JPS63500698A - beam steerable antenna - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Beam steering 40 antenna This invention was made under Contract No. F49620-82-C-0099 awarded by the Department of the Air Force. This invention was made under the auspices of the United States Government. have certain rights to

light 1 The present invention provides a directional antenna that includes interaction between a dielectric waveguide and a periodic structure in its vicinity. Regarding the na system. The period of the near-periodic conductor structure can be varied over a continuous range. Changing the angle of maximum radiation or reception of the antenna by making it Particularly useful.

Beam steerable antennas are used in radar and exploration systems, communication systems, and satellites. It has applications such as in television reception. beam steerable antenna or There is a need for an easy, low-cost method to configure phased arrays. are doing.

Traditionally, microwave phased arrays have been trisic nc4ative) diode or ferrite device The beam tfil& is achieved by a high speed phase shifter consisting of: These phase shifters sets the electrical phase of the elements of the array. Extremely high operating frequencies (e.g. (for example, in the millimeter-wave region of the spectrum). It is difficult and expensive to do so.

Another abrogation is based on "diffractive electronics." dielectric waveguide The closely spaced periodic structure imposes a periodic boundary condition, which The periodic structure provides radiation lobes. Fixed periodic made from grooved metal blocks Experiments have been reported for this type of binding structure using the structure [S,D , Δndrenko, V.

(,, BeNyaev, N, E, Devyatkov, and V, P, 5 hestopa#ov, r Diffraction input of energy to dielectric waveguide "Dif fraction 1nput or Energy to a Dielec tric Waveguide”, DokN, Δkad, Nauk SSR , 247, pp. 73-76 (July 1979)]. This kind of lecture structure The structure is shown in Figure 2. Repeat intervals along the entire length of the periodic structure! but This is the period of this periodic structure. The maximum radiation from the dielectric waveguide (also is reception) direction (angle θ) is set by the period r of the periodic structure.

What is shown is that the periodic structure is stronger at the supply end of the waveguide than at the load end of the waveguide. tilt slightly (angle α in Figure 2) to generate a smaller coupling of It should be [S, D, ^ndrenko, N, D, DevyaLk ov, andV, P, 5hestopaNov, r mm feel "Mi1i!imeLer Field Ba nd Antenna Arrays”, Dokl, ^kad, Nauk 5S SR, 240, l) p 1340 1343 (June 1978)]. given Because of the maximum radiated power in the direction of It is optimal when it is uniform along the .

For best performance, there is an optimum distance between the dielectric waveguide and the conductive surface of the periodic structure. (for example, the nominal distance ω in FIG. 2). If the periodic structure is placed too close to the waveguide Then, the excitation becomes non-uniform and the radiation lobe becomes poorly defined. If the structure If the wave tube is too far away, no radiation will be generated. The optimal distance and tilt is , optimally determined by experiment. A properly adjusted periodic structure will reduce the total input power Approximately 90% can be radiated into the dielectric waveguide.

The fixed period p (meters) of the periodic structure and the direction of maximum wave propagation (with respect to the loaded end of the waveguide) The relationship between the angle θ (measured in radians) can be obtained from theoretical considerations.

The interaction between the waveguide and the periodic structure via evanescent mode coupling is This causes surface excitation of the phase structure. The propagation constant of the fixed periodic structure is F4 oquet) given by the theorem [J, C, S&ater, r microwave Electronic Engineering “Microwave Electronics”, D. Van No5trand Co.

p 170 (1950)].

Bs = Bo + m2yr/l (1) However, B, = propagation constant of the dominant guided mode, m-'p-period of the periodic structure, m m = number of modes = 0. ±1, ±2, ... due to radiation from the waveguide-periodic coupling structure The condition for this is that the wave in the radiation direction θ must satisfy the following condition. be.

kocos θ = Bs: Bo + m2yr/l (2) However, k o = 2π/λ - free space propagation constant, m - 'λ = free space wavelength, m θ - angle from the axis to the load end of the waveguide, radia where the radiation condition is: cos θ = B o / k o + m λ/1 (3) cos θ = c/vg +mλ/Q, (4') However, C - free space velocity at the tip, m/s e cvg = propagation velocity in the waveguide, m/s ee The normal radiation mode of interest is associated with m=-1.

There is one dominant radiation lobe for the following conditions:

c/vg+1>λzQ>c/vg-1<5) As is clear from equation (4), The beam directivity angle θ is inversely proportional to the period l of the periodic structure. Therefore 5 desired fixed orientation A waveguide-periodic coupling structure with an angle θ can be constructed by using a period i structure with a fixed period p. 6 Andrenko et al. (1978) has period l. A fixed periodic structure consisting of a grooved metal block as shown in Figure 2 as a "diffraction grating" is mentioned. They are on a cylindrical barrel that rotates around its own axis their mm-band antennas by attaching diffraction gratings of different periods to ・It describes the possibility of adjusting the directivity in an array in stages. deer However, they suggest only discrete changes and are not directional over a continuous range. There is no mention of how to change the.

If the period of the periodic structure is adjustable over a continuous range and the period e is to adjust quickly and thereby over a continuous range such as that provided by the present invention. More flexibility is provided if means are provided to obtain the desired beam angle. A practical device will likely be obtained.

1st generation The present invention allows the beam to be steered over a wide range of angles relative to the axis of the antenna. directional antenna system. Electromagnetic energy at the frequency that the waveguide propagates This beam-steering antenna for transmitting and/or receiving It is based on the principles of "engineering". A typical beam steerable antenna is a dielectric waveguide antenna. tube and adjustable in a longitudinal region adjacent to and substantially parallel to the waveguide. It has a periodic structure.

A typical adjustable periodic structure can consist of a coiled helical spring; In this spring, the conductive portions of the wire are evenly spaced; The spring is then stretched or stretched to change the spacing between the coils of the spring. is provided with means for compressing it.

The spring typically includes a metal core to guide its helical coils. I'm here. The distance between the periodic structure and the dielectric waveguide and its axis relative to the dielectric waveguide Even small tilts can be adjusted for maximum power.

Another adjustable periodic structure used in the present invention is a bellows-like flexible member, a movable A chain, and a threaded polyhedron. Adjusting the interval” means 1 is linear Select as appropriate for the type of periodic structure such as actuators, motors, and solenoids. This will be clear to those skilled in the art.

For example, periodic structures in the form of hollow bellows can increase or decrease air pressure. You can adjust the spacing by doing this.

In an alternative embodiment of the invention, the adjustable periodic structure may be a thin metal tape or is on metallized tape.

This moves between the storage reel and the take-up reel to create an intervening thrower 1 in the tape. to a tape location containing the desired spacing of conductive lines formed between. or Alternatively, conductive elements with the desired spacing may be Computer-controlled conductive ink jet printer for forming tape printed onto non-conductive tape by a printer.

In another embodiment of the invention, the tunable periodic structure comprises a photoconductive surface. , which creates a moiré pattern with a frequency proportional to the adjustable angle between the lines on the two gratings. generated by light diffracted by overlapping transparent standard gratings forming stripes. It has periodic conductive bands.

In another embodiment of the invention, the tunable periodic structure comprises a photoconductive surface. , this can be the light diffracted by an acousto-optic device or a diode laser. by optically focused light generated by computer-controlled selective activation of the array. It has periodic conductive bands generated by

In another embodiment of the invention, the adjustable periodic structure is adapted to accommodate electron beams within the diameter tube. consists of periodic conductive bands in adjacent semiconductor surfaces that can be adjusted by controlling the There is.

l1 FIG. 1 is a schematic front view of the test equipment, which shows a dielectric waveguide according to the invention. used to measure the beam pointing angle resulting from the interaction of the tube with an adjacent periodic fit structure. used.

Figure 2 is an enlarged schematic front sectional view of the waveguide and periodic structure as in Figure 1. Yes, indicating important dimensions.

FIG. 3 is an enlarged schematic front view of a waveguide as in FIG. 1, with an adjustable The periodic structure consists of spring parts.

Figure 4 shows the relative beam power and beam at several frequencies for a fixed period. Figure 3 is a graph of data showing changes in angle;

Figure 5 shows the waveguide-periodic structure of Figure 3 at one spacing of the coils of the spring. 2 is a graph of relative power versus beam angle for FIG.

FIG. 6 is a graph of data for the waveguide-periodic structure of FIG. Therefore, as a function of the period resulting from adjusting the spacing of the coils of a periodic spring structure, shows the beam direction angle.

Figure 7 shows the linear correlation of half-power beamwidth as a function of wavelength, period, and beam angle. It is a graph of data showing.

Figure 8 shows a modified spring coil waveguide-spring adjustable period. FIG. 3 is a partial sectional axial view of the structure.

FIG. 9 is a partial cross-sectional axial view of one coil of the modified helical spring.

FIG. 10 is a partial sectional axial view of one coil of a square spring.

FIG. 11 is a schematic perspective view of a bellows-like adjustable periodic structure;

FIG. 12 is a schematic diagram of an adjustable bellows periodic structure and waveguide.

FIG. 13 is a schematic diagram of the adjustable periodic structure and waveguide of the motion chain.

FIG. 14 is a schematic perspective view of an adjustable periodic structure of a variable pitch screwed polyhedron. Ru.

FIG. 15 is a schematic diagram of the adjustable periodic structure of the movable tape and the waveguide.

FIG. 16 shows the waveguide of FIG. 15 and the conductive ink on the tape of the adjustable periodic structure. FIG. 2 is a schematic perspective view of a link line;

FIG. 17 is a schematic diagram of an adjustable periodic structure of the type of preformed perforation tape. It is.

FIG. 18 shows a waveguide and an adjacent photoconductive surface tunable by an optical grating. FIG. 2 is a schematic cross-sectional view of a periodic structure consisting of periodic conductive bands.

FIG. 19 is a partial cross-sectional view taken along line 19-19 in FIG. 18.

FIG. 20 is a schematic diagram of the moire fringe pattern shown at 20-20 in FIG. 18.

Figure 21 shows a waveguide and an acousto-optic device generating multiple light beams. A periodic structure consisting of periodic conductive bands within collapsible adjacent photoconductive surfaces. This is a schematic diagram.

FIG. 22 shows a waveguide and an adjacency adjustable by an acousto-optic light scanning device. 1 is a schematic illustration of a periodic structure consisting of periodic conductive bands within a photoconductive surface; FIG.

Figure 23 shows waveguide and diode laser array activation computation. Periodicity within adjacent photoconductive surfaces tunable by data control and optically focused light FIG. 3 is a schematic diagram of a periodic structure consisting of conductive bands.

Figure 24 is a schematic diagram of a dielectric antenna. It shows the direction of radiation.

25th [2I is a schematic diagram of a dielectric antenna, and a table of a periodic structure on the antenna. Shows the direction of radiation relative to the surface.

FIG. 26 shows a waveguide and an adjustable adjacency by controlling the electron beam in the cathode ray tube. 1 is a schematic diagram of a periodic structure consisting of periodic conductive bands in a contacting semiconductor surface; FIG.

FIG. 27 is a cross-sectional view taken along line 27-27 in FIG. 26.

Male 3JuU- The test facility in Figure 1 is constructed after first activating this test facility in a periodic structure with a fixed period. For the adjustable periodic structure according to the invention, the beam steering angle as a function of the period l is It was used to measure θ.

A standard horn antenna 20 is used to measure its radiation pattern and The thermistor 21 and wattmeter 22, which were calibrated using the same method, acted as a detector. 0.6m The arc radius of ensured that the horn was in the far region of the radiation pattern.

The test facility was designed for an operating frequency of 94 GHz. CW Crys 1~Ron 23 is used as a source of electromagnetic energy, which includes a circulator ( An isolator) 24 and a frequency meter 25 were provided. Standard W-band waveguide A termination 26 is used at the load end, which includes another thermistor 21 and a wattmeter 22. It was connected by a 20dB coupler 27.

The dielectric waveguide antenna 28 is constructed in a test facility via two lengths of WR-10 waveguide. connected. Polystyrene (εr=2.56) was used for the dielectric. , and the same nominal cross section as the slot in the metal waveguide (i.e. 0.127x It was cut to have a diameter of 0.254 cm. The dielectric strip is about 10 cm long and a few millimeters back from either end. To do this, its top and bottom surfaces were tapered into a wedge shape. Electric field probe (as shown) (without periodic structure) is fabricated and used with a quartz crystal detector to The electric field along the electric body 28 was examined. The wavelength (λg) of the dielectric strip 28 is 94 It was found to be 2.6 mm in Hz.

To verify this test facility, a periodic plus structure 30 was fabricated, which Period ff1 = 2.2mm, notch depth 0.67mm, and 50% duty cycle. 0 period structure with a length of 30 periods L = 66 mm) 30 is placed on a tilt stand 31, and as shown in FIG. (approximately 10-20 mrad) between the periodic structure 30 and the dielectric waveguide 28. The nominal distance ω was 1 mm. In the above periodic structure 30, the beam angle is λ= It is 1.03.75° at 94 GHz, and from equation (4), the effective propagation constant ( c/vg) was found to be 1.22. This value was measured with an electric field probe. It matched the wavelength of the dielectric waveguide. This generator frequency is determined by varying the beam angle θ at the wavelength λ. was varied over the range 9l-98 GHz to determine the Shown in Figure 4. To validate this test facility, it is important that the data match equation (4) well. deemed sufficient.

In order to investigate the effect of the adjustable periodic structure, a spring 32 as shown in FIG. It was used in place of the fixed periodic structure shown in FIG. The spring 32 is expressed by formula (5) can be stretched or compressed to vary the period p over the range shown in was selected so that it could be done. Such readily available springs are 5. It consists of 32 helical coils with a diameter of 5 mm and a wire diameter of 0.5 mm. Ta. A 5 mm diameter Phillips rod was used as the core 33.

This spring 32 initially moves the actuator 34 against the stop member 35. The distance between the coils was adjusted by 12 = 2.2 mm (using the test equipment) (identical to the fixed period of the structure 30 used to create the structure). The resulting radiation pattern The beam is shown in Figure 5, which is scaled to the gain at beam maximum. (The spring's "gain" is about 5 dB lower than that of the Plus Ti 30) . Tilt was not imparted to the spring.

The length of the spring 32 steers the beam from the angle θ・166° to θ=80°. In order to turned into The change in the orientation angle θ with respect to the spring coil spacing or period r is determined by the sixth As shown in the figure. The measured values in FIG. 6 are c/vg=1.22. m=-1, and ^=3.19, showing good agreement with the theory based on equation (4).

The results shown in Figure 6 demonstrate that the waveguide and adjustable frequency A directional antenna system comprising a spring as a primary structure is provided according to the invention. The beam steering also adjusts the period or spacing of the conductive coils of the spring. This can be achieved by making adjustments.

It turns out that the positive rod 33 has a length comparable to the length of the spring 32. The best radiation efficiency is obtained when Therefore, three different This accommodates a spring length change of 66mm ± 50% using the rod length. Accept the cycle! and the resulting change in beam angle θ was obtained.

Essentially, a "diffractive electronics" antenna is a self-exciting array whose periodic structure Each element is driven in series.

The total length of the array can represent the half-power beamwidth of the radiation pattern as shown in Figure 3. expected. This half-power beamwidth Δθ (radians) should be approximately be.

Δθ~λ/(Lsinθ)=(λ/L)cscθ Spring 32 shown in FIG. In the experiments described above, the 3 dB beam width was Measured at These values are plotted in Figure 7, and the results are expressed as equation (6) and Match.

Regarding the present invention, the simplest embodiment, an adjustable periodic structure, is as shown in FIG. A possible embodiment of a conventional helical spring 32 has been demonstrated and described. The term “S” "Pulling" is used in its broadest sense of achieving the intended function; may have a somewhat different configuration than conventional springs in some applications. . For example, FIG. 8 is an enlarged partial axial view of spring 32'' on core 33. , the spring has a slightly flattened surface 36 adjacent the waveguide 28. , whereby the distance ω is equal to the variable distance of the conventional spring shown by the dotted line 38 in FIG. In comparison, the width of the waveguide is more uniform down the width.

FIG. 9 shows another modification of the spring 32'', which has a helical coil. One section has a raised flat surface 36' parallel to the waveguide, which is a spring It is advantageous if the waveguide diameter is small relative to the width of the waveguide.

Figure 10 shows another modification in which the three coils of the spring are not circular. The cross section of the wire can be rectangular rather than circular, and the The cross section of A 33' can be rectangular rather than circular; During adjustment of the spring, the three individual coils slide flat along the core 33'. It is advantageous to keep the curved surface 36'' parallel to the waveguide 28.

The springs shown in Figures 3, 8, 9, and 10 have an adjustable periodic structure. For certain embodiments of the invention, the control means described above may control the length of the spring and thus the length of the spring. It consists of means for varying the spacing between corresponding points of successive turns and thus the period p. this The control means is typically an actuator 34 as shown in FIG. , connected to one end of the spring and the other end of the spring fixed to the stop member 35. When pressed, essentially imparts axial movement of the spring in either direction. each Various types of linear actuators, e.g. pneumatic actuators, hydraulic actuators motor, motor-driven screw actuator, solenoid actuator, or other means known to those skilled in the art can be used.

FIG. 11 shows another embodiment of the invention in which the adjustable periodic structure 40 is a bellows-like flexible member, the outer edges 41 of which define spaced apart locations; are doing.

FIG. 12 shows another embodiment in which the adjustable periodic structure is -42, and the control means can be an air supply source 43, which controls the air pressure. By varying the length of bellows 42 and the spacing of its outer edges 44 affect.

FIG. 13 is another embodiment of the invention in which the adjustable periodic structure It is a moving chain 45, which consists of multiple isopod drag links 46 (extendable pincers). , the conductive portion 47 of which is approximately equally spaced apart from the drag link. connected by a terval.

FIG. 14 shows another embodiment of the invention in which the adjustable periodic structure The structure consists of identical polyhedra 48 that are approximately equally spaced, and these polyhedra are A cylindrical member with multiple sections threaded with pitch screws to four external threads. Internally threaded to fit. No need to move along the cylindrical member 49 The first polyhedron 48 may be on the unthreaded portion of the cylinder 49'. No. The polyhedron 48' of 2 has adjacent threads having x threads per unit length of the cylinder. It is installed at 50 minutes. The second polyhedron 48'' has 2 polyhedrons per unit length of the cylinder 50'. attached to the next adjacent part with X threads, and likewise the last polyhedron 48n is the last [(n-1 , ) is attached to the threaded portion 50n-1. Polyhedron 48.48°, 48 ”, 48n of the polyhedron while allowing axial movement along these four cylindrical members. In order to prevent rotation, it is restrained by a guide member 51. The control means 34 In order to rotate the cylinder 49, a polyhedron and a dielectric waveguide (not shown in FIG. 14) are used. ) are provided to vary the spacing of the conductive surfaces 47° adjacent to the conductive surfaces 47°.

15 and 16 show another embodiment of the invention in which the adjustment A possible periodic structure is the separation of conductive ink on a non-conductive paper sheet 153 as shown in FIG. The paper tape consists of a line 52 spaced between the paper tapes and the feed spout as shown in FIG. It is moved at high speed between the take-up spool 54 and the take-up spool 55. This conductive ink The line is moved at high speed before the tape moves approximately parallel to the axis of the adjacent waveguide 28. The tape can be formed virtually instantly by the jet printer 56. These conductive The spacing of the ink lines 52 is controlled by controlling the speed of the tape 53. Ru. 15 [21 and 16] These embodiments of the invention shown in FIGS. For example, a high-speed jet printer 56 can make changes as fast as 10 seconds per second. ,000 lines, and if you generate 50 lines with a beam angle of 1~ When used in the field, approximately 200 beam angle changes per second can be achieved. Period l=2 mm, the tape speed is on the order of 20 meters per second.

Another variation of the above embodiment includes conductive spaced apart parallel lines on a non-conductive tape. The method is to use a pre-formed tape that is coated with conductive ink. can be made by a jet printer or other means.

The parts of the tape that are the length of the waveguide (e.g. 100 mm in the previous example) are: contains evenly spaced lines of period p, and adjacent parts of the tape have a value of including equally spaced lines of different periods I+Δp, and so on, thereby so that the entire tape contains multiple sections with conductive lines of slightly different periods. It was done. Move the tape between two spools to get the desired cycle! Te with a line of The means for moving the loop portion into a position adjacent to the waveguide is determined by the periodicity and the period of the structure. Control the beam directivity angle θ.

Another modification of the above preformed tape is shown in FIG. Adjustable period f! The structure consists of parallel holes 58 separating five parallel conductive lines. These holes can be formed by mechanical drilling, electroforming, or other methods known to those skilled in the art. A suitable tape (e.g., thin metal tape, metal-coated tape, or can be preformed on the conductive coating of the tape).

18, 19, and 20 illustrate another embodiment of the invention, in which the adjustment A possible periodic structure consists of a photoconductive surface 60 whose periodic conductive bands are More generated from transparent standard gratings 63 and 64 superimposed by light from source 61 It is generated via the stripe band 62.

The gratings 63 and 64 are adjacent and parallel to the dielectric waveguide 28 over its length. , and one end of it is fixed with a bond for the flexibility grid. For solid or rigid grids, it is fixed by a pivot and the other end is attached to the grid surface. They are movable relative to each other in a plane parallel to the plane.

The bright band 62° and the dark band 62 that intersect with the period p shown in FIG. It results from the relative movement of these gratings at a distance of X per florescence length of child L'. photoconductive layer The bright band 62', which generates a conductive band within the waveguide, is caused by the relative movement of these gratings. If it is symmetrical about six axes (i.e., x' = x'' in Figure 20), then and is oriented vertically. The required relative movement x/L’ of those grids is small, This is therefore suitable for various means, e.g. for twisting the lever 65 with the pivot 66. This can be achieved by a simple lever device 65 shown in FIG. 19 connected to a suitable actuator. Can be done. For example, if parallel grid lines 67 and 68 are 6 micrometers If it has a period, the relative movement of x, = 0.042 mm is the distance L' = 15.4 It is possible to generate eight stripes as shown in Fig. 20 with a period N = 2.2 mm over a length of It becomes. Therefore, for a waveguide and grating length of 100 mm, 1.40. 2.20. and the fringe period p of 3.20 mm is 0.428, 0.273 and 0, respectively. ．． A relative movement X of 187 mm is required.

21, 22 and 23 show another embodiment of the invention, which The beam steering of the antenna is accomplished by non-mechanical means. its adjustment A possible periodic structure consists of a thin photoconductive surface 60 on a transparent substrate 70, with its periphery The periodic conductive band 62° is inserted into the photoconductive material by the rays 71, 71' and 80. are generated and the beams are adjustable where they impinge on the photoconductive 600 surface. They are uniformly spaced apart by a distance e that can be used. In each example rays 71, 71' and 8 There are several ways to control 0.

In FIG. 21, a laser 90 or other light source is applied to an acousto-optic device 73. The light is then diffracted into a plurality of separate light beams 71. This device 73 is often It is called a Bragg cell and is used for spectral analysis. There is. This Bragg cell is usually made of glass or a crystal such as lithium niobate. It is a block of body material, and the cross section is 1 cm x 1. c m, 10 -The length is up to 20 cm. A piezoelectric transducer 74 is glued to its end. converter When 74 is excited by an electrical signal 75, a traveling acoustic wave 76 is established within the material. It will be done. This acoustic energy is transformed into a refractive index between the acoustic pressure peak 76 and the valley. It brings about change. When light 72 is introduced at the correct angle β, the result from this refractive index change is Reflections add phase and Bragg diffraction occurs. A portion of the input optical beam 72 is is deflected and imaged onto a photoconductive surface 60''. This bias α is the drive signal is proportional to the acoustic frequency generated by acoustic transducer 74 in response to 75. If so When the drive signal 75 includes many signals with different frequencies, many diffracted light beams are generated. 71 will result. Therefore, if those multiple signals of drive signal 75 are uniform If the frequency sequence f, f+Δω, f+2Δω, f+3Δω, -−f+nΔω, In this case, multiple diffracted light beams with angles α, α0 to X, α+2ΔX, α+3ΔX, α10nΔX are beam 71 produces evenly spaced conductive bands 62° within photoconductive surface 60. That will happen. Since this spacing r of the conductive bands is proportional to the incremental frequency Δω , l can be adjusted by adjusting its incremental frequency Δω, thereby The beam [is achieved by changing the beam angle θ with respect to the axis of the dielectric waveguide.

Another variation using a similar acousto-optic device 73 shown in FIG. It acts as a scanning device as shown in Figure 2. Laser beam 72 is a piezoelectric Frequency f of drive signal 75'' for converter 74, f+Δω, f+2Δω, f+3Δ Continuous changes in ω, f+nΔω create continuous angles α, α+ΔX, α+2ΔX, It is rapidly diffracted at α+3ΔX and α+nΔX. Sweeping speed of the diffracted beam 71° (a complete cycle of discrete frequencies) is the inherent decrease in conductivity within the irradiated photoconductive material. The decay rate is faster than that.

In one embodiment shown in FIG. 23, the light source is a plurality of individual laser diodes 7. a laser diode array 77 consisting of eight laser diodes 78; ffl selectively activated by computer 79 to generate individual beams 80. Ru. A convex lens 8] is used to focus the light beam 80 onto the photoconductive surface 60. Ru. A sufficient number of laser diodes 78 are used in the array 77 to Therefore, by computer-controlled electrical activation of the selected laser diode, , a periodic conductive band 62' with an adjustable period p passes the beam 82 through an angle θ. is generated on the photoconductive surface 60 for steering purposes.

21, 22, and 23, the beam 82 is connected to the dielectric waveguide 28. is schematically shown radiating in a direction 82 opposite to the periodic conductive structure 60 from ing. It should be understood that this antenna is also shown in Figures 24 and 25. As shown, the power is transferred in the opposite direction 82' (1! II, angle θ''zθ+180 °) also radiates.

24 and 25, the periodic conductive surface 83 is connected to the dielectric waveguide 28. is indicated by a dotted line close to . Evanescent mode coupling is due to its periodic structure8 3 to generate surface excitation. This periodic structure provides a thin film that hardly blocks the beam. The photoactivatable conductive band 62' in the photoconductor 60 (FIGS. 20-23) When it is very thin, as shown in Figures 24 and 25, the power is is emitted not only in the direction 82 but also in the direction 82''.The surface 83 of this periodic structure A section of bulky metal 30 or similar beam stop 183M as shown in FIG. (for example, wire 32 on metal core 33 in FIG. 3), the main radiated power is in the beam direction 82 at an angle θ' and in the beam direction 82' at an angle θ'. There is no radiated power, as shown in Figures 24 and 25, the beam angle is arbitrarily measured from the load end of the body waveguide 28 opposite the supply end. power to antenna The feed is indicated by arrow 84. Typically, the adjustable periodic structure 83 can be adjusted as desired. is placed on the dielectric waveguide 28 on the side opposite to the beam propagation direction 82 of FIG. Avoid interference with the beam as shown in . Figures 21, 22, and 23 For an adjustable period IjI structure as shown, the photoconductive surface 60 is a dielectric material. can be placed on top of the waveguide 28 and by using mirrors or other means. The light beam is directed toward the photoconductive surface 60, thereby producing a tuning effect as shown in FIG. Minimize interference with the beam 82 propagating in the direction of the articulating periodic structure 83. 42.

For example, in experimental studies using the apparatus shown in FIG. , was placed close to the top of the dielectric waveguide 28 (ω-1-5 mm). this The photoconductive surface is 1 micrometer on a transparent substrate of glass (microscope slide). N-type amorphous silicon in thin film thickness (approximately 2000-3400 ohm-c m dark resistivity). The surface on the opposite side of this substrate 700 (in this experiment The upper surface) has alternating opaque lines and transparent lines with a period f = 2.1 mm. It included a face mask. The photoconductive surface is coated with a far laser (Nd:YAG, 1°0 6 micrometres, 16 millijoules per pulseless, 10 pulses per second, pulse It was irradiated for 3 nanoseconds per spot. This laser beam has a diameter of 6.3 cm. Expanded to fill the reflector. The reflected beam is transmitted through a cylindrical lens (400mm focal length) and thereby close to the polystyrene waveguide 28 A 3 mm rectangular area was irradiated. The grating surrounds 30 optical bands of lmm x 3mm. occurs at periods N = 2.1 mm - each of which is approximately 20 microns per laser pulse. I received the Juyur. For this period, the beam measured in the apparatus of Fig. The angle was θ=7 because its periodic conductive surface 83 was at the top as shown in FIG. It was 6°. If the same periodic conductive surface 83 is used as an antenna as in FIG. If it were used under Na28, its measurement beam angle θ would be 104°. There would have been. This angle is similar to that of a klystron saw operating at a frequency of 94 GHz. This corresponds to the data in FIG. 6 for similar conditions at step 23. shown by experiment is the periodicity t! of photoinduced conductive bands within the photoconductive surface 60. 4th structure is bi The periodicity shown in Figure 2 plus lateral 35a30 was achieved. 9 As shown in Figure 23, results similar to those of photoconductive surface with uniformly spaced conductive bands adjustable by computer control of the light source. It is advantageous to use the Bee-11 steerable antenna, which is a non-mechanical Figures 26 and 27 show that the beam angle can be rapidly adjusted by means of the present invention. Another embodiment is shown in which the beam ti1jM of the antenna is connected to the cathode This is achieved by non-mechanical means using wire tube (CRT) technology. This adjustable The periodic structure consists of a semiconductor thin film 92 whose periodic conductive bands 94 are At the point where the electron beam 90 collides with the semiconductor thin film 92, the electron beam causes generated on a thin film. This embodiment of the invention is shown in FIGS. 21, 22 and 23. Using an electron beam 90 instead of the beam 71.71'-80 as in the figure, Adjustable periodic structure 92 must therefore be housed within vacuum tube 86. C R,T technology provides evenly spaced adjustable distances! The position of the conductive band 94 is used to control.

The cathode ray tube 85 is typically a vacuum tube 86 made of glass, typically a research tube. An electron gun 88 and an electron beam 90, which are used in the oscilloscope at It consists of means 87,87' for deflecting. The beam control means 87' As shown, it is used to write conductive bands 94 within a semiconductor thin film 92. Ru. The beam control means 87 shown in FIG. 26 controls the scanning of the grass by the electron beam 90. is used to write a plurality of spaced apart conductive bands 94 within the semiconductor thin film 92 during the process. It will be done. The number of conductive bands 94 written across the semiconductor thin film 92, and hence it The period p of these determines the beam steering angle θ of the radiation beam 82.

Appropriate electrical signals are generated to the beam control means 87, 87' and the semiconductors ri,' To obtain the desired written electron beam pattern of conductive bands 94 on a92 This method is well known in CRT technology. For example, those conductive bands 94 The width and spacing of can be controlled electronically. The conductive band 94 is exposed to an electron beam 90. Can be made to any width by writing multiple closely spaced conductive lines. Ru. Typically, the width of conductive band 94 is period! It is almost half of that. semiconductor 9 The duration of the conductive band 94 of the electron beam pattern written in For a single scan, it is one lifetime time of semiconductor excess carriers, and the same pattern If the file is written many times, it becomes infinitely long. The duration of this conductive band is time, so that the period r can be changed quickly when desired. (e.g., a few microseconds), high-speed beam steering can be achieved by using cathode ray tube technology. A method is provided for rapidly adjusting the period r of a periodic structure by non-mechanical means. can do.

In a representative embodiment of the invention, as shown in FIGS. 26 and 27, a dielectric The body waveguide 28' is an integral part of the cathode ray tube 85 and is sealed with a vacuum seal 91. 86 surface plates are formed. For this embodiment of the invention, a dielectric conductor The material of the wave tube 26 is combined with the rest of the vacuum tube 86 to form a vacuum seal 91. It should be compatible with the amount. Preferred materials for this waveguide 28' are glass, quartz, acid Ceramics such as aluminum oxide, or other low-loss dielectrics including boron It is an electric body.

In FIGS. 26 and 27, the dielectric waveguide 28'' is connected to the surface of the vacuum tube 86. , -1-. Alternatively, the vacuum tube 86 may completely surround the waveguide 28'. You can also do it.

For example, a typical surface plate for CRT such as glass (Figs. 26 and 27) (not shown) on the side of the waveguide opposite the tunable periodic structure 92. 28' and can be spaced apart from and substantially parallel to it. The radiation beam 82 is It will propagate through this surface plate.

Semiconductor 92 is typically a 1-micron layer of material such as silicon or gallium arsenide. The thin film is an order of magnitude thicker and is positioned at an optimal distance from the dielectric waveguide 28'. must be supported in some way. The invention shown in FIGS. 26 and 27 In one embodiment, the support 93 can be a thin glass layer on which the semiconductor A thin body film 92 is deposited on the side of the support opposite waveguide 28'. This support 93 is shown attached to the wall of vacuum tube 86. Or again, this A support 93 can be attached to the waveguide 28°. The support 93 is a vacuum To ensure rigidity at the location where it is attached to the wall of the tube and at the location around the edge of the semiconductor 92. It can be designed thicker to form a screen frame. However, the main On the region, the support 93 should be thin, thereby increasing the conductivity within the semiconductor 92. Band 94 can have the effect of influencing the waveguide beam 4if ( L2 and support 93 do not act as a coupled waveguide and transmit microwave energy. to avoid deflecting energy away from the main dielectric waveguide 28'.

As previously discussed, the waveguide 28' and the tunable periodic structure or semiconductor 92 of FIG. The nominal spacing between (ω in Figure 2) is small and for optimal antenna performance is on the order of 1 mm. Therefore, the support 93 should be on the order of lrnm thick or less. It is. This is the glass surface of a typical vacuum tube 86 as a support 93 for a semiconductor 92. Eliminate the use of plates. As mentioned earlier, as the surface plate of the vacuum tube 86 The dielectric waveguide 28, which acts as a dielectric, can be made of glass or other materials. 0 An important design consideration is that the material of the support 93 in the area of the semiconductor 92 is For performance, it should have a lower dielectric constant than waveguide 28'. . Therefore, if the waveguide 28' is glass, the support 93 on the semiconductor 92 area The material can be porous glass or air-foamed glass, which has a lower dielectric constant than solid glass. It can be made from

For a thin adjustable periodic structure 83 as shown in FIG. There is a supplementary beam 82''. In FIGS. 26 and 27, the outside of the vacuum tube 86 The walls of the can be coated with microwave beam absorbing or reflective materials, which Therefore, the power of the beam 82 at angle θ can be maximized.

An advantage of the embodiment of the invention based on CRT technology shown in FIGS. 26 and 27 is that The amount of power in the beam 1182 (emitted or received by the wave tube 28') is transferred to the semiconductor 92. can be controlled by the amount of conductivity of the band 94. For example, in the electron gun 88 By controlling the power supplied, the conductivity of these bands 94 can be varied. (However, the relationship between power and conductivity is not linear.) Or again, The conductivity of the band 94 is written with the electron beam 90 for a single conductive band 94. 9 In addition, the central bar of the periodicity pattern can be controlled by the number of closely spaced lines. The band can be written more strongly than the band at the edge of the pattern, and it 95: Gives a shadow to the excitation amplitude gradual decrease and side rope control of the radiation pattern. be able to,.

The above-described concept of controlling beam power (emitted or received) can be applied to other embodiments of the invention, i.e. In other words, photoconductors and light are used to guide periodic structures that can be adjusted by controlling the intensity of the light source. It can also be applied to embodiments forming conductive bands (for example, FIGS. 18 and 18). The light source 61 in Fig. 19, the laser light source 90 in Figs. 21 and 22 - the 23rd [3 laser] The photodiode 78).

The various embodiments of the invention described above constitute preferred embodiments of the invention; Many others are possible.

It is not intended herein to describe all possible equivalent forms and details of the invention. do not have. The terminology used herein is merely descriptive, not limiting, and is subject to various changes. It is understood that changes may be made without departing from the spirit and scope of the invention. Should be.

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Claims (38)

[Claims] (1) A directional antenna system that is elongated dielectric waveguide means for transmitting and/or receiving magnetic energy; a plurality of spaced apart longitudinal regions adjacent to and substantially parallel to the waveguide means; adjustable means having a conductive portion of; c) varying the spacing between the conductive parts over a continuous range and control means for determining the directional characteristics of the beam; A directional antenna system consisting of: (2) In the antenna system according to claim 1, the conductive portion is An antenna system characterized by being substantially evenly spaced. (3) In the antenna system according to claim 1, the control means: characterized by acting to determine the direction of maximum or minimum radiation or reception sensitivity; antenna system. (4) In the antenna system according to claim 1, the control means: and varying the distance between at least some of said electrically conductive portions and said waveguide means. An antenna system characterized by: (5) In the antenna system according to claim 4, the control means: The apparatus is operative to control the shape of a radiation pattern of the system. antenna system. (6) The antenna system according to claim 1, wherein the adjustable means characterized by, consisting of a conductive cylindrical helix of substantially round wire on a cylindrical core antenna system. (7) The antenna system according to claim 6, wherein the conductive cylindrical One portion of each turn of the helix is formed by a solid layer adjacent to and generally parallel to the dielectric waveguide. An antenna system characterized in that it consists of a substantially flat surface. (8) The antenna system according to claim 1, wherein the adjustable means is a conductive screw of a rectangular turn of wire of rectangular cross section on a metal wire of rectangular cross section. An antenna system characterized by comprising a spiral. (9) In the antenna system according to claim 6, the control means: The spiral thus varies the length of the intervals between corresponding points on its successive turns An antenna system comprising means for. (10) The antenna system according to claim 1, wherein the adjustable hand The step comprises at least an outer folded portion of a bellows-like flexible member; The outer edge of the carious member forms the electrically conductive spaced apart portion. antenna system. (11) In the antenna system according to claim 10, the control means selectively expands and contracts the flexible member so that the conductive portion of the outer edge An antenna system comprising means for varying said spacing. Mu. (12) The antenna system according to claim 1, wherein the adjustable hand the step comprises a bellows, the outer edge of which forms said conductive spaced-apart portion; Features an antenna system. (13) In the antenna system according to claim 12, the control means selectively expands and contracts the bellows so that the spacing between the conductive portions of the outer edges An antenna system comprising means for varying the distance. (14) The antenna system according to claim 13, wherein the bellows is The means for selectively expanding and contracting the fluid in the bellows and the fluid in the bellows. An antenna system comprising: means for changing pressure. (15) In the antenna system according to claim 1, the adjustable hand Antenna system characterized in that the stages consist of a kinematic chain. (16) In the antenna system according to claim 15, the motion check is characterized by consisting of multiple isopod drag links (telescoping links). antenna system. (17) In the antenna system according to claim 16, the conductive portion The minutes are connected to said drag link at approximately evenly spaced intervals. An antenna system characterized by: (18) In the antenna system according to claim 17, the control means selectively expands and contracts the drag link and thus reduces the spacing between the conductive portions. An antenna system comprising means for changing. (19) In the antenna system according to claim 1, the adjustable hand The step is characterized in that it consists of a rotatable externally threaded cylindrical member. antenna system. (20) In the antenna system according to claim 19, the conductive portion The portion is internally threaded to match the external threading of the cylindrical member. an antenna comprising corresponding surfaces of a plurality of substantially identical polyhedrons. ·system. (21) In the antenna system according to claim 20, the polyhedron is , evenly spaced along the cylindrical member in threaded engagement with the cylindrical member. the polyhedron while allowing movement of the polyhedron along the cylindrical member. The anchor is restrained by a guide member for preventing rotation of the anchor. tena system. (22) In the antenna system according to claim 21, the cylindrical portion The first polyhedron is not movable along the material, and the next (second) polyhedron has a unit length. an adjacent (first) threaded portion of said cylindrical member having x threads per round; and the next (third) polyhedron has 2x threads per unit negative attached to the next adjacent (second) threaded section of the cylindrical member, and so on. The last (nth) polyhedron has (n-1)x threads per unit length. attached to the last ((n-1)th) threaded part of the cylindrical member having An antenna system characterized by: (23) In the antenna system according to claim 1, the adjustable hand The step shall consist of means for producing spaced lines of conductive ink on the non-conductive chip. An antenna system featuring: (24) In the antenna system according to claim 23, the conductive ink Said means for generating a line of separation includes a high speed jet printer and said jet - means for moving the non-conductive tape under the printer. Antenna system with special features. (25) In the antenna system according to claim 24, the non-conductive Said means for moving the tape includes a supply spool and a take-up spool, and said means for moving the tape. and means for rotating a take-up spool. stem. (26) In the antenna system according to claim 25, the control means is the speed of rotation of the take-up spool and therefore the speed of the non-conductive tape and comprising means for controlling said spacing of said lines of conductive ink thereon; Features an antenna system. (27) In the antenna system according to claim 1, the adjustable hand the steps are evenly spaced over a portion of the tape that is longer than the dielectric waveguide and A tape with conductive lines of slightly different period in adjacent parts of said tape said control means directs said portion of tape between a supply spool and a take-up spool. an antenna system comprising: means for moving to and from the antenna system; Mu. (28) In the antenna system according to claim 27, the control means Said dielectric waveguide selected portions of said tape with evenly spaced conductive lines An antenna system comprising means for positioning adjacent to a tube. Tem. (29) In the antenna system according to claim 27, the conductive layer An antenna system characterized in that the ink is a conductive ink on a non-conductive tape. stem. (30) The antenna system according to claim 27, wherein the conductive layer The ins are electrically conductive materials separated by slots within the tape. Antenna system with special features. (31) In the antenna system according to claim 1, the adjustable hand The step consists of a photoconductive surface that is aligned with the axis of the dielectric waveguide. Through a transparent, closely spaced and overlapping standard grid with lines that are parallel in nature Illuminated by directed light, the grating is fixed at one end and connected to each other at the other end. the waveguide is free to move and oriented substantially perpendicular to the axis of the waveguide; An antenna system characterized by forming a vignetted moiré fringe band. (32) In the antenna system according to claim 31, the control means is the angle between the grating lines on each said grating, and therefore the spacing of the moire fringe bands, and the photoconductive surface by controlling the spacing of bands of light impinging on the photoconductive surface; An antenna system characterized in that it generates conductive portions that are evenly spaced apart from each other. . (33) In the antenna system according to claim 1, the adjustable hand The stage comprises a photoconductive surface, a light source, and the control means directs the light from the light source. means for providing electrically conductive portions of said surface and controlling the spacing thereof. An antenna system characterized by. (34) In the antenna system according to claim 33, the conductive portion The means for controlling the interval of minutes includes an acoustic - An antenna system characterized in that it consists of optical means. (35) The antenna system according to claim 34, wherein the acoustic-optical The means for varying the frequency of the optical means has an adjustable differential frequency. comprising drive signal means for providing a plurality of separated discrete frequencies; Antenna system with special features. (36) The antenna system according to claim 35, wherein the acoustic-optical The means for varying the frequency of the optical means has an adjustable differential frequency. from a drive signal means for providing a sequence of multiple discrete frequencies that are separated; An antenna system characterized by: (37) In the antenna system according to claim 33, the light source: said conductive portion comprising a laser diode array means and a focusing optics means; The means for controlling the spacing of selectively selects appropriate diodes in the array. an antenna system comprising computer means for activating Tem. (38) In the antenna system according to claim 1, the adjustable hand The stage consists of a semiconductor surface in a vacuum tube, a source of an electron beam, said control means comprising: deflecting the electron beam from the source to provide an electrically conductive portion of the surface; An antenna system comprising means for controlling the spacing thereof. .