RU2807961C1 - Low profile composite satellite antenna - Google Patents

Abstract

FIELD: antenna devices.

SUBSTANCE: used for receiving and transmitting satellite frequency signals with circular polarization on stationary and moving objects. The result is achieved by proposing a receiving/transmitting low-profile composite satellite antenna of circular polarization, containing a controller, stepper motors in azimuth and elevation, two or more parabolic truncated reflectors, feeders according to the number of reflectors, each of which contains a polarizer and a subreflector, and has two inputs/outputs for signals of the left L and right R polarizations, respectively, and the signals from the feeders through single-mode waveguides of rectangular cross-section are supplied to the side inputs of T-shaped adders/dividers, and between the waveguides and the side inputs of the adders/dividers there are inserts that act as phase shifters for accurate matching the phases of the signals, while signals L and R are formed at the central terminals of the adders/dividers, which are also the inputs/outputs of the antenna.

EFFECT: reduction in the dimensions of the antenna and an increase in the gain of the received/transmitted signal.

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Description

The invention relates to the field of antenna means and can be used for receiving/transmitting a satellite frequency signal with circular polarization on both stationary and moving objects, for example, on airplanes, land and water transport, on trains, etc.

The needs for SOTM (Satcom-On-The-Move) mobile satellite communication services are constantly growing, and to meet them, it is necessary to organize high-speed channels with improved electrodynamic characteristics and small equipment dimensions.

Improvements in the transmit-receive equipment used on communications satellites such as HTS (High Throughput Satellites) are delivering more powerful beams to the ground, allowing the use of electromechanically beam-controlled antennas with stringent weight and size requirements. In turn, this contributes to the creation of low-profile antenna systems for equipping various types of vehicles with satellite communications.

One of the directions for solving the problem of creating low-profile antenna systems is the use of truncated parabolic reflectors, which are easy to manufacture and have small dimensions.

Known [1 - Patent RU No. 2799107 "Low-profile phased satellite antenna", publ. 07/04/2023, Bulletin. No. 19], containing n passive microstrip structures consisting of dielectric plates, on the surface of which metal passive elements are located, and the plates are fastened to each other, and the passive elements, starting from the first plate from the bottom, are shifted in one direction, a metal grounding plate on the top on the surface of which a dielectric with active microstrip elements is fixed, which forms an active ordered structure, and on the lower surface supply probes are brought out, which have an electrical connection with the active elements, signals from the probes enter the first multichannel group waveguide with disturbance elements, with each waveguide channel in the lower part has one via hole for signal output, characterized in that the second and third multi-channel group waveguides, a device for adjusting the physical length of delay lines and group adders of left and right polarization signals are introduced into it. The disadvantages of this antenna are the complexity of manufacturing and low signal gain.

Known [2 - US Patent No. 9,318,810 B2 "Ring focus antenna" with priority April 2, 2015] is an antenna for use in mobile and portable satellite antenna systems, which is capable of receiving/transmitting signals with circular and linear polarization. The antenna includes a concave parabolic-shaped main reflector having a focal circle around its axis. A circular waveguide horn extends from the main reflector concentrically to this axis. A sub-reflector is installed behind the distal end of the waveguide horn, and an annular gap remains between the sub-reflector and the distal end of the circular waveguide horn. The disadvantage of this antenna is the low signal gain and high profile height.

Known [3 - Antenna system SOTM 0.6 m Ku-band TISHZH..468331.220 low-profile parabola of circular polarization. URL: http://www.rc-tech.ru/%D0%A2%D0%98%D0%A8%D0%96.468331.220%20%D0%A0%D0%AD%20%D0%90%D0 %A1%20SOTM%200.6%20%D0%BC%20Ku-%D0%B4%20%D1%87%D0%B0%D1%81%D1%82%D0%BE%D1%82.pdf] , containing an antenna control unit, a 0.55 m Ku-band antenna, a reflector, a counter-reflector, a feed with a polarization adjustment device, stepper motors, a rotary support device, a radio-transparent dome, an antenna control controller, a divider/adder, a low-noise Ku-band unit ( LNB), gyroscope, GLONASS/GPS receiver, power supply and designed to provide high-speed communication channels on the move. The disadvantages of this antenna system are the low signal gain and large height dimensions.

It is known [4 - Patent RU No. 2296397 C2 “Antenna-feeder device and antenna included in this device.” Publ. March 27, 2009, Bull. No. 9.], containing four parabolic antennas located in the same plane, the matching device is made on the basis of dividers. The input and four outputs of the matching device are made through sections of a two-mode transmission line. The input is connected to the four outputs via single-mode transmission line segments. The dividers are located in the same plane. The two side arms of each of the dividers are connected to adjacent outputs, and the central arms on four sides are connected to the input of the matching device. Phase shifters. The power dividers are made in the form of T-shaped joints. The disadvantage of this antenna is its large dimensions, namely the large height of the side profile.

The purpose of the invention is to reduce the dimensions of the antenna along the profile height and increase the gain of the received/transmitted signal. This is achieved by the fact that the antenna contains two or more independent parabolic reflectors (mirrors) truncated (with reduced dimensions), the design of feeds with sub-reflectors and adders of received signals from each reflector.

The claimed set of elements, forms of execution and connections makes it possible to achieve the set goal through an original combination of instruments and devices used in telecommunication networks, both in their direct and non-standard applications.

The invention is illustrated graphically (to simplify the description, an antenna consisting of two reflectors is shown):

In FIG. 1. shows a general view of the antenna from the front.

In FIG. 2. - Waveguide assembly with adders/dividers (rear view).

The low-profile composite satellite antenna includes the first 1 and second 2 reflectors (mirrors), the first 3 and second 4 sub-reflectors, the first 5 and second 6 feeds, 7 stiffeners, 8 stands, a rotation axis of 9 reflectors in elevation, a 10 stepper motor for azimuthal rotation, gear 11, gear 12, stepper motor 13, gear 14, drive 15, controller 16, plate 17, platform 18, base 19, dome 20, waveguides 21, first 22 and second 23 adders/dividers, waveguide channels L - 24 and 25, waveguide channels R - 26 and 27, first 28 and second 29 polarizers (depolarizers), inserts (phase shifters) 30, input/output L - 31 and input/output R - 32.

Reflectors 1 and 2 are truncated on all sides in order to reduce the overall dimensions of the antenna, the first 3 and second 4 sub-reflectors are made of an asymmetrical shape and are equipped with enlarged upper and lower peripheral ears (extensions) in accordance with the known principles of geometric optics and taking into account the geometry of the poured surface of the reflectors. The first 5 and second 6 feeds have two waveguide channels for the left L - 24, 25 and right R - 26, 27 polarizations, respectively. Depending on the material, the mirrors have two or more stiffeners 7. The posts 8 are located on both sides of the antenna and are attached at the base to a platform 18, which rotates in azimuth using a stepper motor 10, a gear 11 and a gear 12, which, in turn, attached to the fixed base 19 of the antenna. The reflectors rotate relative to the axis 9 in elevation using a stepper motor 13, a gear 14 and a drive 15 in the form of, for example, a toothed belt. Moreover, the stepper motors 10 and 13 are fixed on the plate 17. On the movable platform 18 there is a controller 16 for controlling the antenna. The first 5 and second 6 feeds have polarizers 28 and 29, for example, in the form of step-shaped plates, which convert the circular polarization signal into left L and right R longitudinal wave signals, respectively. Moreover, the L signals through the upper waveguides 21 are supplied to the side inputs of the first T-shaped waveguide adder/divider 22, and the R signals through the lower waveguides 21 are supplied to the side inputs of the second T-shaped waveguide adder/divider 23. Between the side inputs of the first 22 and In the second 23 adders/dividers and waveguides 21 there are inserts 30, which are designed to change the geometric dimensions of the waveguides 21 in order to accurately regulate the phase of the signals. The total signals L and R are supplied to the inputs/outputs L 31 and R 32 of adders/dividers 22 and 23, respectively, which are also inputs/outputs of the antenna.

One example of manufacturing a feed with a polarizer is the “Two-mirror antenna” patent RU No. 2474936. Publ. 02/10/2013, Bulletin. No. 14".

Reflectors 1 and 2 are made by rotating a parabolic generatrix around the axis of rotation, and the focus of the parabolic generatrix is located outside the axis of rotation, and subreflectors 3 and 4 are made by rotating an elliptical generatrix around the same axis of rotation, the tops of the subreflectors are facing the mirror, and one of the focuses of the elliptical generatrix is located on axis of rotation, and the feed for each antenna is located on the axis of rotation between the parabolic surface and the subreflector.

The inserts 30 are metal plates with a rectangular cutout in the center, corresponding to the size of the waveguide 21 and a thickness of, for example, 0.2 mm. Selecting the length of the side arm by changing the number of inserts performs the function of phase regulation. Moreover, the inserts are transferred from one shoulder to another in order to maintain the overall geometry of the structure. Phase shifters can also be made, for example, by changing the dimensions of rectangular waveguides in the side arms of the T-junctions, using dielectric plates installed in the side arms of the T-junctions, or other known methods

The mirrors, waveguide assembly with irradiators and stiffening ribs are fixed on a plate 17 made, for example, of an aluminum alloy. In this case, the fastening and connection of structural elements is carried out by any known method. The entire antenna structure is covered from above by a radio-transparent dome 20, which is attached to the base 19 of the antenna.

To ensure satellite search and tracking, the antenna may additionally include electronic devices, such as a low-noise block (LNB), a gyroscope, a navigation receiver, a power supply and others.

The antenna works as follows.

To simplify the description, consider a composite antenna containing, for example, two - the first and second reflectors (mirrors).

When searching for a satellite, the antenna moves in azimuth and elevation according to a certain algorithm. After tuning the antenna to the satellite, the signal from the latter arrives at the first and second main reflectors, from where it reaches the first and second sub-reflectors, respectively, and through the first and second feeds enters the waveguide assembly (structure), with the help of polarizers located in the feeds at the outputs the latter we receive signals of the left L and right R polarizations in the form of a longitudinal wave. Signals of left-hand polarization L arrive at the side inputs of the first waveguide T-shaped adder/divider, from the input/output of which we receive the total signal of left-hand polarization L from two mirrors. Similarly, from the input/output of the second waveguide T-shaped adder/divider, we obtain the total right-hand polarization signal R from two mirrors. Moreover, for precise phase matching, between the side inputs of the first and second adders/dividers and the waveguides, for example, inserts of the required thickness are located, which change the geometric size of the waveguide assembly.

Similar to the operation of the receiving path, a signal can be transmitted to a satellite, while the signal from an external source is supplied to the inputs/outputs of the first and second waveguide T-shaped adders.

Since the first and second reflectors are truncated, this results in the antenna radiation pattern being uneven in the radial direction relative to the central axis. To take into account this effect, using well-known techniques of geometric optics, the first and second sub-reflectors are made of asymmetrical shape and are equipped with enlarged peripheral ears or extensions, which takes into account the absence of truncated parts of the reflectors and allows reducing the levels of dissipative losses in the transmission mode and parasitic noise in the reception mode.

To further increase the signal amplification factor, the dimensions (mainly the height) of the reflectors are increased, and if there is a limitation, then the number of reflectors is increased. For example, if one or more reflectors are added, then, accordingly, additional feeds with polarizers and subreflectors and T-shaped adders/dividers with corresponding waveguides and inlays are introduced.

The side profile of the moving part of the antenna when rotating along the elevation angle has a sweep diameter that does not exceed the specified height dimensions. In this case, the antenna structure with reflectors and feeds, mounted on the holding plate, will fit into a cylinder, the height and length of which determine the total volume of the antenna sweep.

Thus, the use of two or more truncated parabolic reflectors makes it possible to produce a low-profile satellite antenna with a given gain. For example, an antenna of two reflectors with a gain equivalent to a symmetrical parabola with a diameter of 50 cm has a height of about 21 cm and a sweep diameter of about 100 cm.

The invention meets the criterion of “inventive step”, since it includes a set of essential features with corresponding connections, namely truncated reflectors, irradiators with polarizers, elongated saddle-shaped subreflectors, taking into account the geometry of truncated reflectors, adders/dividers with a set of inserts, a controller, azimuth stepper motors and angle of location.

The technical solution is new, since the specified set of essential features makes it possible to produce a satellite antenna with a low profile and high gain, which, in turn, allows the antenna to be installed on moving objects with strict requirements for weight and size characteristics.

The inventive low-profile composite satellite antenna can be implemented using existing hardware and equipment, electrical and communications equipment, telecommunications equipment, and computer technology and is “industrially applicable.”

Information sources

1. Patent RU No. 2799107 "Low-profile phased satellite antenna", publ. 07/04/2023, Bulletin. No. 19.

2. US Patent No. 9,318,810 B2 "RING FOCUS ANTENNA" with priority 04/2/2015

3. Antenna system SOTM 0.6 m Ku-band TISHZH..468331.220 low-profile parabola of circular polarization. URL: http://www.rc-tech.ru/%D0%A2%D0%98%D0%A8%D0%96.468331.220%20%D0%A0%D0%AD%20%D0%90%D0 %A1%20SOTM%200.6%20%D0%BC%20Ku-%D0%B4%20%D1%87%D0%B0%D1%81%D1%82%D0%BE%D1%82.pdf.

4. Patent RU No. 2296397 C2 “Antenna-feeder device and antenna included in this device,” publ. 03.27.2009, Bull. No. 9. (prototype).

Claims (3)

1. A low-profile composite satellite antenna containing two or more reflectors, each of which is made by rotating a parabolic generatrix around an axis of rotation, with the focus of the parabolic generatrix located outside the axis of rotation, and the subreflector is made by rotating an elliptical generatrix around the same axis of rotation, the top of the subreflector facing mirror, one of the foci of the elliptical generatrix is located on the axis of rotation, and the feed for each antenna is located on the axis of rotation between the parabolic surface and the subreflector, T-shaped adders/dividers, each of which is made in the form of a connection of symmetrical single-mode waveguides, characterized in that that it contains a controller, stepper motors in azimuth and elevation, and the reflectors have a truncated shape, and polarizers are introduced into the feeds, which have two inputs/outputs for signals of the left L and right R polarizations, respectively, with the signals from the feeds through single-mode waveguides rectangular cross-section are supplied to the side inputs of the T-shaped adders/dividers, where the in-phase summation of the mentioned signals from the reflectors occurs, and the central terminals of the T-shaped adders/dividers are the antenna inputs/outputs. 2. Low-profile composite satellite antenna according to claim 1, characterized in that the sub-reflectors have an asymmetric, elongated saddle-shaped shape, taking into account the geometry of truncated reflectors. 3. Low-profile composite satellite antenna according to claim 1, characterized in that inserts of a certain thickness are introduced between the side inputs of the T-shaped adders/dividers and the waveguides, the transfer of which from one arm to the other allows you to accurately adjust the phases of the addition signals.

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