RU2474936C1 - Device for receiving switched signal polarisation - Google Patents

Abstract

FIELD: radio engineering.

SUBSTANCE: invention can be used at basic stations of cellular radio communication network in order to provide signal emission with switched polarisation, and namely possibility of setting linear vertical polarisation, linear horizontal polarisation or circular polarisation of right or left rotation, when using stationary antennae of basic stations with cross polarisation, i.e. with double +45° and -45° inclined polarisation. Device includes in-phase equally amplitude power divider, two switched phase shifters having fixed values of entered phased progressions, which are equal to 0°, 90° and 180°, and three identical Y-circulators.

EFFECT: creation of the device allowing to receive switched polarisation of emitted signal when using stationary antennae used at basic stations of radio communication network, including multirange ones with cross polarisation.

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Description

FIELD OF THE INVENTION

The invention relates to radio engineering and can be used at base stations (BS) of a cellular radio communication network to provide radiation of a signal with switchable polarization, namely, the ability to set linear vertical polarization, linear horizontal polarization or circular polarization of right or left rotation, using standard antennas of base stations with cross-polarization, i.e. double + 45 ° and -45 ° inclined polarization.

BACKGROUND

Currently, cross-polarized antennas, i.e. dual + 45 ° and -45 ° inclined polarization, are widely used at cellular radio communication base stations to provide diversity reception.

Cross polarized antennas are, in contrast to vertical polarized antennas with a strictly vertical arrangement of emitters, a set of emitters symmetrically located along the vertical axis of the antenna and tilted to it at an angle of + 45 ° and -45 °. The symmetrical arrangement of the emitter systems relative to the axis of the antenna ensures symmetry and identity of the radiation path in the horizontal plane. It is very important that the vectors of the electric field emitted from the bottom of antennas with double + 45 ° and -45 ° inclined polarization are orthogonal to each other, and the required polarization isolation between the two antennas and the cross-polarization coefficient are stored in a given sector of azimuthal angles and provide conditions for effective diversity reception.

In the field of antenna technology, devices are known [1, 2], which are a system of XYZ rectangular coordinate systems inclined relative to the vertical Z axis by angles of + 45 ° and -45 ° emitters, which can be used to create two-channel weakly directional antennas used as linear elements phased array antenna, that is, a typical two-channel sector antenna of a base station of a cellular radio communication network with the same polarization characteristic. This ensures the formation of a beam pattern of a two-channel antenna with mutually orthogonal polarization of the radiation field (+ 45 ° and -45 °) in the channels and overlap of 3 dB in the horizontal plane of the beamforming sector with a width of about 90 ° and about 65 °, respectively, for devices described in [1] and [2]. The essence of the invention described in [1]: the antenna consists of two crosswise symmetrical vibrators placed above a metal screen mounted parallel to a flat screen at a height of not more than half the specified wavelength of the working frequency range, from it in the form of a flat cross-shaped conductor, consisting of four the same and orthogonal to each other quarter-wave shoulders. The technical result is to ensure the formation of a radiation pattern of a two-channel antenna with mutually orthogonal polarization of the radiation field in the channels, overlapping at a level of 3 dB sector width in the horizontal plane of about 90 °. The invention described in [2] differs mainly from the invention described in [1] in that instead of two crosswise symmetrical vibrators, a diamond-shaped arrangement of vibrators is used, which leads to an expansion of the aperture and, as a result, to narrowing the antenna pattern in horizontal plane to a width of about 65 ° at a level of 3 dB.

The use of antennas of these types leads to the fact that the polarization vector of the radiated antenna signal has a slope of + 45 ° or -45 °. In the case where the frequency range is allocated for the operation of the RES of a cellular radio communication network on a secondary basis, BS networks can create unintended radio interference of an unacceptable level to electronic devices operating in this frequency range on a primary basis. So, for example, GSM, GMT-2000 / UMTS, LTE, etc. BS operating in the 900 MHz band can cause unintentional interference with an unacceptable level of airborne radio navigation and landing RES using antennas with horizontal polarization. In this case, the polarization isolation between the signal emitted by the BS, equipped with standard cross-polarized antennas and the receiving antenna of the radio-navigation aerial navigation and landing is about 3 dB. This leads either to limiting the maximum permissible transmitter power of such BSs, or to achieve maximum polarization isolation, forcing cellular network operators to use sophisticated antenna systems with linear vertical polarization of the emitted signal and spatial diversity of the receiving antennas.

The problems of electromagnetic compatibility described above, which also relate to other frequency ranges in which cellular communication RES are operating, can also arise in relation to interference receptor RES, which have not only horizontal, but also vertical and circular polarization of both right and left rotation.

Also, in the case of using cross-polarized antennas, there is a problem associated with the emission of a BS transmitter signal with linear + 45 ° or -45 ° inclined polarization, namely, that an undirected linearly polarized antenna installed on a subscriber terminal has a weakened BS received signal due to polarization isolation, which is statistically more than 5 dB for 38% of the possible positions of the subscriber terminal, more than 10 dB for 21% and more than 15 dB for 12%. This problem can be solved by using circular polarization for transmission on a cellular communication station and maintaining double + 45 ° and -45 ° inclined polarization for reception.

The closest to the claimed technical solution is a device for forming the polarization of the radio signals of the transceivers [3].

The disadvantages of such a device, first of all, are large transmission losses (the declared value is ~ 3.6 dB) due to the use of a hybrid bridge having losses of more than 3 dB.

It should be noted that at present, base stations of cellular radio communications most often use transceiver equipment, including external transceiver radio modules installed in the immediate vicinity of BS antennas, in which the transmitter signal is supplied to only one of the arms of the cross-polarized antenna, and the signal the receiver is also removed from both shoulders. That is, in this configuration, only one of the outputs of the base station is transceiver, and the second is only receiving.

Moreover, the known device for generating the polarization of the radio signals of the transceivers even in the configuration of one transceiver output introduces attenuation along the transmission path of more than 3 dB.

The technical result, the achievement of which the present invention is directed, is to create a device that allows using standard antennas used at base stations of the radio communication network, including multi-band, with cross-polarization, that is, double + 45 ° and -45 ° inclined polarization , obtain a switchable polarization of the radiation of the signal, namely, either linear vertical polarization, or linear horizontal polarization, or circular polarization of the right or left rotation, and save the double + 45 ° and -45 ° tilt polarization at reception. A device connected directly to the antenna of the base station by means of phased radio-frequency connecting cables, which allows to reduce transmission losses, which would be ergonomic, not difficult to operate, economical.

SUMMARY OF THE INVENTION

The basis of the present invention is the creation of a device for obtaining a switchable polarization of the signal, which, by adapting to the modern principle of constructing a transceiver radio path of base stations of a cellular radio communication network, allows to reduce transmission losses, to provide the possibility of forming an arbitrary type of polarization for radiation and to maintain cross-polarization for reception , and, thus, improve technical, operational and functional characteristics.

The technical result is achieved by the fact that a device is proposed for producing a switched polarization of the emitted signal, connected directly to the base station antenna by phased RF cables, characterized in that it contains an in-phase equal-amplitude power divider, two switched phase shifters having fixed introduced phase raids equal to 0 ° , 90 ° and 180 °, and three identical Y-circulators of the forward direction, in which the minimum attenuation of the radio frequency signal with corresponds to the direction from the first input to the second, from the second to the third and from the third to the first, and the maximum insertion loss corresponds to the opposite direction, while these components are connected to each other by radio frequency transmission lines so that the input of the device to obtain a switchable polarization of the signal connected to the transceiver output of the base station is the first output of the second Y-circulator, the second output of which is connected to the input of the in-phase equal-amplitude divider, the outputs to torogo connected via switchable phase shifters to the first inputs of the first and third Y-circulator, exits the second device which are output to obtain a signal switchable polarization orthogonal to the plug inputs of the antenna cross-polarization, i.e. double + 45 ° and -45 ° slant polarization.

Possible additional embodiments of the device, in which:

- it is possible to use Y-circulators of the inverse direction;

- it is possible to use the components of the device, namely Y-circulators, a divider and phase shifters with an extended working band to implement a device that is applicable for several frequency ranges simultaneously.

Figure 1 presents a functional diagram of a device for obtaining switchable polarization of the signal.

Figure 2 presents the switching circuit of the device for receiving switchable polarization of the signal into the radio frequency path of the base station of a cellular radio communication.

The proposed device to obtain a switchable polarization of the signal 16 is connected by feeders 17 and 18 to the transceiver 19 and the receiving 20 inputs of the transceiver radio block sector of the base station 21 through the outputs 3 and 4, respectively (figure 2), and phased radio-frequency connecting cables 14 and 15 to the orthogonal antenna inputs with double + 45 ° and -45 ° inclined polarization 11 through inputs 1 and 2.

The proposed device for obtaining switchable polarization of the signal (Fig. 1) includes: a common-mode equal-amplitude power divider 10, two switchable phase shifters 8 and 9, with fixed values of the introduced phase incursions equal to 0 °, 90 ° and 180 °, and three identical Y -circulators 5, 6 and 7 of the forward direction, interconnected by radio frequency transmission lines so that the received signal from the output of the antenna with + 45 ° inclined polarization goes to input 1, after which, passing the first Y-circulator 5 with minimal losses, goes to the third input (BH) of the second Y-circulator 6, passing through which with minimal losses, goes to output 3, connected to the transceiver output 19 by feeder 17, while the received signal from the output of the antenna with -45 ° inclined polarization goes to input 2, after which, passing with a minimum loss, the third Y-circulator 7 is fed to output 4 connected to the input input 20 by the feeder 18. Thus, the signal paths received by the orthogonal inclined polarizations of the antenna of the base station 11 do not intersect and do not overlap It is than saved double + 45 ° and -45 ° slant polarization of the received signal and provides effective diversity reception. The signal of the transmitter of the base station from the transceiver output 19, fed through the feeder 17 to input 3, passing with a minimum loss of the second Y-circulator 6, is fed to a power divider 10, from the outputs of which the in-phase and equal-amplitude portions of the signal through the switched phase shifters 8 and 9 are fed to the first the inputs (A1 and C1) of the first and third Y-circulators 5 and 7, respectively, passing through them with minimal losses, go to outputs 1 and 2, connected to the orthogonal inputs of the antenna 11 with double + 45 ° and -45 ° inclined polarization. Thus, with equal-amplitude and in-phase excitation of orthogonal vibrators 12 and 13 of an antenna with cross-polarization, that is, double + 45 ° and -45 ° oblique polarization, the emitted signal will have a total vertical polarization vector, when installed using switchable phase shifters 8 and 9 the phase difference equal to -90 ° and + 90 °, the total emitted signal will have a left circular and right circular polarization, respectively, and when using the switchable phase shifters 8 and 9, the phase difference is + 180 °, the total emitted s drove will have horizontal polarization.

BRIEF DESCRIPTION OF THE DRAWINGS

The Figure 1 presents a functional diagram of a device for obtaining switchable polarization of the signal.

The Figure 2 presents a diagram of the inclusion of the device to obtain a switchable polarization of the signal into the radio frequency path of the base station of a cellular radio communication.

DETAILED DESCRIPTION OF THE INVENTION

The device for producing a switchable polarization of a signal based on a standard cross-polarized base station antenna system shown in FIG. 1, it is connected to the transceiver output 19 through input 3 by a feeder 17, to the receiving input 20 through input 4 by a feeder 18 and phased RF cables 14 and 15 to the standard antenna of the base station 11 with dual + 45 ° and -45 ° inclined polarization through outputs 1 and 2, and includes: a common-mode equal-amplitude power divider 10, two switchable phase shifters 8 and 9, with fixed values of the introduced phase incursions equal to 0 °, 90 °, and 180 °, and three identical direct Y-circulators 5, 6, and 7 directions in which the minimum attenuation for the sake of the frequency signal corresponds to the direction from the first input to the second (from A1 to A2, from B1 to B2, from C1 to C2), from the second to the third (from A2 to A3, from B2 to B3, from C2 to C3) and from the third to the first (from A3 to A1, from B3 to B1, from C3 to C1), and the maximum insertion loss corresponds to the opposite direction. The switching circuit of the device for producing switchable polarization is shown in FIG. 2. The received signal from the output of the antenna with + 45 ° inclined polarization goes to input 1, after which, passing the first Y-circulator 5 with minimal losses, it goes to the third input (OI) of the second Y-circulator 6, passing through which with minimal losses, arrives at output 3, connected to the transceiver output 19 of the transceiver radio unit of the base station sector 21 by the feeder 17, while the received signal from the output of the antenna with -45 ° inclined polarization is fed to input 2, after which the third Y-circulator 7 passes with minimal losses, doing to the output 4, connected by the feeder 18 to the receiving input 20 of the transceiver radio block of the base station sector 21, so that the signal paths received by the orthogonal oblique polarizations of the base station antenna are not crossed and do not overlap, which keeps the double + 45 ° and -45 ° inclined polarization of the received signal and the diversity diversity is ensured. The signal of the transmitter of the base station coming from the transceiver output 19 of the transceiver radio block of the base station sector 21 through the feeder 17 to input 3, passing with a minimum loss of the second Y-circulator 6, is fed to the power divider 10, the outputs of which are in-phase and equal-amplitude signal fractions through switchable phase shifters 8 and 9 go to the first inputs (A1 and C1) of the first and third Y-circulators 5 and 7, respectively, passing through which with minimal losses, go to outputs 1 and 2, connected to the orthogonal inputs of the antenna with double + 45 ° and -45 ° inclined polarization 11. Thus, with equal-amplitude and common-mode excitation of orthogonal vibrators 12 and 13 of the antenna with cross-polarization, that is, double + 45 ° and -45 ° inclined polarization, the emitted signal will have a total vertical the polarization vector, when installing using the switched phase shifters 8 and 9, the phase difference is -90 ° and + 90 °, the total emitted signal will have left circular and right circular polarization, respectively, and when installed using the switched phase shifters 8 and 9 spacing If these phases are equal to + 180 °, the total emitted signal will have horizontal polarization.

Thus, the desired technical result is achieved, that is, a device is proposed that allows to obtain a switchable polarization of the emitted signal on the basis of the standard antenna 11 of the base station with cross-polarization, that is, double + 45 ° and -45 ° inclined polarization, as well as maintain double +45 ° and -45 ° oblique polarization at reception and ensure diversity diversity.

Moreover, due to the absence of the need to dissipate half the power of the emitted signal in a coordinated load, the proposed device provides attenuation of the transmitter signal significantly less than that of the closest analogue. So, the total loss of the transmitter signal in the closest analogue is ~ 3.6 dB. As shown by testing the layout of the claimed device, the signal loss of the transmitter is ~ 0.6 dB. The total losses were estimated as the ratio of the sum of the power of the radio signals at the inputs of the cross-polarized antenna to the transmitter power supplied from the transceiver output of the base station. The loss of the receiver signal in the claimed device for both paths is ~ 0.6 dB.

The use of a Y-circulator for separation of the receiving and transmitting signals of the base station, the electrical parameters of which are stored in the entire working frequency band, provides the functionality of the proposed device for obtaining switchable signal polarization even for communication standards with a single frequency band for the receiver and transmitter, that is, with time duplex . Also, in the case of using elements of the proposed device, namely Y-circulators, a divider and phase shifters, with an extended working frequency band, it is possible to implement a device for obtaining switchable signal polarization, applicable simultaneously for several frequency ranges. The device is ergonomic, industrially applicable, convenient to use, does not require significant material costs and can be used repeatedly.

INDUSTRIAL APPLICABILITY

The invention relates to radio engineering and can be used at base stations of cellular radio communications. For example, on GSM, IMT-2000 / UMTS, LTE, and other BS standards for the possibility of obtaining maximum polarization isolation and ensuring EMC conditions, or for improving the quality of communication when using standard, including multi-band, base station antennas with cross- polarization, that is, double + 45 ° and -45 ° inclined polarization, the proposed device allows you to receive either linear vertical polarization, or linear horizontal polarization, or circular polarization of the right or left rotation, and save double + 45 ° and -45 ° oblique polarization of the received signal. The device is ergonomic, industrially applicable, convenient to use, does not require significant material costs and can be used repeatedly.

INFORMATION SOURCES

1. (PCT / EP98 / 03129) ANTENNA SYSTEM, Publ. 05/30/97.

2. (WO / 2002/050945) ANTENNA, IN PARTICULAR MOBILE RADIO ANTENNA, Publ. 06/27/2002.

3. (RU 2296398 C1) DEVICE FOR FORMING POLARIZATION OF RADIO SIGNALS OF RECEIVERS, Publ. 03/27/2007.

Claims (1)

A device for obtaining a switchable polarization of the signal, connected to the transceiver and receiver feeders of the base station sector and phased RF cables to the standard antenna of the base station sector of a cellular radio network with cross polarization, i.e. dual + 45 ° and -45 ° inclined polarization, characterized in which includes an in-phase equal-amplitude power divider, two switchable phase shifters having fixed values of introduced phase incursions equal to 0 °, 90 ° and 180 °, and three identically Y-circulator, in which the minimum attenuation of the radio frequency signal corresponds to the direction from the first input to the second, from the second to the third and from the third to the first, and the maximum attenuation attaches to the opposite direction, while these components are connected to each other by radio frequency transmission lines in such a way that the input of the device for receiving switchable polarization of the signal connected to the transceiver feeder of the base station sector is the first output of the second Y-circulator, W The second output of which is connected to the input of an in-phase equal-amplitude divider, the outputs of which are connected via switched phase shifters to the first inputs of the first and third Y-circulators, the second outputs of which are outputs of the device for receiving switchable polarization of the signal, connected to orthogonal inputs of the antenna with cross polarization, i.e. double + 45 ° and -45 ° inclined polarization, namely: phased RF cables to the standard antenna of the base station with a double + 45 ° and -45 ° inclined field This means that the third outputs of the first and second Y-circulators are interconnected, and the third output of the third Y-circulator is the output of the device for receiving switchable polarization of the signal, connected to the receiving feeder of the base station sector, which provides equal-amplitude division of the signal of the transmitter of the base station, equal to whose parts with minimal attenuation enter the device outputs connected by phased RF cables to the antenna inputs with a double + 45 ° and -45 ° inclined field If, by means of the installation of orthogonal vibrators of the orthogonal vibrators using dual-phase shifters, the antennas with double + 45 ° and -45 ° oblique polarization produce the total vertical polarization vector of the emitted signal, when the phase difference is equal to -90 ° and + 90 ° using the switched phase shifters , gives the left circular and right circular polarization of the emitted signal, respectively, and when installed using switchable phase shifters the phase difference equal to + 180 °, gives horizontal polarization of the emitted signal, this also ensures that the paths of the signal paths received by the orthogonal oblique polarizations of the base station antenna are eliminated, thereby preserving the double + 45 ° and -45 ° oblique polarization of the received signal and the diversity efficiency is ensured.

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