EP0000308B1 - Electronic scanning device comprising dielectric panels as phaseshifters - Google Patents

Description

The present invention relates to electronic scanning devices according to the preamble of claim 1 and described in documents FR-A-2 063 967 "New dielectric panels" and FR-A-2 224 887 "Light antenna for aircraft," and in particular the improvement of the device for supplying the bias voltage of the diodes resulting in a decrease in the value of this voltage, an increase in the frequency bandwidth of use and a decrease in the selectivity of differential phase shift.

It is of course possible, when it is desired to make continuous or cut metallic conductive wires carrying diodes placed in series, at a certain step on these wires, to supply these diodes with the same wire on which they are mounted, as provided for in the cited patents.

This way of supplying the diodes by the wire on which they are mounted is valid when the number of diodes carried by this wire is limited or when the bias voltage which it is necessary to apply in reverse to each diode to make the cut wire is weak.

However, this arrangement has a drawback when the number of diodes placed in series on the wire is large and when the unit voltage which must be applied in reverse to each diode is not very low.

Indeed in this case, the voltages which it is necessary to apply in reverse to each of the diodes to block it and make the support wire cut into sections, are added and it is necessary to apply to the ends of the wire considered a very large voltage which amounts to n (number of diodes in series on the wire) multiplied by v (reverse bias voltage of a diode), ie if n = 200 and v = 50 volts, a voltage of 10,000 volts.

Such voltage values require very high insulation between the different wires either from the same network of a phase-shifting panel or between the wires of the networks of adjacent phase-shifting panels or between the control wires outside the phase-shifting panels.

Similarly, these high voltage values make it very difficult to produce the supply devices which are responsible for supplying these voltages, for applying them to such and such a wire, and for cutting them, in very short times, for example 10 microseconds.

To avoid these drawbacks, the applicant has invented a device for supplying diodes mounted on a conductive metal wire intended to be made at will continuous or interrupted in sections according to the state of these diodes, either polarized in direct, or polarized in reverse. , this poretur diode wire forming part of the networks of metallic wires constituting the phase-shifting panels which are the subject of documents FR-A-2 063 967 and 2 224 887. This device allows a power supply by introducing additional control wires, makes it possible to power simultaneously all the diodes of the same wire and does not require the use of very high supply voltages which are disruptive for the diodes as well as for the control circuit external to the phase shift panel, and which moreover makes it possible to increase the width of the frequency band of the panel use waves and allows better control of the value of the differential phase shift between the two states of the phase shifter panel as the wires carrying the diodes of the networks are electrically continuous or cut off.

The electronic scanning device according to the invention is characterized in that the continuous conductive wires are used to supply voltage by group to the diodes placed in series on the wires carrying diodes.

Dependent claims 2-4 relating to particular embodiments of this invention.

A description is given below, by way of nonlimiting example, of the supply of the diodes of the network of wires carrying diodes constituting a phase-shifting panel with reference to FIG. 1 of the single board.

Two sheets of (1) glass-polyester resin laminate 0.5 mm thick and 3.6 dielectric constant were bonded to each side of a sheet of honeycomb dielectric material (2 sheets). 2) of thickness g = 22 mm and of dielectric constant 1.4 a square dielectric panel of 1000 x 1000 mm.

On each of the two laminate sheets is deposited a network of metallic wires, the repeating pattern of which consists of a wire (3) on which are mounted 8 groups of 10 identical diodes (4) and (5), of two continuous wires ( 6) and (7) located at a distance (b) of 8 mm on either side of the diode-carrying wire, of a wire (8) located 12 mm (c) from each above motif cut in equal sections of d = 34 mm in length separated by cuts of (e) 0.3 mm. All the diodes (4) or (5) are identical and mounted at a constant pitch (a) on the wire (3) whose diameter is 0.4 mm.

On a wire (3) all 10 diodes of the same group are mounted in the same direction, the 10 diodes of the next group are mounted in the opposite direction to the previous one.

The two continuous metallic wires (6) and (7) which frame the wire (3) are 8 mm on either side of it, the diameter of the wires (6) and (7) is 0.22 mm.

Conductive strands (9) of 0.22 mm in diameter connect the points of the wire (3), located at the beginning of a group of diodes of the same direction to the wire (6); identical conductive strands connect the joints of the wire (3) located at the end of these same groups of diodes to the wire (7). One end wire (6) external to the panel is connected at will to a voltage source of 500 volts, the end of the associated wire (7) being simultaneously brought to zero voltage. Therefore all the diodes (4) and (5) are supplied in reverse under the average unit voltage of 50 volts necessary for their blocking. The wire (3) becomes discontinuous and cut into sections of identical unit length defined by the pitch of the diodes (a).

At will the wire (6) is brought to a zero voltage and the wire (7) to a voltage of 5 volts. All the diodes (4) and (5) of the wire (3) are then supplied directly. The wire (3) is continuous and traversed by a current of two milli-amps.

The panel thus formed is suitable for transmitting waves of 3000 MHz frequency, when the diodes on both sides of the panel are in the same state.

This adaptation in the two states of the diodes results, for a state of the diodes of the spacing and of the constitution of the two laminate sheets (1) produced according to the so-called sandwich technique and, for the other state of the diodes, of the relative positions different metallic wires (3) (6), (7) and (8) and their microwave function on the incident radiation.

The differential phase shift due to the crossing of the panel by the microwave wave of 3000 Megahertz with polarization parallel to the networks of wires, for the two states of the diodes is 42 degrees and the attenuation is less than 0.12 decibel.

The device for supplying the bias voltage of the diodes of a microwave phase shifting panel using networks of metal wires, such as, for example, that which has just been described, have numerous advantages.

The value of the voltage which must be supplied to make the diode-carrying wire cut into sections is greatly reduced and is no longer equal only to the product of the value of the reverse bias voltage of a diode by the number of diodes belonging to the same group. By this supply device it is possible to limit the value of this voltage to less than 500 volts.

This results in a very great simplification of the devices external to the panel for supplying and switching this voltage. The electrical insulation between the different control wires can be reduced in the voltage ratio.

The external connections to the phase shift panel concerned can be grouped on the same side of this panel. The voltage supply wires of the diode groups are integrated into the panel and, according to the state of the art, these continuous wires also have a microwave function improving the possibilities of adaptation of the panel in a larger frequency band. The device according to the invention can be applied to arrays of metallic wires enabling it to be applied to the power supply of the diode lines of the various panels constituting active lenses allowing the electronic scanning of a microwave beam in the plane perpendicular to the arrays of sons.

Claims (4)

1. Electronic scanning device comprising dielectric dephaser panels including networks of continuous conductive metallic wires intended essentially for the adaptation of the panels to the length of the electromagnetic wave transmitted, and of networks of conductive metallic wires carrying diodes arranged in series, intended according to their state to convert or disconnect the conductive metallic wires on which they are mounted, characterised in that the continuous conductive wires are used to supply voltage in groups to the diodes arranged in series on the diode carrying wires.

2. Electronic scanning device according to Claim 1 characterised in that each wire carrying diodes is associated with two continuous wires, located on either side of the diode carrying wire at such a distance that the assembly of conductive wires associated with the dielectric material of the panel adapts this latter to the transmission of the wave of a chosen frequency.

3. Electronic scanning device according to Claim 2, characterised in that on a diode carrying wire is alternately mounted a group of diodes in series in one sense, a group of the same number of diodes in series is mounted in the opposite sense, each of the diodes being supplied by the wire on which they are mounted, the groups of diodes mounted in series receiving the voltage by means of the two continuous wires which are associated with this diode carrying wire, by virtue of conductive bridges situated at each end of the groups of diodes and alternately connecting one of these two continuous wires to the diode carrying wire.

4. Electronic scanning device according to Claim 3, characterised in that the number of diodes of a group of diodes mounted in series on a diode carrying wire is determined as a function of the voltage which it is desired to apply, the insulating properties achieved in and on the outside of the panel between the various conductive wires, and the cross-section of these wires.

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