L-band self-tracking feed network with coaxial feed

Abstract

The application discloses an L frequency band self-tracking feed source network adopting coaxial feed, and belongs to the technical field of satellite communication microwave antennas; the L frequency band receiving signal is transmitted along the axial direction of a shaped metal outer wall, eight stepped coaxial probes are symmetrically distributed along the axial direction of a dielectric rod at an angle of 45 degrees, one end of each of the coaxial probes is inserted into the shaped metal outer wall, and the other end of each of the coaxial probes is connected with a difference signal polarization synthesis network through a cable, the difference signal polarization synthesis network outputs two L frequency band TE21 mode circular polarization signals, four mushroom-shaped coaxial probes are symmetrically distributed along the axial direction of the dielectric rod at an angle of 90 degrees, one end of each of the coaxial probes is inserted into the shaped metal outer wall, and the other end of each of the coaxial probes is connected with a sum signal polarization synthesis network through a cable, and the sum signal polarization synthesis network outputs two L frequency band circular polarization signals. The shaped metal outer wall provides support for the coaxial probes. The application has the advantages of small volume, light weight, no need of debugging, large amount of manpower cost saved, and suitability for engineering promotion.

Description

Technical Field

[0001] This invention discloses an L-band self-tracking feed network using coaxial feeding, which relates to the field of satellite communication microwave antenna technology and is suitable for L-band signal reception of fixed station and mobile station antennas to achieve antenna self-tracking. Background Technology

[0002] Satellite communication boasts numerous advantages, including wide coverage, flexible networking, and lack of geographical limitations, leading to its widespread application in both military and civilian fields. As an emergency communication method for disaster prevention, relief, and handling emergencies, satellite communication holds significant promise. L-band antennas have long been widely used in various important fields such as broadcasting, civil aviation, and emergency communications. The L-band feed network is the core component of the antenna, and its performance largely depends on the performance of the antenna itself. However, due to the low frequency of the L-band, traditional feed networks are bulky and cannot be used with 2.3m diameter antennas, limiting their application scenarios.

[0003] Self-tracking feed networks are the core components of telemetry, tracking, and communication satellite feed systems. Currently, the most commonly used multi-mode tracking system both domestically and internationally is the TE21 mode, which has high tracking accuracy and is widely used in satellite communication and telemetry fields. However, the L-band has a low frequency, and traditional feed networks are bulky and difficult to lay out. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a simple, easily fabricated L-band feed with self-tracking functionality. This invention includes a shaped metal outer wall, a mushroom-shaped coaxial probe for signal transmission, a signal polarization combining network, a stepped coaxial probe for differential signal transmission, a differential signal polarization combining network, and a connecting cable. The designed compact L-band self-tracking dielectric feed network is simple in structure, requires no debugging, is low in cost, and easy to fabricate. It can meet the requirements for receiving L-band signals (1.67GHz-1.71GHz) and tracking TE21 mode. The feed pattern has a large illumination angle and can be used for front-feed antenna illumination. This invention also features a compact structure, small size, light weight, convenient operation, and low manufacturing cost. It can be installed on antennas with a diameter of 2.3m or larger, and has a wide range of applications.

[0005] The objective of this invention is achieved as follows:

[0006] A self-tracking feed network for L-band coaxial feeding includes a stepped shaped metal outer wall, four mushroom-shaped coaxial probes for sum signals, a polarization synthesis network for sum signals, eight stepped coaxial probes for difference signals, and a polarization synthesis network for difference signals.

[0007] The sum signal polarization synthesis network and the difference signal polarization synthesis network are both sleeved on the outside of the constricted portion of the stepped shaped metal outer wall; four mushroom-shaped coaxial probes for the sum signal are symmetrically distributed at 90° axially along the outer surface of the constricted portion of the stepped shaped metal outer wall; one end of the mushroom-shaped coaxial probe is inserted into the shaped metal outer wall, and the other end is connected to the sum signal polarization synthesis network through a cable;

[0008] Eight differential signal stepped coaxial probes are symmetrically distributed at 45° axial angle along the outer surface of the flared portion of the stepped shaped metal outer wall. One end of the differential signal stepped coaxial probe is inserted into the shaped metal outer wall, and the other end is connected to the differential signal polarization synthesis network through a cable.

[0009] Furthermore, the constricted and flared portions of the stepped shaped metal outer wall are smoothly transitioned to give the feed radiation pattern a large illumination angle.

[0010] Furthermore, the outer side of the flange of the aforementioned coaxial probe with the signal mushroom shape is an N-50K connector, and the inner side of the flange sequentially includes a metal rod and a metal mushroom head connected to the end of the metal rod, with the metal rod and the metal mushroom head connected by threads.

[0011] Furthermore, the outer side of the flange of the differential signal stepped coaxial probe is an N-50K connector, and the inner side of the flange contains two metal cylinders, wherein the diameter of the metal cylinder closer to the flange is smaller than the diameter of the metal cylinder farther from the flange, and the length of the metal cylinder closer to the flange is greater than the length of the metal cylinder farther from the flange.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] 1. This invention uses a shaped metal outer wall to transmit L-band sum and difference signals. By changing the shape of the metal outer wall, the standing wave and radiation pattern of the feed network and the sum and difference signals can be adjusted, thereby controlling the performance of the antenna.

[0014] 2. The present invention uses a stepped coaxial probe for the differential signal as a connection device for the feed differential signal polarization synthesis network, which has a simple structure and is easy to process.

[0015] 3. The present invention uses a mushroom-shaped coaxial probe as the connection device between the feed source and the signal polarization synthesis network, which has a simple structure and is easy to process.

[0016] 4. The differential signal polarization synthesis network adopts a microstrip form, which has a simple structure and small size. It is connected to the feed source by a cable, and the placement of the differential signal polarization synthesis network can be freely controlled by adjusting the cable length.

[0017] 5. The signal polarization synthesis network adopts a microstrip form, which has a simple structure and small size. It is connected to the feed source through a cable, and the placement of the signal polarization synthesis network can be freely controlled by adjusting the cable length.

[0018] 6. This invention is small in size and light in weight, requires no debugging, can save a lot of manpower costs, and can quickly realize the assembly of L-band feed network system, making it suitable for mass production. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the present invention.

[0020] Figure 2 This is a schematic diagram of the shaped metal outer wall described in this invention.

[0021] Figure 3 This is a schematic diagram of the mushroom-shaped coaxial probe for signaling described in this invention.

[0022] Figure 4 This is a schematic diagram of the differential signal stepped coaxial probe described in this invention.

[0023] Figure 5 This is a block diagram illustrating the principle of the signal polarization synthesis network described in this invention.

[0024] Figure 6 This is a block diagram of the differential signal polarization synthesis network principle described in this invention.

[0025] Explanation of reference numerals in the attached figures: shaped metal outer wall—1, mushroom-shaped coaxial probe for sum signal—2, mushroom-shaped coaxial probe for difference signal—3, polarization synthesis network for sum signal—4, polarization synthesis network for difference signal—5. Detailed Implementation

[0026] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings.

[0027] A coaxial-fed L-band self-tracking feed network includes a shaped metal outer wall, four mushroom-shaped coaxial probes for sum signals, a sum signal polarization combining network, eight stepped coaxial probes for difference signals, and a difference signal polarization combining network. The L-band received signal is transmitted backward along its axis. The eight stepped coaxial probes are symmetrically distributed at 45° along the axis of the shaped metal outer wall, with one end inserted into the outer wall and the other end connected to the difference signal polarization combining network via a cable. The difference signal polarization combining network outputs two L-band TE21 mode circularly polarized signals. The four mushroom-shaped coaxial probes are symmetrically distributed at 90° along the axis of the shaped metal outer wall, with one end inserted into the outer wall and the other end connected to the sum signal polarization combining network via a cable. The sum signal polarization combining network outputs two L-band circularly polarized signals. The shaped metal outer wall provides support for the coaxial probes and allows adjustment of the feed pattern.

[0028] The shaped metal outer wall is stepped, serving as a support for the probe and allowing adjustment of the feed pattern. It has four circular openings symmetrically distributed at 90° along the axial direction for inserting a mushroom-shaped coaxial probe for the signal and a flange for connecting to the signal coaxial probe. It also has eight circular openings symmetrically distributed at 45° along the axial direction for inserting a stepped coaxial probe for the differential signal and a flange for connecting to the differential signal coaxial probe.

[0029] The differential signal stepped coaxial probe has an N-50K connector above the flange and two metal cylinders with different radii below the flange. One end of the cylinder is inserted into the outer wall of the shaped metal, and the other end is connected to the differential signal polarization synthesis network via a cable.

[0030] The sum signal mushroom-shaped coaxial probe has an N-50K connector above the flange, and a metal rod and a metal mushroom head below the flange. The metal rod and the metal mushroom head are connected by threads, with one end inserted into the shaped metal outer wall and the other end connected to the sum signal polarization synthesis network via a cable. The difference signal polarization synthesis network consists of eight cables connected to the difference signal stepped coaxial probe, outputting two ports. Internally, it employs a microstrip circuit design, using a 180-degree bridge, a 90-degree bridge, and a load to output left-hand and right-hand rotary signals of the TE21 mode. The difference signal polarization synthesis network has an irregular shape design, allowing for a tight connection with the shaped metal outer wall, reducing the size of the feed network system.

[0031] The sum signal polarization synthesis network consists of four cables connected to a mushroom-shaped coaxial probe for the sum signal, outputting two ports. Internally, it employs a microstrip circuit design, using a 180-degree bridge, a 90-degree bridge, and a load to output left-hand and right-hand spiral signals for the sum signal. The network's irregular shape allows for close integration with the shaped metal outer wall, reducing the overall size of the feed network system.

[0032] The cable is used for the connection between the differential signal stepped coaxial probe and the differential signal polarization synthesis network, and for the connection between the signal mushroom-shaped coaxial probe and the signal polarization synthesis network.

[0033] This L-band self-tracking feed network, employing coaxial feeding, utilizes a shaped metal outer wall and two types of coaxial probes to transmit L-band sum and difference signals. It integrates two polarization synthesis networks, resulting in a compact structure suitable for installation on smaller aperture antennas. The stepped shaped metal outer wall provides a large illumination angle for the feed radiation pattern, making it suitable for front-feed antenna illumination and enabling single-pulse self-tracking. This feed network system is small in size, lightweight, requires no debugging, saves significant labor costs, and is suitable for engineering deployment.

[0034] Specifically, such as Figure 1As shown, the L-band self-tracking feed network using coaxial feeding includes a shaped metal outer wall, four mushroom-shaped coaxial probes for the sum signal, one polarization synthesis network for the sum signal, eight stepped coaxial probes for the difference signal, one polarization synthesis network for the difference signal, and twelve connecting cables. Figure 2 The outer wall of the shaped metal has four circular openings that are symmetrically distributed at 90° around the axis of the dielectric rod and are connected to the mushroom-shaped coaxial probe for the sum signal. It also has eight circular openings that are symmetrically distributed at 45° around the axis of the dielectric rod and are connected to the stepped coaxial probe for the difference signal. The stepped shape of the outer wall of the shaped metal gives the feed radiation pattern a large illumination angle.

[0035] Furthermore, such as Figure 3 The image shows a mushroom-shaped coaxial probe for signals. Above the probe flange is an N-50K connector, and below the flange are a metal rod and a metal mushroom head. The metal rod and the metal mushroom head are connected by threads. One end is inserted into the shaped metal outer wall, and the other end is connected to the signal polarization synthesis network via a cable.

[0036] Furthermore, such as Figure 4 The image shows a stepped coaxial probe for differential signals. Above the probe flange is an N-50K connector, and below the flange are two metal cylinders with different radii. One end is inserted into the outer wall of the shaped metal, and the other end is connected to the differential signal polarization synthesis network via a cable.

[0037] Furthermore, such as Figure 5 The diagram shows the sum signal polarization synthesis network, which consists of four cables connected to a mushroom-shaped coaxial probe for the sum signal. It outputs two ports and employs a microstrip circuit design. Left-hand and right-hand rotation signals are output through a 180-degree bridge, a 90-degree bridge, and a load. The network's irregular shape allows for close integration with the shaped metal outer wall, reducing the overall size of the feed network system.

[0038] Furthermore, such as Figure 6 The diagram shows the differential signal polarization synthesis network, which consists of eight cables connected to a stepped coaxial probe for the differential signal. It outputs two ports and employs a microstrip circuit design. Left-hand and right-hand differential signal outputs are achieved through 180-degree and 90-degree bridges, and loads. The differential signal polarization synthesis network has an irregular shape that allows for close integration with the shaped metal outer wall, reducing the overall size of the feed network system.

[0039] In summary, the L-band self-tracking feed network using coaxial feeding includes a shaped metal outer wall, four mushroom-shaped coaxial probes for sum signals, a sum signal polarization combining network, eight stepped coaxial probes for difference signals, and a difference signal polarization combining network. This feed network system enables the reception of L-band dual-circular polarized sum and difference signals. This invention has advantages such as compact structure, ease of fabrication, and excellent electrical performance, making it suitable for the needs of L-band fixed and mobile station antennas.

Claims

1. An L-band self-tracking feed network using coaxial feeding, characterized in that, Operating at a frequency of 1.67GHz-1.71GHz, it achieves TE21 mode self-tracking and is compatible with antennas with a diameter of 2.3m or larger. It includes a stepped shaped metal outer wall, four mushroom-shaped coaxial probes for the sum signal, a polarization synthesis network for the sum signal, eight stepped coaxial probes for the difference signal, and a polarization synthesis network for the difference signal. The sum signal polarization synthesis network and the difference signal polarization synthesis network are both sleeved on the outside of the constricted portion of the stepped shaped metal outer wall; four mushroom-shaped coaxial probes for the sum signal are symmetrically distributed at 90° axially along the outer surface of the constricted portion of the stepped shaped metal outer wall; one end of the mushroom-shaped coaxial probe is inserted into the shaped metal outer wall, and the other end is connected to the sum signal polarization synthesis network through a cable; Eight differential signal stepped coaxial probes are symmetrically distributed at 45° axial angle along the outer surface of the flared portion of the stepped shaped metal outer wall. One end of the differential signal stepped coaxial probe is inserted into the shaped metal outer wall, and the other end is connected to the differential signal polarization synthesis network through a cable. The outer side of the flange of the aforementioned coaxial probe with the signal mushroom shape is an N-50K connector, and the inner side of the flange contains a metal rod and a metal mushroom head connected to the end of the metal rod. The metal rod and the metal mushroom head are connected by threads. The flange of the differential signal stepped coaxial probe has an N-50K connector on the outside and two metal cylinders on the inside. The diameter of the metal cylinder closer to the flange is smaller than the diameter of the metal cylinder farther from the flange, and the length of the metal cylinder closer to the flange is greater than the length of the metal cylinder farther from the flange.

2. The L-band self-tracking feed network with coaxial feeding according to claim 1, characterized in that, The stepped shaped metal outer wall has a smooth transition between the constricted and flared sections, which is used to give the feed radiation pattern a large illumination angle.

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