FI90927C - Satellite Antenna device - Google Patents

Description

i 90927

SATELLIITTIANTENNIJARJESTELY

The invention relates to a satellite antenna arrangement 5 as defined in the preamble of claim 1, in particular for a mobile earth station for voice communication.

New satellite systems are being developed, especially for mobile terrestrial communications systems. Communication and positioning systems such as Inmarsat 10 C, PRODAT, Euteltracks and Lockstar have already been introduced and are gradually being introduced. Marketing research also shows that there is a need for voice communication systems. Two systems, EMS (European Mobile System) and Inmarsat M, are being developed for mobile ground station communication systems for L-band voice-15 communications. The systems will complement the services provided, in particular, to terrestrial mobile stations by providing flexible closed networks covering the whole of Europe. One of the most promising applications is the truck communication network and.

Surround antennas can be used at low data rates. The gain of these antennas is of the order of 3 ... 5 dBi, which is usually sufficient. However, sound communication requires a better signal-to-noise ratio than can be provided by omnidirectional antennas. This requirement means that the antenna gain must be at least in the order of 10 ... 12 dBi. Many antennas are previously known, in which the antenna element is directional. Such antennas include e.g. certain slit and horn antennas and dipole antennas. The problem with these antenna units is the complexity and unsuitability of the feeder circuit adapters for monitoring systems. In addition, the mechanical properties of these antenna elements are often unsuitable specifically for a mobile ground station.

2

The object of the invention is to provide a new antenna arrangement by means of which the above-mentioned problems can be eliminated. It is a further object of the invention to provide an antenna arrangement which is inexpensive to manufacture and suitable for mass production.

The antenna arrangement according to the invention is characterized by what is stated in claim 1.

According to the invention, the satellite antenna arrangement-10 for a mobile earth station, in particular for voice communication, comprises an antenna unit which can be directed to the satellite in the azimuth plane. According to the invention, the antenna unit comprises two antenna elements and a ground plate, which elements are formed of a circular arc-shaped planar conductive microstrip and terminated in a load, which antenna elements are rotated 180 ° apart and arranged spaced apart. at a constant distance from the ground plane and by means of which the antenna unit 20 receives and transmits circularly polarized electromagnetic rain. The shape and dimensions of the ground plate as well as the distance of the antenna elements from each other and from the ground plate are optimized with respect to the maximum antenna gain and the minimum size of the ground plate.

25 In one application of the satellite antenna arrangement, the ground plate is formed as a pool-like part, inside which the antenna elements are mounted. Such a ground plate has a rigid mechanical structure. In addition, such a ground plate has a stabilizing effect on the impedance of 30 feed points.

In one embodiment of the satellite antenna system, the antenna unit includes a power distribution and phasing unit with two phasers and a 180 ° hybrid.

35 In one application of the satellite antenna arrangement, the power distribution and phasing unit is mounted on the back of the ground plate together with the loads of the antenna elements 90927 3.

In one embodiment of the satellite antenna arrangement, each phaser is a load line type phaser comprising two parallel transmission lines connected at the other 5 input and output ports and their transmission lines arranged between the input and output ports, and input and output ports adapted to the output and output ports. met to realize the phase difference · Three 10 beam beams in different directions can be implemented on the antenna unit by means of reflectors depending on the states of the switches of the phasers.

In one embodiment of the satellite antenna arrangement, it comprises a first body part in which the antenna unit 15 is mounted and support means by means of which the antenna unit is connected to the first body part at a suitable elevation angle with respect to the azimuth plane.

In one application of the satellite antenna arrangement, the support members are adjustable members for adjusting the elevation angle. By means of the support members, the elevation angle of the antenna unit is set in the azimuth plane so that the beam of the antenna is directed towards the satellite. The elevation angle varies between 10 ° and 50 ° and can be advantageously set at e.g. 10 ° intervals.

25 In one embodiment of the satellite antenna arrangement, it comprises a second body part and a rotary motor / and the first body part is movably mounted on the second body part so that the first body part and the antenna unit are rotatably fixed on the rotary motor of the second body. part. The fixed body of the tannel can be attached to a suitable base, such as a vehicle.

In one application of the satellite antenna system, the reversing motor is a stepper motor. The stepper motor-35 can be used to avoid adapting the gear unit to the reversing motor.

In one embodiment of the satellite antenna arrangement, it comprises a directing device comprising a control unit for performing satellite search and tracking, a detector and a measuring unit for measuring the rf level, means for determining the angular position of the antenna unit in the azimuth plane. When starting the antenna array with the aid of the aiming device, the satellite is searched by measuring the strength of the radio frequency signal in different directions and thus determining the direction to which the antenna unit is directed. Thus, a connection is established between the ground station and the satellite, and as the ground station moves, care is taken that the antenna unit is always directed to the satellite. With the help of suitable sensors, the orientation angle of the antenna unit is monitored in the azimuth plane and the rotary motor controller in turn controls the main motor so that the satellite is found first and the antenna unit remains oriented towards the satellite.

In one embodiment of the satellite antenna arrangement, it includes a flexible connection cable with which the 20 antenna units are connected to the directing device and the transceiver, and a limit switch for limiting the rotation angle of the antenna unit. By means of the limit switch, the antenna unit can be rotated in one direction by a maximum of 360 ° and thus the flexible cable does not have to rotate in one direction more than 25 revolutions and the mechanical stress on the cable does not become too great.

In one application of the satellite antenna arrangement, the antenna arrangement is covered with a shield. In this way, the antenna unit is protected from, for example, drift-30 in vehicle use and other possible environmental variations.

An advantage of the invention is that the antenna unit is a simple unit suitable for a relatively small space, which is inexpensive to manufacture and thus suitable for mass production.

A further advantage of the invention is that the antenna unit provides a reasonable gain of 90927 5.

A further advantage of the invention is that the antenna unit provides a suitable radiation pattern with a wide coverage area. The satellite antenna system is suitable for small elevation angles up to approx. 10 °, which are particularly important at northern latitudes for the use of the antenna system.

The achievement of a small elevation angle is particularly affected by the ground plane of the antenna unit.

Further advantages of the invention can be seen. The satellite search routines operate quickly when the antenna array is started. Furthermore, the antenna arrangement takes into account a reasonably large antenna unit alignment error, taking into account the bandwidth and gain of 15 antenna units. A further advantage of the arrangement is that it operates with a low signal-to-noise ratio. Furthermore, the antenna arrangement operates reliably despite short- and long-term changes in the signal level. A further advantage of the antenna arrangement 20 is that it recovers quickly from interference situations. In addition, the antenna arrangement causes minimal distortion to the communication channels. For example, switching between different radiation beams of an antenna unit causes a difference in amplitude or phase of the rf signal of at most ± 0.5 25 dB and ± 10 °, respectively.

The advantage of the invention is generally found to be that it works well and reliably in a very demanding environment of radio frequency radiation propagation.

In the following, the invention will be described in detail with reference to the accompanying drawings, in which Figure 1 is a plan view of a satellite antenna arrangement according to the invention; Figure 2 shows a cross-section A-A of the satellite antenna arrangement of Figure 1; Fig. 3a is a top view of the antenna unit and Fig. 3b is a side view; Figure 4 is a block diagram of the main parts of a satellite antenna arrangement according to the invention; Figure 5 schematically shows a hybrid; Figure 6 schematically shows a phaser; Figure 7 shows a layout diagram of the power distribution and phasing unit 5; Figure 8 shows the radiation beams of the antenna unit; and Figure 9 shows the alignment device in block diagram form.

Figures 1 and 2 show a satellite antenna arrangement according to the invention in an illustrative schematic view. The antenna arrangement comprises an antenna unit 1 and a power distribution and phasing unit 2. Further, the satellite antenna arrangement comprises a first body part 3 and a second body part 4. The antenna unit 1 is mounted on a support of the first body part 3. The antenna-15 arrangement also includes support members 5 by means of which the antenna unit 1 is arranged in the first body part 3 at a suitable elevation angle α with respect to the azimuth level B to B. The support members 5 are e.g. support rods of a periodic or continuous length an actuator-adjustable member for adjusting the elevation angle α.

In the arrangement of the satellite antenna, the first body part 3 is movably mounted in connection with the second body part 4. This is realized in such a way that the first body part 25 is mounted from the pivot shaft 6 to the second body part 4. In this case, the first body part with the antenna units 1 can be rotated with respect to the axis C - C in the azimuth plane B - B. by means of a stepper motor 7 30 adapted to the connection.

The antenna unit 1 of the satellite antenna arrangement is directed to the satellite by means of a special directing device 8. Such a directing device comprises at least a control unit 33 for performing satellite search and tracking, means for determining the angular position β of the antenna unit in the azimuth level B - B, a stepper motor controller 39 and means for transmitting the received radio frequency 90927 7 rainfall will be described in more detail later.

The means for determining the angular position måå-5 of the antenna unit in this application include a position sensor 9 / such as a Hall sensor connected to the first 3 and the second body part 4. The position of the body parts relative to each other in the rotational plane B - B and the angular position of the antenna unit 1 β with respect to a predetermined fixed circumferential point 10, e.g., D, can then be determined using the rotational position information of the stepper motor 7 and the stepper motor position calibration information obtained from the position sensor 9.

The satellite antenna arrangement further comprises a flexible connection cable 11 and a limit switch 12. By means of the connection M cable 11, the antenna unit 1 is connected to a directing device 8 and a transceiver (not shown in the drawing). By means of the limit switch 12, the rotation angle β of the antenna unit 1 is limited so that the first body part 3 of the antenna unit 1 cannot be turned in one direction from the switch but by a maximum of 360 °, i.e. by one revolution.

It is advantageous to combine the limit switch 12 and the position sensor 9 into a single switch, by means of which the angular position β of the stepper motor 7 is checked and the rotation of the stepper motor 7 and the first body part 3 to 360 ° is limited.

The antenna arrangement is furthermore covered by a protective cover 13. It is preferably attached to the second part 4 of the frame 30. Within the protective cover 13, the frame part 3 with its antenna units 1 is located in a sheltered environment.

The antenna unit 1 of the satellite antenna arrangement is shown schematically in Figures 3a and 3b. The antenna unit 1 comprises two antenna elements S 14, 15, which 35 are similar in structure. The antenna elements 14, 15 are arranged at a distance from each other. They are attached to the proximity of the ground plate 16 in this direction 8 a short distance from it. The antenna elements 14, 15 are turned at an angle of 180 ° to each other.

The antenna elements 14, 15 are drift-type air-insulating antenna elements. The antenna element 14, 5 15 is formed of a thin planar strip 17 of a curved thin conductive material, such as copper. The strip is mounted on an insulating material board, e.g. utilizing known circuit board technology. The strip has a standard plate and is substantially in the shape of an arc of a circle 10 which fills a sector of 270 °. The nominal electrical length of the antenna element 14, 15 is close to the wavelength used. The strip 17 is arranged at a constant distance from the ground plate 16. At each end of the strip 17 there are triangular strip parts 171 and poles 18, 19. One pole 15 acts as an input pole and the other as a load pole. The antenna element 14, 15 is symmetrical. Depending on the direction of circular polarization used, both poles 18, 19 can act as either input or load poles.

The beam power 20 of the antenna element 14, 15 can be adjusted by adjusting the width b of the microstrip 17 and the distance h from the ground plate 16. Optimal antenna gain is achieved when about 90% of the power supplied to the antenna is converted into radiation and 10% is absorbed into the matching load.

An antenna unit 1 with two antenna elements 1 achieves significant advantages over one antenna element. It has been found that the optimal gain values of the antenna element and the widths of the radiation beam depend on the slit and size of the ground plate. The maximum direction of the main beam depends somewhat on the frequency used and deviates from the normal of the ground plate by about 5 to 15 °. This deflection angle also depends on the shape of the ground plate. By means of two cooperating antenna elements 14, 15, which elements are rotated 180 ° to each other and arranged at a distance 35a from each other in the vicinity of the ground plate 16 and which are fed in parallel with a suitable phase difference27, the angular dependence of the main radiation beam 90 can be adjusted. Thus, the fitting of the antenna elements 14/15 to the ground plate 16 at the other end reduces the inclination of the radiation beam, in particular with respect to the frequency used. The ground joints and the shape of the ground plate 5 as well as the distance a and the distance between the antenna elements 14, 15 from each other and from the ground plate can be optimized so that the maximum antenna gain is achieved with the smallest possible ground plate size.

It should be noted that when using two antenna-10 drain elements 14, 15, the ground plate 16 el must not necessarily be a straight plane, but must be at an angle of up to e.g. 20 ° to each other without any serious changes in the rainfall distribution, such as overhangs. , Hawaiian-15. Thus, the antenna elements 14, 15 with the ground plate 16 can be folded at a small angle to each other.

The ground plate 16 is a rectangular plane, the edges 16a, 16b, 16c and 16d of which are turned upwards 20 so that the ground plate forms a shallow basin. The width 1 of the ground plate 16 is of the order of the distance a of the antenna elements 14, 15 and the length k of the ground plate is in turn of the order of 1.7 to 2x x. The depth s of the subterranean ground plate is in the order of 0.1a. In one preferred embodiment, the dimensions of the ground plate 16 are 325 x 175 mm 2 and the depth of the ground plate is 20 mm. The ground plate is made of a suitable conductive material, such as aluminum. The ground plate 16 of the underwater two antenna units has the advantage, in addition to the above, that it increases the antenna gain and stabilizes the shape of the main beam, in particular at different elevation angles.

A conductive strip 10 is arranged in connection with the ground plate 16 in the vicinity of the poles 18, 19 of each antenna element 14, 15; 10a, 10b. This strip is substantially straight and extends in the direction of the edges of the triangular strip portions 171 approximately to the width of the microstrip 17, as can be seen in Figure 3a. Nåmå strips 10; 10a, 10b improve the transmission characteristics of the rf signal and stabilize the matched input circuit to the antenna elements.

Figure 4 shows a block diagram of a satellite antenna arrangement according to the invention. The syphite terminals 18 of the antenna elements 14, 15 of the antenna unit 1; 18a, 18b are connected to the power distribution and phasing unit 2 and the second poles 19, respectively; 19a, 19b to fit loads 20; 20a, 20b. The power distribution and phasing unit 2 comprises two two phasers, i.e. the first phaser 21 and the second phaser 22, secS 180 ° hybrid 23. The first input 23a of the hybrid 23 is the input of the power distribution and phasing unit 2 and is connected by a flexible cable 24 to the directing device 8 secS receiver-transmitter unit 15 (not shown in the drawing). One of the inputs of the hybrid 23 is connected to the ground via the load 25. The wires 23c, 23d of the hybrid 23 are connected to the input of the first phaser 21 and the input of the second phaser 22, respectively.

The hybrid 23 is shown schematically in Figure 5. The input and output ports are denoted by the same reference numerals as in Figure 3. The input port 23a is a differential or D port and the input port 23b is a sum or S port. When the signal is input from the D-port, the output ports receive output signals that are 180 ° out of phase with each other. While a hybrid signal is input from the S-port, signals from the same phase are output from the output ports.

The phasers 21, 22 are implemented by means of transmission lines 30 and switching elements, as shown in Fig. 6 kSy. The stage 21, 22 comprises two parallel transmission lines 26a, 26b and 27a, 27b connected at one end to the input and output ports P1, P2, as well as transmission lines 28a, 28b connected between the ports.

In addition, the phase shifter 21, 22 comprises switching elements 31 and 32 arranged in each of the ports PI, P2 at the locations of the adapter lines 29a, 29b. The switching elements 31, 32 are 90927 11 implemented by means of suitable diodes and can be connected to a conductive state or a closed state. Both coupling members 31, 32 are simultaneously in the same state, whereby the phasing 21, 22 is symmetrical in structure.

5 Transmission characteristics of phaser 21, 22 from port PI

to port P2 or vice versa are thus the same. The hSvices of such a load line type phaser 21, 22 are small and the frequency range is wide. In addition, the matching properties of the phaser are good.

A preferred embodiment of the power distribution and phasing unit 2 is shown as a layout diagram in Figure 7. The hybrid 23 and the phasers 21, 22 are made on the same substrate by the microstrip method. The loads 20a, 20b of the antenna unit 1 are also integrated on the same substrate. The power distribution and phasing units 2 are preferably located behind the antenna unit 1 and connected by transmission lines to the input terminals 18a, 18b of the antenna elements 14, 15. The ground terminal is connected to the ground plate 16. The power distribution and phasing unit 2 then has only one input / output port 23a on which a suitable connector, such as an SMA connector, is mounted. The directing device 8 is connected by a flexible cable 24 (cf. Fig. 3) to the connector of any power distribution and phasing unit 2.

The phasers 21, 22 are optimized in this application to provide a phase shift of 23 °. This means a separation angle of about 8 ° (± 4 ° from the straight direction) for the radiation beams available from the antenna unit 1. With a larger phase shift, a larger separation angle is achieved. This means that by changing the states of the phase shifters 21, 22 and in particular their switching elements 31, 32, the direction of the rain beam of the antenna unit 1 can be changed between the central position and these SS positions, as will be shown below.

In the orientation of the antenna unit 1 by means of the control unit 35 8, phasing devices 21, 22 are used to orient the radiation beam when implementing satellite tracking. By appropriately controlling the switches 31, 32 of the stage 21, 22, it is possible to switch from the right beam "Right" to the left beam "Left" or the center beam beam "Mid", as illustrated in Fig. 8. The width of the radiation beams is somewhat affected by the elevation angle α and also the reception and transmission bands used. The above power distribution and phasing unit 2 is at most intended for the frequency range 1.5 to 1.7 GHz.

The connection from the right rain beam "Right" 10 to the left rain beam "Left" or vice versa is carried out in such a way that the state of the coupling members 31, 32 of both phasing stops 21, 22 is changed. In this case, the reflectors change into mirror images of each other. Correspondingly, if only the state of the second switching element 15 31 or 32 is changed, the radiation beam moves from the center radiation beam "Mid" to either the right "Right" or the left "Left" radiation beam.

Figure 9 shows in block diagram form the directing device 8 and the units and devices of the antenna arrangement 20 connected thereto. The directing device comprises a control unit 33 and a detector and measuring unit 34. The control unit 33 is preferably formed of a data processing unit 33a and a memory unit 33b connected to it. Also connected to the control unit 33 are a plurality of connection units 25, such as an angle detector connection unit 35, an elevation angle sensor connection unit 36, an A / D converter 37 for transferring the measured rf level from the detector and measurement unit 38 to the control unit 33, and a support member controller 40. The orientation unit 8 further includes interface units for inputting data such as programs and other information of the control unit 33 to the orientation device 8 and an interface unit 43 for connecting the orientation device 8 to external systems. In addition, the directing device may include a compass connection unit 41 for connecting an electronic compass unit 47 to the directing device.

90927 13

The angle detector connection unit 35 is connected to a limit switch 12 or alternatively to an angle sensor 9 for determining the angle position of the antenna unit 1 in the azimuth plane. The socket 36 of the connection angle detector connection 5 is in turn connected to the elevation angle detector 45, which is arranged between the first body part 3 and the antenna unit 1 (cf. Fig. 2). The detector and measuring unit 34 includes a select frequency section and an rf detector, as well as a measuring section for measuring the rf level. This 10 is fed via an A / D converter 37 to the directing device. The switching unit 38 is connected to the switching elements 31, 32, such as diodes, of the phase repeaters 21 and 22 of the power distribution and phasing unit 2. The stepper motor controller 39 is connected to the stepper motor 7. In this case, the support members 5 are provided with an actuator 46 (cf. Fig. 2), such as an electric motor, for lengthening and shortening the support members 5. The support member actuator 46 is connected to the support member controller 40.

By means of the orientation device 8, the search and monitoring of the satell-20 connector is carried out as follows. When starting the satellite antenna arrangement, the elevation angle a of the antenna unit 1 is checked. If the elevation angle α does not correspond to the position of the earth station in relation to the latitude and the satellite, it is corrected e.g. 10 ° at 10 ° -50 °. The shape and width of the rain beam are such that 10 ° gain steps are sufficient to achieve good antenna gain and signal-to-noise ratio. The elevation angle α is corrected by adjusting the length 30 of the support member 5 by means of the actuator 46 of the support members so that the desired elevation angle α is reached. The elevation angle α is obtained via the elevation angle viewer 45 to the orientation unit 8.

If the satellite antenna arrangement is used in a relatively small geographical area, the elevation angle α can be adjusted, for example, manually and kept at this value permanently.

After setting the elevation angle α, the antenna unit 14 is rotated on the first body portion 3 about an axis C to C by a stepper motor 7 in a predetermined direction, such as counterclockwise, until the limit switch and 12 are reached. Check the azimuth angle fl.

5 After that, the first or rough search program is started. The level of the satellite radio frequency signal, i.e. the rf level, is measured by the detector and measuring unit 34 at suitable angular intervals, such as at 18 ° intervals, whereby the 360 ° circular sector has a total of 20 measurement-10 points. The rf level measurements obtained from these measurement points are stored in the memory 33b. During this measurement, either the right or left radiation beam can be used (see Figure 8).

When the first series of measurements has been performed, the antenna unit 1 is rotated to the edge of the angular range in which the maximum rf level signal is measured. After this, another, precision search subroutine, is started. The angular sector of this search window is e.g. ± 27 ° and the measurements are performed with a denser angular separation of 20 than in the coarse measurement; eg at angular intervals of 9 ° or less. The measurements are performed in the above-mentioned area, after which the antenna unit 1 is turned to the point where the maximum rf signal level is detected. After that, we move on to the monitoring phase.

The monitoring phase is based on measuring the rf signal level with two different radiation beams, i.e. with the left and right radiation beams, as previously described in connection with the division and phasing unit. The measurement is in principle carried out first at the first beam such as the left beam ("Left") and then at the second beam such as the right beam ("Right") by changing the state of the switching elements 31, 32 of the phase shifters 21, 22 as previously described. From the measured differences in the rf level, it is calculated in the control unit 33 how many steps the stepper motor 7 has to take in a certain direction in order for the antenna unit 1 to be directed to the satellite with sufficient accuracy.

90927 15 In this way, the aim is to keep the antenna unit 1 continuously directed at the satellite target in order to maintain the telecommunication connection despite the ground station.

A digital compass unit 47 can be connected to the aiming device 8 and a other detector can be used to monitor the turning of the vehicle, and this can be used to effectively help keep the aiming unit pointed at the satellite.

The foregoing invention has been described, at most, with reference to one preferred embodiment thereof, but many modifications are possible while remaining within the scope of the invention as defined by the appended claims.

15

Claims (11)

16 A satellite antenna arrangement for a mobile earth station, in particular for voice communication, comprising an antenna unit (1), the antenna elements (14, 15) being travel-type air-insulating antenna elements, and which antenna unit can be directed to a satellite in an azimuth plane, known as 1) comprises 10 two antenna elements (14, 15) and a ground plate (16), which elements are formed by a circular arcuate planar conductive strip (17) and placed in a load (20, 20a, 20b), the antenna elements being angled 180 ° to each other and spaced 15 apart at a constant distance from the ground plane and having an antenna unit for receiving and transmitting circularly polarized electromagnetic rain. A satellite antenna arrangement according to claim 1, characterized in that the ground plate (16) is formed as a pool-like part, inside which the antenna elements (14, 15) are mounted. Satellite antenna arrangement according to claim 1 or 2, characterized in that the antenna arrangement comprises a power distribution and phasing unit (2) with two phasing (21, 22) and a 180 ° hybrid (23). Satellite antenna arrangement according to Claim 3, characterized in that the power distribution and phasing unit (2) is mounted on the rear side of the ground plate (16) together with the loads (20; 20a, 20b) of the antenna elements (14, 15). Satellite antenna arrangement according to Claim 3 or 4, characterized in that each phase shifter (21, 22) has two transmission lines (26a, 26b; 27a, 27b) connected in parallel at the other ends to the input and output ports (PI, P2). , 90927 17 transmission lines (28a, 28b) arranged between the input and output ports (PI, P2), and switching means (31) mounted at the ends of the matching lines (29, 29b; 30a, 30b) connected to the input and output ports (PI, P2). 32) to implement phase difference 5. Satellite antenna arrangement according to one of the preceding claims, characterized in that the satellite antenna arrangement comprises a first frame part (3) in which the antenna unit (1) is mounted and support members (5) by means of which the antenna unit (1) is arranged in the first frame (1). 3) at a suitable elevation angle (a) with respect to the azimuth level (BB). Satellite antenna arrangement according to Claim 6, characterized in that the support elements (5) are adjustable means for obtaining an elevation angle (α). Satellite antenna arrangement according to one of the preceding claims, characterized in that the satellite antenna arrangement comprises a second body part (4) and a rotary motor, preferably a stepper motor (7), and the first body part (13) is mounted on the second body part (13). 4) movably so that the first body part (3) and the antenna unit (1) are rotatable in the azimuth plane with respect to the second fixed body part (4) by a rotary motor. Satellite antenna arrangement according to claim 8, characterized in that the satellite antenna arrangement comprises a directing device (8) comprising a control unit (33), a detector and a measuring unit (34) for measuring the radio frequency signal level, means (9) for the antenna unit to determine the angular position in the azimuth plane and a rotary motor controller (39). Satellite antenna arrangement according to claim 7, characterized in that the antenna arrangement comprises a flexible connection cable (11) 18 with which the antenna unit (1) is connected to a directing device and a transceiver, and a limit switch (12) for the antenna unit rotation angle (β) limit. Satellite antenna arrangement according to one of the preceding claims 5, characterized in that the antenna arrangement is covered by a protective cover (13). 90927 19