmission path of the printed circuit board line probe (7). The two signals are of equal amplitude and 180° out of phase and enter the other two input terminals of the one-to-four combiner 5.

[0042] Similarly, the printed circuit board trace probes (2), (4), (6), and (8) transmit signals to the lower surface of the lower layer of the multilayer printed circuit board 3 through four metal vias 7, thus avoiding overlap between the power supply networks; the signals of the printed circuit board trace probes (2), (4), (6), and (8) enter the quad-connector 6, and its network routing is the same as that of the quad-connector 5.

[0043] The signal output terminal of the one-to-four converter 5 transmits the signal to the microstrip line 9 on the lower surface of the lower microwave dielectric substrate through the metal via 8.

[0044] The signal in the microstrip line 9 and the signal output of the one-to-four combiner 6 enter the two input terminals of the 90° bridge 10 located on the lower surface of the lower microwave dielectric substrate.

[0045] The 90° bridge 10 is a four-port microstrip network that enables equal amplitude and 90° phase difference between two signals.

[0046] Two output ports feed into two RF connectors.

[0047] Reference Figures 1 to 4 The embodiments of the present invention are as follows:

[0048] The signal feed 1 has a rotationally symmetrical structure and is manufactured using CNC machining. Its aperture size D should be less than 1.8λ0 (λ0 is the wavelength corresponding to the working center frequency). The feed structure is not limited.

[0049] The signal feed 1 and the ring cavity feed 2 are designed as an integrated structure. The geometric center axis of the ring cavity feed 2 is coaxial with the geometric center axis of the signal feed 1. The aperture width W1 is approximately 1λ0, with a value range of ±5%. The depth h1 is greater than 0.3λ0, and it is ensured that the opening end of the ring cavity feed 2 is at the same height as the radiation port end of the signal feed 1.

[0050] The ring cavity feed 2 has a circular cavity structure. It is an integrated structure design with the signal feed 1 and is set at the top of the device as a radiation unit to realize the radiation function.

[0051] Furthermore, a multilayer microwave dielectric substrate 3 is embedded at a distance of 0.1λ0 to 0.15λ0 from the bottom of the annular feed 2. This substrate has an annular structure and is composed of an upper and lower printed circuit board bonded together. It consists of several metal ground layers, signal stripe layers, and metal vias. The multilayer microwave dielectric substrate 3 is a major component of the feed network of the feed system and completes the TE (Transmission Equipment) circuit. 21 Differential-mode signal power synthesis.

[0052] The multilayer microwave dielectric substrate 3 consists of two dielectric substrates, the upper and lower layers of which have a dielectric constant of 3.5, a thickness of 1 mm, and a loss tangent of 0.0017. The two printed circuit boards are bonded together using a 0.1 mm thick prepreg.

[0053] Furthermore, eight printed circuit board (PCB) line probe structures are disposed on the upper surface of the upper PCB layer of the multilayer microwave dielectric substrate 3. These are rectangular portions of the upper PCB extending into the inner cavity of the ring cavity feed 2. Their extension direction points towards the geometric center of the signal feed 1. The width of the PCB line probe is w2 = 0.4 mm to 1.2 mm, and the length extending into the inner cavity of the ring cavity feed 2 is l2 = 0.18λ0 to 0.23λ0. The length and width of the rectangular PCB portion are limited by the dimensions of the PCB line probes and do not affect electrical performance.

[0054] Eight printed circuit board probe structures are arranged at equal intervals around the circumference of the annular feed source 2.

[0055] Furthermore, a rectangular opening 12 is provided at the intersection of the ring cavity feed 2 and the printed circuit board stripline probe, which avoids the copper-clad structure of the printed circuit board stripline probe, realizing the transition from the stripline probe structure to the microstrip structure, and forming a quasi-microwave coaxial structure.

[0056] The eight printed circuit board trace probes are sequentially numbered and described as (1) to (8). The signals from the printed circuit board trace probes (1), (3), (5), and (7) enter the four-in-one circuit 5, and the signals from the printed circuit board trace probes (2), (4), (6), and (8) enter the four-in-one circuit 6.

[0057] Among them, the one-to-four combiner 5 and the one-to-four combiner 6 are Wilkinson power combiners in the form of microstrip line structures, which realize the power combining of signals.

[0058] Furthermore, the phase delay line 4 set on the microstrip line transmission path of the printed circuit board stripline probe (3) realizes the 180° phase difference design between the signal in the printed circuit board stripline probe (1) and the printed circuit board stripline probe (3). Finally, the two signals are in a state of equal amplitude and 180° phase difference and enter the two input terminals of the one-to-four combiner 1. The signals of the printed circuit board stripline probe (5) and the printed circuit board stripline probe (7) have the same settings. The phase delay line 4 is set on the signal transmission path of the printed circuit board stripline probe (7). The two signals are in a state of equal amplitude and 180° phase difference and enter the other two input terminals of the one-to-four combiner 1.

[0059] Similarly, the printed circuit board trace probes (2), (4), (6), and (8) transmit signals to the lower surface of the lower layer of the multilayer printed circuit board 3 through four metal vias 7, thus avoiding overlap between the power supply networks; the signals of the printed circuit board trace probes (2), (4), (6), and (8) enter the quad combiner 6, which is equipped with phase delay lines as well as the upper layer network, to achieve a 180-degree phase delay design for the printed circuit board trace probes (2) and (4) as well as the printed circuit board trace probes (6) and (8).

[0060] The signal output terminal of the one-to-four converter 5 transmits the signal to the microstrip line 9 on the lower surface of the lower microwave dielectric substrate through the metal via 8.

[0061] Furthermore, the metal vias pass through the metal ground layer on the lower surface of the upper dielectric substrate and the metal ground layer on the upper surface of the lower dielectric substrate, and a clearance design is required to prevent signal short circuits.

[0062] The signal from the microstrip line 9 and the output signal from the quad combiner 6 enter the two input terminals of the 90° bridge 10 located on the lower surface of the lower microwave dielectric substrate.

[0063] The 90° bridge 10 is a four-port microstrip network that enables equal amplitude and 90° phase difference between two signals.

[0064] The two output ports are equipped with coaxial connector 11 (this structure is shown in the figure and is common knowledge), which is used to input signals to the receiver.

[0065] The radiator structure (including signal feed 1 and ring cavity feed 2) and the multilayer microwave dielectric substrate 3 constitute the entire composition of the device.

[0066] The basic working principle of this device is as follows: Printed circuit board (PCB) stripline probes are fed into the inner cavity of the ring cavity feed source 2. An electromagnetic field is generated around the feedline, aligned with its extension direction, and effectively radiates into the self-contained space. Similarly, seven other PCB stripline probes excite electromagnetic fields with different polarization directions. The signals from these eight PCB stripline probes are combined through a feeding network on a multilayer microwave dielectric substrate to achieve equal amplitude, 180° phase difference, and ultimately equal amplitude and 90° phase difference, thus constructing a TE... 21 The field pattern is constructed, and the final output is a difference signal that satisfies the requirement of single-pulse tracking.

[0067] The above description is merely the preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A compact feed tracking network comprising a signal feed (1), characterized in that Also include ring cavity feed source (2); the ring cavity feed source is annular open cavity structure, the and signal feed source is located at the center position of ring cavity feed source, and the central axes of the two coincide; the bottom of the ring cavity feed source is provided with short circuit surface as excitation signal; The upper surface of the short circuit surface is embedded with a multilayer microwave dielectric plate structure (3); the multilayer microwave dielectric plate structure is composed of upper and lower two layers of dielectric plates; the upper surface of the upper layer of dielectric plates is uniformly distributed with 8 printed board strip line probes, each printed board strip line probe penetrates the wall surface of the ring cavity feed source and points to the geometric center of the and signal feed source; 8 printed board strip line probes are divided into two groups, and the printed board strip line probes in the same group are arranged at intervals; any two adjacent printed board strip line probes in the same group are connected with the output end of a four-way hybrid through the same phase delay line; One group of printed board strip line probes, the phase delay line connected thereto and the four-way hybrid are all located on the upper surface of the upper layer of dielectric plates; The other group of printed board strip line probes are connected with the phase delay line and the four-way hybrid located on the lower surface of the lower layer of dielectric plates through the metal via I penetrating the upper and lower layers of dielectric plates; The signal output end of the four-way hybrid on the upper surface of the upper layer of dielectric plates is connected with the input end of the microstrip line (9) located on the lower surface of the lower layer of dielectric plates through the metal via II penetrating the upper and lower layers of dielectric plates, and the signals of the microstrip line and the signal output end of the four-way hybrid on the lower surface of the lower layer of dielectric plates enter the two input ends of the 90° bridge (10) provided on the lower surface of the lower layer of dielectric plates, the 90° bridge (10) is in the form of four-port microstrip line network, and is used for realizing the functions of equal amplitude and 90° phase difference of two-way signals.

2. A compact feed tracking network according to claim 1, characterised in that, The open end of the ring cavity feed source is coplanar with the radiation port end of the and signal feed source.

3. A compact feed tracking network according to claim 1, wherein, The main body of the printed board strip line probe is the extension part of the upper layer of printed board towards the inside of the ring cavity feed source; the upper surface of the extension part is coated with copper.

4. A compact feed tracking network according to claim 1, wherein, The phase delay line is used for realizing 180° phase difference of the adjacent printed board strip line probes in the same group; the adjacent printed board strip line probes in the same group enter the input end of the four-way hybrid with equal amplitude and 180° phase difference.

5. A compact feed tracking network according to claim 3, wherein, The copper coating on the extension part is not in contact with the wall surface of the ring cavity feed source.

Images