Antenna array

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The solution relates to external feedback. circuit to reduce directional variation. of which beam angle in a number of antenna elements? The aperture switchgear (4) integrates with the sensing antenna aperture and produces a signal that represents the beam angle. The signal is detected, decoded, and converted to digital data for average and processing by the base unit (1G). The processed data is then compared to the value stored in the memory and any difference forms the basis of the correction signal. When applied to a microwave landing system, the correction signal is used to adjust the start / stop time of the antenna sensing command to correct the error without modifying the control beam algorithm. Independently of the feedback circuit, a spatially coupled monitor (7) may also be used to generate an alarm signal in response to any convergence of an associated aperture distributor (4), a self-stabilizing circuit or a series of antenna elements (1).

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276584 Βθ

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CS 276584 Βδ

The invention relates to an antenna system for radiating wave energy signals to a selected area in a desired radiation pattern, comprising a plurality of antenna elements defining and bridging aperture, distribution and coupling circuits, connecting antenna elements to a signal source and provided with variable phase shifters. and a beam controller controlling the phase shifters to form a beam emitted by the array for sequentially passing the selected space through the beam according to the beam control algorithm arising from the energy signals supplied to the antenna elements.

Sensing antennas and especially phased antenna series, how do we find them in microwave?

Landing waveguides that monitor the aperture of the antenna. In phased series, the bias error is independent of the angle in space. In contrast, the angle error in beam port antennas is angle dependent. Typically, these waveguides are weakly coupled to the aperture and could be used for manual detection of a series preload error caused by high frequency phase disturbances in the antenna circuit, for example due to temperature changes, temperature gradients and deterioration and exchange of individual components.

So far, such weakly coupled slit waveguides, when classed as monitors rather than simply as test devices, have been used to generate an alarm when an abnormal beam error has indicated either a malfunction of some of the sensing antenna component or the presence of an unacceptable temperature change; to an invalid gradient in the sensing antenna.

The purpose of the invention is to provide a scanning antenna having a self-stabilizing beam.

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Another object of the invention is to provide an apparatus which senses and corrects the feedback angle of the beam at an antenna with a plurality of antenna elements through the feedback circuit.

The invention is based on the fact that the antenna system comprises an aperture switchboard, the output of which is connected to an input of a signal evaluation circuit comprising a comparison base unit connected to the input of a beam control unit.

According to a preferred embodiment of the invention, the aperture distributor is directly connected to the aperture defined by the antenna elements and is provided with an output to show the direction of the beam direction.

According to another embodiment of the invention, a monitor with an output is spatially coupled to a plurality of antenna elements with free feedback to show the beam direction angle.

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Another embodiment is that the output of the spatial bound monitor is connected to an alarm. perimeter.

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According to a particular embodiment of the invention, the alarm circuit comprises a monitoring circuit whose input is connected to the monitor output and whose output is connected to one comparator input, the other input is connected to a memory storing the beam angle information, and the output is connected to alarm generator to trigger an alarm depending on the comparator output signal.

CS 276584 E6

According to yet another embodiment, the evaluation circuit comprises an aperture manifold output detector, a decoder associated therewith to produce an output corresponding to the beam direction angle represented by the detected aperture manifold output, and a base beam angle controlling unit according to the beam traverse algorithm and the decoder output.

Preferably, the base unit is programmed to modify the start and stop times of the beam, and the decoder is formed by a delayed processor.

The invention is based on the fact that the aperture switchboard, when properly positioned in front of the antenna, can instantly measure the true beam angle at a single switchboard output so that fast-reacting electrical circuits can generate and apply an error signal fast enough from the antenna beam to the desired level crossing despite the effects of temperature and other interfering factors affecting the level crossing. It is thus possible to achieve a self-correcting control of the directionality of the antenna system.

The new technical effect of the invention thus lies in the self-correcting control of the antenna system, which is made possible by the use of an aperture distributor to produce a signal to be used in the correction circuit for the beam control device.

The invention will be explained in more detail with reference to the accompanying drawing which schematically illustrates in a block diagram an antenna assembly according to the invention.

In particular, the invention is directed to microwave landing systems using a wide array of phasing antenna elements having a sharp cut of the element diagram as described in U.S. Pat. No. 4,041,501, which is hereby incorporated by reference. According to the illustration, such antenna systems comprise a row of one or more antenna elements 1 forming a row in which they are arranged along the axis of the row and spaced apart by a given distance. Each of the antenna elements. is coupled to the power divider 6 via a respective shifter from a plurality of phase shifters 9 connected to the antenna elements 1 of the distribution circuit 2. The wave energy signals from the signal generator 11 and the power divider 8 are fed to the antenna elements 1 of the phase shifter 2. values ​​for the sliders 9 cause the antenna elements 1 to radiate the desired radiation pattern to the selected angular area of ​​the space. Change of relative phase values ​​of shifters 9. the phase is performed by the beam control unit 10 through the control line 22 and causes the radiated antenna diagram to change direction with respect to the angle A in space. For this reason, the phase shifters 4 with the beam control unit 10 together form a device 3 for sequentially passing through the beam emitted by the array antenna elements 1 as a result of the supplied wave energy signals from the signal generator 11 coupled to the array elements 1 by the power divider 6 and the distribution circuit 2. .

The properties of the sensing antenna and techniques for selecting design parameters such as the length of the aperture, the distance of the antenna elements 1, and the particular configuration of the distribution circuit 2 are well known in the art. An overview of these parameters is perfectly described, for example, in US Pat. No. 4,041,501, to which reference is hereby made.

CS 276534 B6

To stabilize the beam direction angle, the aperture distributor g is associated with the antenna elements 1 of the row. The switchgear g may be any device for shaping the signal produced by the output 12, which represents the beam angle of the emitted beam. Preferably, the switchgear 4 is a highly stable waveguide, or it is a switch of special construction directly coupled to a series of elements 1 and centrally powered to avoid the related effects of phase and temperature. The center power supply also eliminates the primary dependence on frequency and absolute temperature changes.

The switchgear g of the present disclosure relates to any type of signal sampling device including a waveguide or power combiner. A stable switchgear is, by definition, a switchgear which is insensitive to frequency and temperature changes and is used in combination with the phase series of the invention to detect a bias error at a particular angle.

In its function, the switchgear g is equivalent to a probe placed in space at an angle to the phased array. The switchgear which can be used according to the invention may be a slit waveguide adapted to monitor the radiated energy so that the switchgear phase is zero at all sampling points. This zero-phase sampler ensures the central power supply of the cabinet g at all points.

The outlet 12 of the distributor g is coupled to a device g associated with the device g to control the passage of the radiated beam in response to the outlet 12 of the distributor g. In particular, the aperture distributor g used may consist of a waveguide which is an integral part of the antenna array. In microwave landing systems modulated according to the format specified by the International Civil Aviation Organization (ICAO), the switchgear g at output 12 produces a reciprocating beam signal emitted by a series of antenna elements 1. The reciprocating beam signal is detected by a diode detector 13 and amplified by an amplifier 14 . The detected amplified signal is coupled to an angle decoder 15, such as a delayed processor, where the signal representing the return moving beam is decoded to the directed beam angle and converted to digital data. The digital data is fed to the base unit 16 for processing. The base unit 16 includes stabilizing functional equipment that determines the direction of alignment of the array from this data and compares it to a predetermined value stored in memory. The difference between these comparison values ​​is the correction data that is fed to the beam controller 10. The unit 10 processes the correction data and uses it to adjust the control line 22 for the phase shifters g, thereby eliminating or minimizing any detected beam angle angle error.

The evaluation circuit g controls the passage of the radiated beam in accordance with the output 12 of the switchgear g. The base unit 16 is programmed with the start and end travel characteristics. The diode detector 13, amplifier 14 and angle decoder 15 detect the introduction and conclusion and provide this detected information to the base unit 16, which analyzes this information and starts the clock at the end of the introduction and stops the clock at the end of the conclusion. Between the beginning and the conclusion, the diode detector 13, the amplifier 14 and the angle decoder 15 continuously monitor the sensing angle of the beam emitted by the antenna elements 1 and received by the switchgear g. This continuous monitoring information is routed to the base unit 16 is discreetly sampled.

The sampled information is processed by the base unit 16 to determine the phase angle of the emitted beam. This phase angle is compared with the desired phase angle stored in the memory of the base unit 16, and any difference between the compared angles with the base unit 16 is converted into a control signal that is transmitted to the beam controller 10. After receiving the control signal, the beam controller 10 sets the values ​​22 for the phase shifter g according to this control signal. Preferably, the start / stop time may be overrun. The beam is set according to the control signal, thereby eliminating or minimizing any

CS 275584 B6

A volume routing error is detected. In this particular configuration, the control beam algorithm need not be modified. This cycle is repeated every time you pass.

As a result, the evaluation circuit 8 for the radiation beam override control will, in response to the output 12 of the switchgear 8, automatically stabilize the beam with a circuit independent of the antenna elements 1 in the form of detector 83, amplifier 14, decoder 15 and base unit 15. it responds to the output 12 of the external aperture monitor shown as the aperture distributor 6. In a preferred embodiment, the control signal generated by the base unit 16 is used by the beam controller 10 to adjust the phase shifter commands or the start / stop sensing beam in the case of a microwave landing system, so that the control beam algorithm is not modified by the beam self-stabilization.

The antenna elements 6 may consist of a slit waveguide cavity that is powered centrally to avoid frequency sensitivities within the 1.5 S bandwidth. The length of the waveguide cavity is designed to form a standing wave, with each wave having a constant phase. This can be achieved by a resonant power supply. Each standing wave halfwave is coupled to a radiating element (i.e., a slit in the case of a slit waveguide cavity). The waveguide is then provided within the ridge to achieve impedance matching. In the case of a slit waveguide, the ridge is located within the cavity of the waveguide. In such a waveguide configuration sc, the absolute power emitted by the waveguide can vary according to the emitted beam, but the relative power remains constant. For this reason, a stable switchgear can be directly coupled to a waveguide to accurately monitor bias bending.

The antenna system according to the invention may also be provided with a separate and independent circuit 6 including a field monitoring antenna 18 for monitoring the beam angle of the beam and generating a corresponding output signal 17. The field monitor 7 may be a spatially coupled monitor coupled to a field monitoring circuit 18 output signal 17 to a respective field signal 23 having a predetermined scale and magnitude. The circuit 18 transmits output information 13 to the comparator 89, which also receives output information from the memory 20. The memory 20 stores information regarding the acceptable beam angle of the beam at any time. The comparator 20 compares the output of the field monitoring circuit 13 with the information sampled from the memory 20 and actuates the alarm generator 21 if the comparison is outside a predetermined range.

for this reason, circuit 6 and field monitor 7 can be used to independently detect the failure of the switchgear, the automatic stabilization circuit, or the antenna array.

While a preferred embodiment of the invention has been described above according to today's ideas, it will be apparent to those skilled in the art that various changes and modifications to the apparatus of the invention may be made within the scope of the invention.