EP3577719B1

EP3577719B1 - Telecommunications device

Info

Publication number: EP3577719B1
Application number: EP18707149.3A
Authority: EP
Inventors: Fabio ROSATO; Danilo MAZZEO
Original assignee: Fabbrica Italiana Antenne Faini Telecommunication Systems Srl
Current assignee: Fabbrica Italiana Antenne Faini Telecommunication Systems Srl
Priority date: 2017-02-02
Filing date: 2018-02-02
Publication date: 2022-04-06
Anticipated expiration: 2038-02-02
Also published as: WO2018142344A1; EP3577719A1

Description

TELECOMMUNICATIONS DEVICE

The present invention relates to a telecommunications device.
In particular, the invention relates to an antenna designed for high-capacity point-to-point, radio link communications.
Similar devices are comprised in patent applications US6005528A , US-A-2014057576 , US-A-5907309 US 2013/207742 A1 , and in document IMBRIALE W A ET AL: "Antennas for the array-based deep space network: current status and future designs", AEROSPACE CONFERENCE, 2005 IEEE, IEEE, PISCATAWAY, NJ, USA.
As is well known, conventional antennas are substantially adapted to receive and/or transmit electromagnetic signals.
In particular, these activities can be accomplished by virtue of the fact that the aforesaid antennas usually comprise a parabolic mirror or reflector that is adapted to pick up or send electromagnetic signals of desired frequencies.
In telecommunications, the demand for ever-increasing amounts of data to be transmitted per unit time has led telecommunications equipment manufacturers to develop equipment capable of working at higher and higher frequencies in order to have greater transmission/reception capacity.
In particular, E-band antennas are known in the current state of the art for high-frequency transmissions. These antennas are suitable to process signals within the frequency range of 71-76 GHz and 81-86 GHz and therefore have high data transmission capacity.
The described prior art has a few major drawbacks.
In particular, a limitation of E-band transmissions is given by signal attenuation effects related to the distance between the sites to be connected and caused by poor weather conditions such as rain and snow.
In fact, as is known, if on the one hand high-frequency electromagnetic waves allow the transmission of a large number of data, on the other they are highly sensitive to the length of the radio link, i.e. the point-to-point distance, and the obstacles they may encounter along the transmission path.
The reduced wavelength makes the signal less efficient over long ranges and reduces transmission robustness.
In order to make the E-band radio links more robust and reliable, those skilled in the art adopted a substantially constructive solution.
To compensate for the shortcomings of the E-band radio antennas, a second antenna is generally adopted, which is designed for receiving and transmitting signals at lower and therefore more stable frequencies, in order to have a safety connection capable of intervening in case of failure of the main antenna. However, even this solution has the serious drawback of having to add another antenna to the telecommunications system, thus considerably increasing the costs of the equipment and installation in the field, as well as the space required on the antenna-supporting structures, including towers, poles and other necessary equipment.
In this context, the technical task underlying the present invention is to devise a telecommunications device, which is capable of substantially obviating at least some of the above-mentioned drawbacks.
Within the scope of said technical task, a major object of the invention is to obtain a telecommunications device, which is robust over long ranges and in any weather conditions without the addition of auxiliary devices.
Another major object of the invention is to provide a device, which is simple to manufacture and has a simplified structure with respect to the solution suggested by the current state of the art.
In conclusion, a further object of the invention is to provide a telecommunications device, which allows the typical costs of the antennas operating in the current state of the art to be reduced.
The technical task and the specified objects are achieved by means of a telecommunications device as claimed in the appended claim 1. Preferred embodiments are described in the dependent claims.
The features and advantages of the invention will be apparent from the detailed description of preferred embodiments of the invention, with reference to the accompanying drawings, in which:

Fig. 1 shows the telecommunications device according to the invention in a single-polarization configuration connectable to two radios;
Fig. 2 shows a front view of the telecommunications device according to the invention;
Fig. 3 is a top view of the device according to the invention;
Fig. 4 shows the telecommunications device according to the invention in a dual-polarization configuration connected to three radios;
Fig. 5a shows a detail of the feed or receiver of a telecommunications device according to the invention as seen from the support;
Fig. 5b is a detail of the feed or receiver of a telecommunications device according to the invention as seen from the reflector;
Fig. 6 is a perspective view of the telecommunications device according to the invention in a dual-polarization configuration with a support for three radios;
Fig. 7 shows an exploded view of the controller including part of the feed of the device according to the invention;
Fig. 8 shows a detail of the second acquisition portion of the feed and the detail of the guide of the device according to the invention;
Fig. 9 is an exploded view of the controller showing the feed housing and the waveguides inside the circuit of the device according to the invention;
Fig. 10 depicts the controller of the device according to the invention and shows the overlapping circuits thereof.

In the present document, the measures, values, shapes and geometric references (such as perpendicularity and parallelism), when associated with terms like "about" or other similar terms such as "almost" or "substantially", are to be understood as unless measurement errors or inaccuracies due to production and/or manufacturing defects and, especially, unless a slight difference from the value, measure, shape, or geometric reference with which it is associated. For example, these terms, if associated with a value, preferably indicate a difference not exceeding 10% of the value itself.
Furthermore, when used, terms such as "first", "second", "higher", "lower", "main" and "secondary" do not necessarily identify an order, a priority relationship or a relative position, but can simply be used to distinguish more clearly the different components from each other.
The measurements and the data reported in this text are to be considered, unless otherwise indicated, as carried out in the International Standard Atmosphere ICAO
With reference to the Figures, the telecommunications device according to the invention is indicated as a whole by the numeral 1.
The telecommunications device 1 is adapted to transmit and receive electromagnetic signals, therefore is adapted to pick up electromagnetic waves that carry, for example, audio or video or still other information and data.
The device 1 comprises a reflector 2, a bidirectional "illuminator or feed" 3, and a support 4.
The reflector 2 defines an operating surface 20 adapted to direct the electromagnetic signals in and out.
Therefore, this operating surface 20 is, for example, a concave surface adapted to focus the data, or rather the electromagnetic waves at a point or in an area of said surface 20.
However, the surface 20 may have different shapes, provided that the full functionality required by the device 1 is guaranteed.
Preferably, the reflector 2 is a parabolic mirror with a diameter of at least 6 dm, and therefore the operating surface 20 is defined by the inside of the parabolic mirror as known in the current state of the art.
Preferably, furthermore, the reflector 2 is an aluminium parabolic mirror and includes an absorbent material "coating" in order to reduce the transmission and reception of signals for angles exceeding 50 degrees from the main connection axis. Moreover, the support 2 is constrained to the support 4 and is adapted to direct the electromagnetic signals in and out of the feed 3.
The feed 3, therefore, is preferably a device adapted to send and receive electromagnetic signals. It is particularly adapted to send and receive electromagnetic signals at different frequencies and is substantially a device known in the current state of the art.
It is preferably arranged partly on the operating surface 20 of the reflector 2 and partly inside the support 4. In addition, more in detail, it is arranged in the area where the reflector 2 focuses the input signals, and extends inside part of the support 4.
It is usually a corrugated feed for the lower frequency range, inside which there is a coaxial dielectric rod feed, or bar, for the E-band range. Such a structure, already known for satellite applications at lower frequencies, however, has been optimized to make it usable in the E-band range, as well as in the lower range, with a double reflector optics, where the second reflector or sub-reflector is an integral part of the dual-band feed design.
In fact, unlike conventional feeds, the feed 3 or receiver is a dual-band feed that can operate simultaneously in the e-band frequency range (71-86 GHz) and in a known band frequency range comprised between 17 and 40 GHz.
In the literature, for frequency rates this high, the physical dimensions of the guiding and radiating structures are different from each other with a scale factor of about 3 and with the consequent limitations related to the frequency bands allowed, whereas the device allows the provision of structures with a scale factor of about 5 or even higher. Furthermore, no telecommunications device, in particular radio links, due to structural reasons, is currently able to reach the maximum frequencies considered. Instead, advantageously, the feed 3 comprises at least a first acquisition portion 30 and a second acquisition portion 31.
The first acquisition portion 30 is adapted to receive high frequency signals, in particular of the E-band type, and comprises a well known hollow, substantially cylindrical conductor.
The second acquisition portion 31 is adapted to receive low frequency signals.
The second acquisition portion 31 is arranged coaxially with respect to the first acquisition portion 30. It also comprises at least one guide 31a.
The guide 31a is preferably a part of the second acquisition portion 31 in the shape of a truncated cone oriented so as to be converging from the reflector 2 to the support 4.
This guide 31a can be made with metal walls or it can be formed as a recess, for example, inside a portion of the support 4, as in Fig. 7.
The guide 31a comprises a plurality of slots 32.
In particular, the slots 32 are the end portion of the waveguides 34, with a rectangular section, which are arranged radially with respect to the axis defined by the receiver or feed 3, and hence by the first acquisition portion 30, extending axially along the side surface of the guide 31a.
The waveguides 34 are metallic waveguides arranged, in the portion next to the guide 31a, perpendicular to the side surface of the guide 31a and extending radially with respect to the axis of the second acquisition portion 31, and preferably perpendicularly to the surface of the acquisition portion 31.
Furthermore, the slots 32, and the waveguides 34 included therein, are connected to at least part of the support 4. More conveniently, the slots 32 and the waveguides 34 are housed inside part of the support 4, as shown in Fig. 7 and Fig. 9.
The slots 32 may be two, for example for a single-polarization configuration of the device 1, or may be more than two depending on other types of configurations.
In a dual-polarization configuration, the slots 32 are four and operatively connected two by two so as to route the input signals with two polarizations, preferably two crossed polarizations H and V, as shown in Fig. 8.
In addition, the guide 31a comprises a short-circuited portion 33.
The short-circuited portion 33 is arranged at the smaller base of the frustoconical portion. It is, for example, an annular wall made of a conductive material and arranged at the smaller base of the guide 31a around the first acquisition portion 30.
The minimum distance between the short-circuited portion 33 and the slots 32 is preferably less than 1 cm, more preferably less than 5 mm, still more preferably less than 2 mm. The short-circuited portion 33 is therefore preferably adjacent to the slots 32 and suitably equidistant from each of them.
The above-described second acquisition portion 31 allows transmission of the signal in the low range (18GHz or 23 GHz, etc.).
The first portion 30 preferably comprises a hollow cylinder operatively connected to at least part of the support 4. More suitably at least partly included in the support 4. The first portion 30 comprises an inner waveguide 35 consisting of the inner conductive layer of the coaxial cable, which allows transmission of the high range (e-band).
It should be noted that the inner waveguide 35 consists of a hollow metal cylinder and extends along the whole axis of the frustoconical portion with the slots 32. Besides enabling the above features, this extension also allows an adequate level of decoupling between the low band and the E-band.
The support 4 is a structure suitable for supporting the reflector 2 and the feed or receiver 3.
It may consist of a square, rounded or other casing, as long as it allows the device 1 to be constrained above a support structure 5. Therefore, the support structure 5 is, for example, a wall or a flat support surface.
Preferably, the support structure 5 consists of a well-known metal pole as usually found in the current state of the art.
In addition to the common support function, the support 4 comprises connections to at least one electrical apparatus 6 and internal components.
In particular, the components consist of a controller 40, at least a first connector 41 and a second connector 42.
The controller 40 is an electric element adapted to transmit electromagnetic signals at different frequencies.
It is therefore operatively an integral part of the feed 3.
Preferably, the controller 40 is a balanced power divider capable of supplying the second acquisition portion 31, i.e. the coaxial section of the dual-band feed 3, and, independently, of supplying the first acquisition portion 30, i.e. the E-band section. The first connector 41 is operatively connected to the controller 40 and the electrical apparatus 6.
Furthermore, the first connector 41 is adapted to transmit low-frequency electromagnetic signals. Therefore, the first connector 41 is preferably electronically or operatively connected to the second acquisition portion 31 via the controller 40. More in detail, the second acquisition portion 31 communicates with the first connector by means of the waveguides 34. These waveguides 34 preferably branch inside the controller as shown in Fig. 9.
Therefore, preferably, the controller 40 comprises one or more printed internal circuits defining transmission paths defined by the waveguides 34 or inside which they are included.
Low-frequency electromagnetic signals may be signals defining frequencies ranging from 10 to 40 GHz. More in detail, the first connector is designed to transmit signals at frequencies in the range 17.7-19.7 GHz or 21.2-23.6 GHz.
The first connector 41 appears as an opening compatible with a standard waveguide at the frequency to be transmitted, for example R220. However, this opening may be of a different shape that can be adapted to the specific interface of the radio equipment 6, depending on whether a single-polarization signal or a dual-polarization signal is to be transmitted.
If the device 1 is of the dual-polarization type, the device 1 preferably comprises two first connectors 41 adapted to transmit two signals with different polarity. A configuration of this type is for example shown in Fig. 4 and Fig. 6.
The second connector 42 is also operatively connected to the controller 40 and the electrical apparatus 6.
Furthermore, the second connector 42 is adapted to transmit high-frequency electromagnetic signals. Thus, the second connector 42 is electronically or operatively connected to the first acquisition portion 30 via the controller 40. More in detail, the first acquisition portion 30, and even more suitably the inner waveguide 35, pass through the controller 40 and are connected to the second connector 41.
High-frequency electromagnetic signals are preferably E-band signals and therefore define frequencies between 60 and 90 GHz. Most suitably, high-frequency electromagnetic signals are signals defining frequencies ranging, for example, from 71 to 76 GHz and from 81 to 86 GHz.
The second connector 42 appears as an opening compatible with a standard waveguide at the frequency to be transmitted, for example R740. However, this opening may be of a different shape that can be adapted to the specific interface of the radio equipment 6, depending on whether a single-polarization signal or a dual-polarization signal is to be transmitted, for example as previously described with regard to the configurations of the slots 32 and the related coupling receivers.
Furthermore, when the signal is a dual-polarization signal, the device 1 preferably comprises two first connectors 41.
The electrical apparatus 6 may consist of one or more electrical networks and may comprise other electrical devices suitable, for example, for processing the signals received or sent by the device 1.
Preferably, the electrical apparatus comprises at least two devices: a first radio 60 and a second radio 61.
Both radios 60, 61 are devices known in the state of the art.
They may be, for example, selected from a single-polarization, a dual-polarization and a dual-carrier radio as known in the current state of the art.
In particular, the radios 60, 61 are microwave devices produced by third parties and which are not part of the product object of this invention.
The first radio 60 is preferably connected to the first connector 41 and therefore is adapted to process low-frequency signals.
If the device 1 is of the dual-polarization type, it is preferably provided with two first connectors 41 and two first radios 60 respectively operatively connected to the corresponding first connector 41.
The second radio 61 is preferably connected to the second connector 42 and therefore is adapted to process high-frequency signals.
In the dual-polarization configuration, shown in Fig. 4, the device 1 preferably comprises three connectors, of which two are first connectors 41 and one is a second connector 40, respectively operatively connected to three radios and in particular to two first radios 60 and one second radio 61.
The operation of the telecommunications device 1, previously described in structural terms, is as follows.
The device picks up a signal via the reflector 2 and transmits it to the controller 40 via the feed 3.
The controller 40 then detects all the different-frequency signals and sends the low-frequency signals, specifically coming from the second acquisition portion 31, to the first connector 41, or first connectors 41, and the high-frequency ones, specifically coming from the first acquisition portion 30, to the second connector 42. Therefore, the device 1 harnesses an excellent transmission quality, but in case of bad weather allows reduced-band signals to be stored, thus allowing uninterrupted data transmission.
The telecommunications device 1 according to the invention achieves important advantages.
In fact, the device 1 allows electromagnetic signals to be sent and received over long ranges and in any weather conditions since, in case of failure of the system due to insufficiently robust E-band frequency signals, the information can be retrieved in parallel and directly reduced-frequency signals that are more robust.
This advantage is possible because the guide 31a allows, thanks to its shape, differently from the prior art, an increase in the scale factor between the guiding and radiating structures.
The above-described configuration allows mode conversions from TE10 of the rectangular guides to the hybrid HE11 mode of the coaxial guide, over wide bandwidths, with a very compact physical structure, good Return Loss performance and isolation between H and V polarizations.
In fact, it has surprisingly been found that the conical shape comprising the axially extending and radially arranged slots 32, as well as favouring the decoupling between the low and the high band, also favours the gradual transmission of the signals, resulting in an increase in the band that can actually be received.
From a numerical point of view, the bandwidths guaranteed by the prior art devices are much smaller than those achieved by the device according to the invention.
Therefore, the device 1 appears to have a simplified structure, as it corresponds to the classical single-antenna structure, and is advantageous in terms of overall dimensions. In fact, the shape of the guide 31a makes it possible to achieve very compact assemblies that are easy to install.
In conclusion, it is not necessary to resort to two antennas in parallel.
This advantage leads to the further advantage of reducing the costs that would otherwise be high due to the adoption of a plurality of antennas.
The invention is susceptible of variations falling within the scope of the inventive concept as defined by the claims. For example, the support 4, as well as the reflector 2, may be different from those shown in the figures.

Claims

A telecommunications device (1) configured to transmit and receive low-frequency and high-frequency electromagnetic signals and comprising:
- a reflector (2) defining an operating surface (20) configured to send and receive said electromagnetic signals,

- a feed (3) arranged in the proximity of said operating surface (20) and comprising a first hollow, cylindrical acquisition portion (30) and a second acquisition portion (31) coaxial with respect to said first acquisition portion (30) and configured to send and receive said electromagnetic signals at different frequencies,

- a support (4) constrained to a support structure (5) and connected to at least one electrical apparatus (6),

- said reflector (2) being constrained to said support (4) and configured to direct said electromagnetic signals from and towards said feed (3),

- said support (4) comprising
- a controller (40) operatively connected to said feed (3) and configured to transmit said electromagnetic signals at different frequencies,

- at least a first connector (41) operatively connected to said controller (40) and said electrical apparatus (6) and configured to transmit low-frequency electromagnetic signals coming from said second acquisition portion (31), and

- a second connector (42) operatively connected to said controller (40) and said electrical apparatus (6) and configured to transmit said high-frequency electromagnetic signals coming from said first acquisition portion (30),

wherein
- said first hollow, cylindrical acquisition portion (30) comprises an inner waveguide (35) consisting of the inner conductive layer of a coaxial cable.

- said second acquisition portion (31) comprises at least one guide (31a) in the shape of a truncated cone oriented so as to be converging from said reflector (2) to said support (4) and comprising a short-circuited portion (33) at the smaller base of said guide (31a),

- said guide (31a) including a plurality of slots (32) arranged along said guide (31a), each with a rectangular section extending axially along the side surface of said guide (31a) and each connected to waveguides (34), wherein said second acquisition portion (31) is configured to communicate with said first connector (41) by means of said waveguides (34),

- said low-frequency electromagnetic signals defining frequencies ranging from 10 to 40 GHz,

- said high-frequency electromagnetic signals being E-band signals and defining frequencies ranging from 60 to 90 GHz.
The device (1) according to claim 1, wherein said waveguides (34) are arranged perpendicular to the side surface of said guide (31a) and extend radially with respect to the axis of said second acquisition portion (31).
The device (1) according to at least one of the preceding claims, wherein said short-circuited portion (33) comprises a wall made of a conductive material and arranged at said smaller base of said guide (31a) around said first acquisition portion (30).
The device (1) according to at least one of the preceding claims, wherein said short-circuited portion (33) has a minimum reciprocal distance from each of said slots (32) of less than 5 mm.
The device (1) according to the preceding claim, wherein said short-circuited portion (33) has a minimum reciprocal distance from each of said slots (32) of less than 2 mm.
The device (1) according to at least one of the preceding claims, wherein said high-frequency electromagnetic signals define frequencies ranging from 71 to 76 GHz.
The device (1) according to at least one of the preceding claims, wherein said slots (32) are angularly evenly spaced along said truncated cone-shaped guide (31a).
The device (1) according to at least one of the preceding claims, wherein said slots (32) are four and connected two by two.
The device (1) according to at least one of claims 1-5, 7, 8, wherein said high-frequency electromagnetic signals define frequencies ranging from 81 to 86 GHz.
The device (1) according to at least one of the preceding claims, wherein said low-frequency electromagnetic signals define frequencies ranging from 17.7 to 18.7 GHz.
The device (1) according to at least one of claims 1-9, wherein said low-frequency electromagnetic signals define frequencies ranging from 21.2 to 23.6 GHz.
The device (1) according to at least one of the preceding claims, wherein said electrical apparatus (6) comprises at least a first radio (60) and a second radio (61) and said radios (60, 61) are selected from single-polarization, dual-polarization and dual-carrier radios.