DE1591610C - Rotary beacon sector, preferably for landing approaches - Google Patents

Description

1 .2

The invention relates to a sector directional radio beacon, in such a way that when the said line is arranged, for example, for the landing of aircraft .s perpendicular to the sector axis, the distance of the first would be advantageous. In practice, a sideband radiator has emerged from the main radiator according to the need for an approach radio beacon, which is suitable for the desired sector width and which is around the aforementioned net, if possible without addition or modification 5 times greater spacing of the second sideband with on-board reception systems for the route navigation system - to work together radiators according to the desired number of gation, for the large number of flight radiation sheets in the sector are chosen,
witnesses who are only equipped with such devices. In doing so, a coarse and fine measurement should be made use of the known principle, a moving azimuth formation in a small sector in which the interference field with hyperbolas is generated by approaching the runway. In that, in the simplest form, this task is spatially separated from two antennas as an on-board receiver, two by a small amount to the Tacan receivers for route navigation different frequencies (F, F + f) with a compound modu- be. As a result, a wandering hyperbolic field Iation, a coarse azimuth measurement with a 15 Hz frequency, is generated, the hyperbolas of which move with one of the difference components and a fine measurement with a 135 Hz frequency / corresponding speed. Component is performed; A receiver located in this interference field on the receiving side results from the fact that on the transmitting side, in addition to an amplitude modulation of the receiving cardioid, a rotating multi-leaf (9 leaf) wave whose phase is direction-dependent. A radiation pattern is sent out. · 20 radio beacons of this type that were tried and tested a long time ago

It is part of the task of the invention that the Funk-Art, which was called »Erika«, is with several

fire for landing in such a way that the antenna pairs have been carried out. Be there

now widely used by the individual pairs of antennas, different carriers

Tacan receiver without any changes also for gerfrequenzen (F), but the same sideband

the landing approach, but here with increased measuring 25 resp. ' Modulation frequency (f) broadcast, the

accuracy can be used; these work with separate receivers that phase difference

with a twofold phase comparison of the from the matched to the different carrier frequencies

Directional span derived from the modulation envelope, processed modulation frequencies (/)

voltages of 15 Hz and 135 Hz with corresponding azimuth results.

the reference signals transmitted by the radio beacon 30 To explain the type of application

to carry out a rough and fine measurement of the general principle just described

Azimuth. 'The approach light is initially assumed to be from

The special task at the transmitter side of the two dipoles at a distance of z. B. a wave

Airborne radio beacon therefore consists in broadcasting the same frequency as the Tacan radio length (X). There-

Fire-equivalent electromagnetic field in a 35 through creates a four-leaf radiation pattern

broadcast specific sector; the transmitter system with an opening angle of about 60 ° with a radiation

should be small and transportable, the antenna arrangement should be maximum perpendicular to the antenna plane with the same

without rotating parts. phase supply (Fig. 1) of the two dipoles resp.

The solution to this problem is, in principle, a with a minimum with out-of-phase feed

rotating interference field with coarse and fine direction 40 (Fig. 2). By phase shifting one or both of them

management components suggested, the one with purely electrical supply voltages can therefore use the entire diagram

fishing means is generated. can be relocated at will. With continuous phase

The special task of the invention is rotation or an increase in the frequency of the feed, a sector rotary radio beacon for cooperation tension ζ. B. the dipole 2 opposite the dipole 1 with (e.g. Tacan) receivers for the routes 45 the radiation leaves move clockwise; is to indicate navigation, in which an azimuth coarse the frequency of the dipole 2, for example, around 15 Hz measurement and fine measurement by phase comparison higher than that of dipole 1, then the whole thing rotates between from the rotating radiation field of the radio radiation diagram clockwise fifteen times fire derived, as components of a combined in the second, so that for an observer in the remote modulation envelope present coarse field within the sector 50 the received high frequency. or fine directional signals and the corresponding sequence has a 15 Hz amplitude modulation, Zugssignalen is made, preferably for their phase, just as with the usual rotary radio dcn Landing approach of airplanes. fire, is directional.

The invention is characterized by the As with all multi-sheet diagrams is also with Use of a known per se, from one with a 55 in this example - but at the expense of multi-carrier frequency fed main radiator and a clearness - a considerable measurement accuracy achieved in a fixed amount of several carrier wavelengths. Within that assumed here as an example Distance from this on a line passing approximately through the sector of ± 30 ° passing through the two zeros the main radiator goes, built up, with one in the diagram perpendicular to the dipole plane in Landecinem the speed of rotation of the hyperbolic direction arises, become 360 ° electrical degrees the amount of the carrier fre- within 60 degrees of azimuth, so that in sequence of different Scitenbandfrequency stored the selected example 1 azimuth degree 6 electrical Most Scitcnbandstrahler corresponds to existing Strahleranord- degrees.

In order to facilitate the scale reading, the sector width could be dimensioned so that, for example, the scan band frequency is fed and in a multiple greater distance that is 1 azimuth degree 10 electrical degrees of the on-board power supply correspond to the mentioned; that would result in ± 18 ° for the second side band radiator built up in width in the direction of loading. The dipole distance (d), which is

for this, rf = - · λ = 1.6λ; for a middle one

Frequency in the Tacan band (30 cm) results in about 50 cm. With a "gear ratio" of 1: 5 (1 degree of azimuth = 5 el. Degrees) the sector width is about 70 °, the dipole distance about 25 cm.

In order to make the approach radio beacon described here compatible with the Tacan system with regard to the receiver, it must be ensured that the modulation sidebands of 15 Hz and 135 Hz caused by the circumferential reflectors are emitted with 18% modulation each. Accordingly, the current ratio between the dipole radiating frequency F (1 in FIG. 3) and the dipole radiating frequency F + / (/ = 15 Hz) (2 in FIG. 3) must be selected to be 1: 0.18 . As in the normal Tacan system, the reference pulse groups are expediently emitted by the dipole (1 in FIGS. 3 and 4) fed with frequency F , so that the phase comparison in the on-board receiver can be carried out in the usual way.

The single sideband radiation can also be transmitted through a further dipole (3 in FIG. 4), which is a mirror image of the Dipole 2 - in relation to dipole 1 as a mirror plane - and with a frequency F - / (/ = 15Hz) is fed to a normal double sideband modulation to achieve that Radiation field has the characteristic of a pure amplitude modulation, which is known to be on the receiving side has a very favorable effect on the shape of the curve (distortion factor). This will be greatly diminished because of the Harmonic distortion can prove particularly useful if the radio beacon has a higher degree of modulation is desired, e.g. B. with VOR radio beacons.

The accuracy of this rough measurement would in itself be required for the approach of an aircraft (long-range approach as »Clearance«) to the runway is sufficient; the Tacan on-board receiver would, however, be missing 135 Hz modulation give an alarm. Therefore also the 135 Hz modulation for the on-board receiver to make available and also to enable a fine measurement, is the One-sheet diagram within the sector a 9-sheet diagram superimposed. This is achieved by having another dipole 4 '(Fig. 4) at a distance

9 λ (about 4.5 m) is arranged from the dipole 1, the

is fed with a frequency F + 9 / (F + 135 Hz). With the same amplitude ratio of the high-frequency energy to dipole 1 (main radiator) of 1: 0.18, a total of 9 radiation maxima and minima are created within the sector of ± 18.31 ° latitude (measured in azimuth degrees), which rotate at 135 Hz. The reference signals required for the phase measurement for the fine measurement, as well as those for the coarse measurement, are emitted by the radio beacon as modulation of the carrier, for example. The amplitude modulation resulting from the antenna arrangement and its special feed, which occurs in the .6 ° receiver, corresponds within the mentioned sector of 36 ° to the radiation of a normal Tacan transmitter system over 360 °; therefore there is a tenfold accuracy of measurement.

The antenna system of the ground station is a large base system with 15 λ dipole spacing and offers all known advantages with regard to multipath propagation (reflections) of the high-frequency waves; she therefore works cheaper than an omnidirectional Tacan antenna.

The dipole radiation is expediently bundled, e.g. emitted with horn radiators (see Fig. 4) with an opening angle of the radiation pattern of about 45 °, so that a lateral Radiation of high frequency energy prevented and thus an ambiguity of the receiving side Measurement is at least greatly reduced.

To. Ensure that the antenna system is mainly in a desired direction (to the front) and that the energy emitted in the opposite direction (to the rear) is as small as possible, the main radiator (1 in FIG. 4) is shifted forward by the value of a quarter wavelength, which Measure to achieve such an effect is known from other plants. This measure However, it can only be used with success if it is a double-sideband system, i. H., even if the radiator (3 in FIG. 4) is present and fed with the lower sideband (F - 15 Hz).

If now the transmitter for the supply of the main radiator (dipole 1) in a known manner as a receiver-transmitter combination (Transponder) is formed, the receiver of which distance query signals from Aircraft picks up, with which the transmitter is then modulated in a known manner, so the aircraft can also measure their distance from the beacon. If there is no query, the carrier is noise-modulated ("Constant duty cycle" method).

Assuming that the main transmitter (dipole 1) has a peak pulse energy of about 1 kW is required, the sideband transmitters need around 40 W peak pulse energy. Between the main transmitter and the sideband transmitters must now have a rigid phase relationship with regard to both the difference frequencies as well as the pulse train exist. The generation of separate However, carrier and sideband frequencies with such a phase relationship are known (German patent specification 1133 773).

Such an antenna arrangement is very good for mobile use as a landing and approach radio beacon suitable because there are no moving parts and therefore no energy requirement for rotating the antenna system necessary is.

Claims (6)

Patent claims: 1. Sector rotary radio beacon for cooperation with (e.g. Tacan) receivers for route navigation, in which an azimuth coarse measurement and fine measurement by phase comparison between coarse or Fine directional signals and corresponding reference signals is made, preferably for the landing approach of aircraft, characterized by the use of a known main radiator (1) fed with a carrier frequency (F) and a fixed, several carrier wavelengths spacing (d) therefrom a line that goes approximately through the main radiator, with a sideband frequency that differs from the carrier frequency in an amount that determines the rotational speed of the hyperbolic stand lines. I 591 • frequency (F + f) fed sideband radiator (2) existing radiator arrangement together with an analogous way with a multiple of the stated amount different sideband frequency (F + «/) fed and at a multiple greater than the S mentioned (nd) The second sideband radiator (4) constructed along the said line in such a way that, when the said line is arranged perpendicular to the sector axis, the distance of the first sideband radiator from the main radiator corresponding to the desired sector width and the spacing of the second sideband radiator which is greater by the stated multiple corresponds to the desired number of Radiation sheets in the sector are chosen. . is 2. Sector rotary radio beacon according to claim 1, characterized in that the sector width is two times 18 ° is chosen, and that the distance of the first Sideband radiator (2) from the main radiator (1) - · λ and that of the second sideband radiator (4) from the main radiator (1) 9 · - | - · λ . 3. Sector rotary radio beacon according to claim 1, characterized in that the carrier frequency (F) feeding the Hauptstrah- as ler (1) is modulated with the reference signals for the coarse and fine measurement. * 4. Sector rotary radio beacon according to claim 3, characterized in that for additional distance measurement the transmitter for feeding the main radiator (1) in a known manner with response signals to the distance query signals of the aircraft recorded by means of a receiver is modulated. 5. Sektof rotary radio beacon according to claim 1, characterized in that a further sideband radiator (3) in a mirror image of the first sideband radiator (2) with respect to the sector axis is provided with respect to the sector axis to generate a radiation field which has the characteristic of a pure amplitude modulation opposite sideband frequency (F - f) of the first sideband radiator is fed. 6. Sector rotary radio beacon according to claim 5, characterized in that for attenuating the Radiation of the antenna system in the opposite direction to the main direction of the main radiators (1) is offset by a quarter of a wavelength forward from said line. 1 sheet of drawings