TWI634701B - Dynamic polarization and coupling control for a steerable cylindrically fed holographic antenna - Google Patents

Abstract

Apparatus for a cylindrical feed antenna and methods of using the same are disclosed herein. In one embodiment, the antenna includes an antenna feed to input a cylindrical feed wave and a tunable slot array coupled to the antenna feed.

Description

Dynamic polarization and coupling control technique for steerable cylindrical feed hologram antenna priority

This patent application claims the provisional patent application No. 61/941,801, entitled "Polarization and Coupling Control of Self-Cylinder Feeding Holographic Antenna" on February 19, 2014 and the corresponding provisional patent application No. 62 /012,897, entitled "Supermaterial Antenna for Communication Satellite Ground Stations", the priority date of the application date of 2014, which is hereby incorporated by reference.

Field of invention

Embodiments of the invention relate to the field of antennas; more specifically, embodiments of the invention relate to cylindrical feedthrough antennas.

Background of the invention

Using a printed circuit board (PCB)-based approach, Thinkom products achieve double circular polarization in the Ka-band, usually using a variable tilt lateral residual or "VICTS" approach, with two types of mechanical rotation . The first type rotates the other array relative to one array, and the second type rotates both in azimuthal rotation. The main limitation is the scanning range (elevation angle 20 degrees to 70 degrees, not Can be side-to-side) and beam performance (occasionally limited to reception).

Ando et al., "Radline Slot Antennas for 12 GHz DBS Satellite Receiving" and Yuan et al., "Design and Experiment of Novel Radial Trunk Antennas for High Power Microwave Applications" discuss various antennas. The limitation of the antennas described in these two articles is that the beam is formed only at one static angle. The feed structure described in the article is a folded double layer where the first layer receives the pin feed and outwardly emits a signal to the edge, bends the signal upward to the top layer, and then the top layer is energized and fixed from the periphery to the center. Slotted. Slotting is typically oriented as an orthogonal pair, obtaining a fixed circular polarization of the emission mode, and the opposite side being the receiving mode. Finally, the absorber terminates any remaining energy.

"The scalar and tensor full-image artificial impedance surface" by Fong, Coburn, Ottusch, Visher, Sievenpiper. Although Sievenpiper has shown how to achieve a dynamic scan antenna, the polarization fidelity remains questionable during the scan. The reason for this is that the required polarization control depends on the tensor impedance required at each of the radiating elements. This is most simply achieved by one-by-one component rotation. However, as the antenna scans, the polarization at each element changes, and thus the required rotation also changes. Since these components are fixed and cannot be rotated dynamically, there is no way to scan and maintain polarization control.

In order to achieve an industry standard approach to beam-controlled antennas with polarization control, mechanically rotating disks or some type of mechanically moving combined electron beam manipulation are typically used. The most expensive option category is the all-phase array antenna. The disc can receive multiple polarizations at the same time, but requires a balance ring to scan. More recently, combining mechanical movements on one axis with electronic scanning on orthogonal axes results in a structure with a high aspect ratio that requires less volume but sacrifices beam efficiency. Capable or dynamic polarization control, such as Thinkom products.

Prior art approaches use a waveguide and beam splitter feed structure to feed the antenna. However, the waveguide designs have near-side impedance swings (a band gap created by the 1-wavelength periodic structure); are required to be combined with dissimilar CTE; have ohmic losses associated with the feed structure; and/or thousands of passes The holes extend to the ground plane.

Summary of invention

Apparatus for a cylindrical feed antenna and methods of using the same are disclosed herein. In one embodiment, the antenna includes an antenna feed to input a cylindrical feed wave and a tunable trough array coupled to the antenna feed.

201, 215‧‧‧ coaxial pins

202‧‧‧ Ground plane

203, 1203, 2003‧‧‧ gap conductor

204, 1204, 2004‧‧‧ spacers, spacers

205, 212, 1702, 2005‧‧‧ dielectric layer

206, 216, 1801‧‧‧RF array

207, 208‧‧‧ side

209‧‧‧ Terminal

210, 211‧‧‧ ground plane

213, 214‧‧‧RF absorber

2001, 2002‧‧‧

300, 405a, 1710‧‧ ‧ patches

302, 403a‧‧‧ slotting

303‧‧‧Liquid Crystal (LC)

402, 1802‧‧‧ dielectric

403, 1703‧‧ ‧ iris board, circuit board

403b‧‧‧round opening

404, 1704‧‧‧ liquid crystal substrate layer

405‧‧‧ Patch Plate

1701‧‧‧ Conductive basal or bottom layer

1705‧‧‧ glass layer

1800‧‧‧ coaxial feed

1900‧‧‧ Ring

1901, 1905‧‧‧ arrows

1903‧‧‧ Phase wavefront

1904‧‧‧TEM wave

A, B‧‧‧ height

The invention will be more fully understood from the following detailed description of the embodiments of the invention.

Figure 1 illustrates a top view of one embodiment of a coaxial feed to provide a cylindrical wave feed.

2A and 2B illustrate side views of an embodiment of a cylindrical feed antenna structure.

Figure 3 illustrates a top view of one embodiment of a slotted coupling chip antenna or diffuser.

Figure 4 illustrates a side view of a slotted feed-in chip antenna belonging to a component of a cylindrical feed antenna system.

Figure 5 illustrates an embodiment of a dielectric material that emits a feed wave thereto.

Figure 6 illustrates an embodiment of an iris plate showing the slots and their alignment.

Figure 7 illustrates the manner in which the alignment of an iris/patch combination is determined.

Figure 8 illustrates the iris grouping into two sets, the first set rotated -45 degrees relative to the power feed vector, and the second set rotated +45 degrees relative to the power feed vector.

Figure 9 illustrates an embodiment of a patch panel.

Figure 10 illustrates an embodiment of an element having the patch of Figure 9 that is closed when determined at the operating frequency.

Figure 11 illustrates an embodiment of an element having the patch of Figure 9 that is activated upon decision of the operating frequency.

Figure 12 illustrates the results of full wave modeling, showing the electric field response to one of the switch control/modulation patterns with respect to the elements of Figures 10 and 11.

Figure 13 illustrates beam formation using one embodiment of a cylindrical feed antenna.

Figures 14A and 14B illustrate patches and slots configured in a honeycomb style.

15A-C illustrate a patch configured as a loop and an associated slot to create a radial layout, a phased control pattern, and resulting antenna response.

16A and 16B illustrate right-handed circular polarization and left-handed circular polarization, respectively.

Figure 17 illustrates a portion of a cylindrical feed antenna including a glass layer containing one of the patches.

Figure 18 illustrates a linear decrease in a dielectric.

Figure 19A illustrates an embodiment of a reference wave.

Fig. 19B illustrates a generated object wave.

Figure 19C illustrates one embodiment of the resulting sinusoidal modulation pattern.

Figure 20 illustrates another antenna embodiment wherein the sides each include a first order such that a traveling wave is emitted from the bottom layer to the top layer.

Detailed description of the preferred embodiment

Embodiments of the present invention include an antenna design architecture that feeds an antenna from a center point with an excitation (feeding wave) that expands outwardly from the feed point in a cylindrical or concentric manner. The antenna functions by arranging a plurality of cylindrical feed sub-aperture antennas (chip antennas) with feed waves. In an alternate embodiment, the antenna is fed inwardly from the periphery rather than from the center. This is helpful because it counteracts the amplitude excitation attenuation caused by the aperture scattering energy. The appearance of scattering is similar in both directions, but the natural decreasing cone caused by energy focusing as the feeding wave travels inward from the periphery counterbalances the decreasing cone caused by intentional scattering.

Embodiments of the present invention include a holographic antenna that is typically required to achieve a holographic density based on multiplication, and to fill the aperture with a set of two orthogonal elements. In one embodiment, a set of components is linearly oriented +45 degrees with respect to the feed wave, and the second set of components is oriented at -45 degrees relative to the feed wave. The two types are illuminated by the same feed wave. In one form, the feed wave is a parallel plate model fed by a coaxial pin.

In the following detailed description, numerous details are set forth to provide a more thorough explanation of the invention. It will be appreciated by those skilled in the art that the present invention may be practiced without the specific details. In other instances, well-known structures and devices are shown in block diagrams and not in detail, so as not to obscure the invention.

Some of the sections in the following detailed description are presented in terms of algorithms and symbolic representations that operate on the data bits in computer memory. These algorithmic descriptions and representations are the most effective means by which data processing professionals can pass on the essence of their work to other skilled practitioners. In summary, an algorithm must be recognized as a result of a series of steps leading to a desired result. These steps are steps that require entity manipulation of the entity quantity. Typically, but not necessarily, such quantities are in the form of electrical or magnetic signals that can be stored, transferred, combined, compared, and otherwise manipulated. It has been proven that, for common reasons, such signals may occasionally be referred to as bits, values, elements, symbols, characters, terms, numbers, and the like.

It is to be borne in mind, however, that all such similar terms are associated with the appropriate quantities and are applied to the number of the convenience. Unless otherwise stated in the following discussion, it is necessary to understand that the use of terms such as "processing" or "operation" or "calculation" or "decision" or "display" in the detailed description of the full text refers to a computer system or similar The operation and processing of the electronic computing device, which is represented in the scratchpad of the computer system and the data represented by the physical (electronic) amount, manipulated and converted into a memory or a temporary storage device or other in the computer system Such information storage, transmission or display devices are similarly represented internally as other quantities of material.

Overview of embodiments of antenna systems

An embodiment of a metamaterial antenna system for a communication satellite ground station is described. In one embodiment, the antenna system is a component or a subsystem of a satellite ground station operating on a mobile platform (eg, aeronautical, marine, terrestrial, etc.) using a commercial commercial satellite communication Ka- Band frequency or Ku-band frequency operation. Note that embodiments of the antenna system can also be used for ground stations that are not on the mobile platform (eg, fixed or transportable ground stations).

In one embodiment, the antenna system uses surface scattering metamaterial technology to form and manipulate beams transmitted and received via separate antennas. In one embodiment, as opposed to antenna systems that employ digital signal processing to electrically form and manipulate beams, such as phased array antennas, the antenna systems are analog systems.

In one embodiment, the antenna system comprises three functional subsystems: (1) a wave propagation structure consisting of a cylindrical wave feed architecture; (2) an array of wave scattering metamaterial unit cells; and (3) A control structure commands the use of a holographic principle to form an adjustable radial field (beam) from the metamaterial scattering element.

Wave propagation structure embodiment

Figure 1 illustrates a top view of one embodiment of a coaxial feed to provide a cylindrical wave feed. Referring to Figure 1, the coaxial feed includes a center conductor and an outer conductor. In one embodiment, the cylindrical wave feed-in architecture feeds the antenna from a center point with an excitation that expands outwardly from the feed point in a cylindrical shape. In other words, a cylindrical feed antenna produces a concentric feed wave that travels outward. Even so, the cylindrical feed antenna surrounding the cylindrical feed can be circular, square or any shape. In another embodiment, a cylindrical feed antenna produces a feed wave that travels inward. In this case, the feed wave is largely from a circular structure.

Figure 2A illustrates a side view of one embodiment of a cylindrical feed antenna structure. The antenna uses a two-layer feed structure (two layers of a feed structure) Produces waves that travel inward. In one embodiment, the antenna includes a circular shape, but is not necessary. In other words, a non-circular inwardly traveling structure can be used. In one embodiment, the antenna structure of FIG. 2A includes the coaxial feed of FIG.

Referring to Figure 2A, a coaxial pin 201 is used to excite the field at a lower level of the antenna. In one embodiment, the coaxial pin 201 is a convenient 50 ohm (Ω) coaxial pin. The coaxial pin 201 is coupled (e.g., bolted) to the bottom of the antenna structure, the bottom being a conductive ground plane 202.

Separated from the conductive ground plane 202 is a gap conductor 203, which is an inner conductor. In one embodiment, the conductive ground plane 202 and the gap conductor 203 are parallel to each other. In one embodiment, the distance between the ground plane 202 and the gap conductor 203 is between 0.1 and 0.15 吋. In another embodiment, the distance may be λ/2, where λ is the operating frequency, the wavelength of the traveling wave.

The ground plane 202 is separated from the gap conductor 203 by a spacer 204. In one embodiment, the spacer 204 is a foam or air spacer. In one embodiment, the spacer 204 comprises a plastic spacer.

A dielectric layer 205 is placed on top of the gap conductor 203. In one embodiment, the dielectric layer 205 is a plastic. Figure 5 illustrates an embodiment of a dielectric material in which a feed wave is emitted. The purpose of the dielectric layer 205 is to slow the transitional wave relative to the free space velocity. In one embodiment, the dielectric layer 205 slows the transition wave by up to 30% relative to the free space velocity. In one embodiment, the refractive index suitable for beamforming ranges from 1.2 to 1.8, as defined herein, the free space has a refractive index equal to one. Other dielectric spacer materials such as plastic can be used to achieve this effect. Note that materials other than plastic can also be used as long as they achieve the desired wave slowing effect. In addition, it can be used A material having a dispersed structure acts as a dielectric 205, such as a periodic sub-wavelength metal structure that can be defined by cutting or photolithography.

The RF array 206 is on top of the dielectric 205. In one embodiment, the distance between the gap conductor 203 and the RF array 206 is between 0.1 and 0.15 吋. In another embodiment, the distance may be λ _eff /2 where λ _eff is the effective wavelength of the design frequency within the medium.

The antenna includes sides 207 and 208. The sides 207 and 208 are curved so that the traveling wave from one of the coaxial pins 201 is transmitted through the reflection and propagates from the lower region (spacer layer) of the gap conductor 203 to the region above the gap conductor 203 (the dielectric layer). In one embodiment, the corners of the sides 207 and 208 are at an angle of 45 degrees. In an alternate embodiment, sides 207 and 208 are replaced by a continuous radius to achieve reflection. Although Figure 2A shows a curved side with a 45 degree angle, other angles can be used to enable signal transmission from lower level feeds to higher level feeds. In other words, assuming that the effective wavelength at the lower feed is typically different from the effective wavelength at the higher feed, a slight deviation from the ideal 45 degree angle can be used to assist in the transmission from the lower level feed to the higher level feed. For example, in another embodiment, the 45 degree angle can be replaced by a single order, such as shown in FIG. Referring to Figure 20, steps 2001 and 2002 show a surrounding dielectric layer 2005, a gap conductor 2003, and a spacer layer 2004 on one end of the antenna. The same two orders are on the other end of the layers.

In operation, when a feed wave is fed from the coaxial pin 201, the wave travels concentrically from the coaxial pin 201 in the region between the ground plane 202 and the gap conductor 203. The concentric output waves are reflected by sides 207 and 208 and travel inwardly between the gap conductor 203 and RF array 206. Reflection from the edge of the circular perimeter causes the waves to remain in phase (i.e., belong to the same phase reflection). The transition wave is slowed down by the dielectric layer 205. At this point, the transition wave begins with component interaction and excitation in the RF array 206 to achieve the desired scatter.

To terminate the transition wave, a terminal 209 is included in the geometric center of the antenna. In one embodiment, terminal 209 includes a pin terminal (eg, a 50 ohm pin). In another embodiment, terminal 209 includes an RF absorber that terminates unused energy to prevent the unused energy from being reflected back through the feed structure of the antenna. These can be used at the top of the RF array 206.

Figure 2B illustrates another embodiment of the antenna system having an output wave. Referring to FIG. 2B, the two ground planes 210 and 211 are substantially parallel to each other with a dielectric layer 212 (eg, a plastic layer, etc.) between the ground planes 210 and 211. RF absorbers 213 and 214 (e.g., resistors) couple the two ground planes 210 and 211 together. A coaxial pin 215 (e.g., 50 ohms) is fed to the antenna. An RF array 216 is attached on top of the dielectric layer 212.

In operation, a feed wave is fed via coaxial pin 215 and travels concentrically outwardly and interacts with components of RF array 216.

The cylindrical feed in both the antennas of Figures 2A and 2B improves the service angle of the antenna. Substituting a positive or negative 45 degree azimuth (±45° Az) and a positive or negative 25 degree elevation (±25° El) service angle, in one embodiment, the antenna system has 75 from all of the line of sight in all directions Degree of service (75°). Like any beamforming antenna that contains many individual transmitters, the total antenna gain is dependent on the gain of the constituent elements, which in turn are angled Dependency. When a common transmit element is used, the total antenna gain is typically reduced as the beam is further directed away from the line of sight. A significant gain degradation of approximately 6 decibels (dB) is expected when deviating from the line of sight by 75 degrees.

Embodiments having a cylindrical feed antenna solve one or more problems. These solutions include dynamically simplifying the feed structure compared to antennas fed in a cooperative divider network, and thus reducing the total required antenna and antenna feed volume; using coarser control (one way to two Carry control) maintains high beam performance while reducing sensitivity to manufacturing errors and control errors; a superior sidelobe pattern is obtained over linear feeds because the cylindrically oriented feed wave results in the far field Space-diversity side lobes; again allow polarization to be dynamic, including allowing left-hand circular polarization, right-hand circular polarization, and linear polarization without the need for a polarizer.

Array of wave scattering elements

The RF array 206 of Figure 2A and the RF array 216 of Figure 2B include a wave scattering subsystem comprising a set of patch antennas (i.e., diffusers) as one of the radiators. The set of chip antennas comprises an array of scattering metamaterial elements.

In one embodiment, each of the scattering elements in the antenna system is a portion of a unit cell consisting of a lower conductor, a dielectric substrate, and an upper conductor embedded with a complementary electrical inductor-capacitor. A resonator ("complementary electrical LC" or "CELC") that is etched or deposited on the upper conductor.

In one embodiment, a liquid crystal (LC) is implanted into the gap surrounding the scattering element. The liquid crystal is encapsulated in each unit cell, and the lower conductor and the upper conductor connected to a patch are separated from a slot. liquid The crystal has a dielectric coefficient which is a function of the alignment of the molecules constituting the liquid crystal, and the alignment of the molecules (and thus the dielectric constant) can be controlled by adjusting the bias voltage across the liquid crystal. Using this property, the liquid crystal is transmitted as energy from the guided wave to the on/off switch of the CELC. When the switch is on, the CELC emits electromagnetic waves similar to an electrical small dipole antenna.

Controlling the thickness of the LC increases the beam switching speed. A 50% (50%) reduction in the gap between the lower conductor and the upper conductor (thickness of the liquid crystal) results in a fourfold increase in speed. In another embodiment, the thickness of the liquid crystal results in a beam switching speed of about 14 milliseconds (14 ms). In one embodiment, the liquid crystal is doped in a manner well known in the art to improve responsiveness and thus meets the requirements of 7 milliseconds (7 ms).

The CELC is responsive to a magnetic field that is applied parallel to the plane of the CELC element and perpendicular to the CELC gap complement. When a voltage is applied to the liquid crystal in the cell of the metamaterial scattering unit, the magnetic field component of the guided wave induces magnetic excitation of the CELC, which in turn produces an electromagnetic wave of the same frequency as the guided wave.

The phase of the electromagnetic wave generated by a single CELC can be selected by the location of the CELC on the vector of the guided wave. Each unit cell produces a wave that is in phase with the waveguide parallel to the CELC. Since the CELC system is smaller than the wavelength, the output wave has the same phase as the phase of the guided wave when it passes under the CELC.

In one embodiment, the cylindrical feed geometry of such an antenna system allows the CELC component to be positioned at an angle of 45 degrees (45[deg.]) to the vector of the wave in the wave feed. The location of these components allows control of such components The polarization of the free space wave generated or received by the elements. In one embodiment, the CELC is configured with an inter-element spacing that is less than the free-space wavelength of the operating frequency of the antenna. For example, if there are 4 scattering elements per wavelength, then the elements in the 30 GHz transmit antenna will be about 2.5 mm (i.e., 1/4 of a 10 mm free space wavelength of 30 GHz).

In one embodiment, the CELCs are implemented with a chip antenna that includes a patch that is co-located over a slot and has a liquid crystal therebetween. In this regard, the metamaterial antenna is used as a slotted (scattering) waveguide. Using a slotted waveguide, the phase of the output wave depends on the position of the slot relative to the guided wave.

Figure 3 illustrates a top view of one embodiment of a chip antenna or scattering element. Referring to FIG. 3, the patch antenna includes a patch 301 co-located over a slot 302 with a liquid crystal (LC) 303 between the patch 301 and the slot 302.

Figure 4 illustrates a side view of a one-piece antenna belonging to a component of a cylindrical feed antenna system. Referring to Figure 4, the patch antenna is mounted over a dielectric 402 (e.g., a plastic insert, etc.) over the gap conductor 203 (or ground conductor, such as the antenna of Figure 2B) of Figure 2A.

An iris plate 403 is a ground plane (conductor) having a plurality of slots, such as a slot 403a above and above the dielectric 402. A slot can be referred to herein as an iris. In one embodiment, the grooving in the iris plate 403 is created by etching. Note that in one embodiment, the highest density of the cells that are slotted or slotted to their component is λ/2. In one embodiment, the slot/cell density is λ/3 (ie, there are 3 cells per λ). Note that other densities of the unit cell can be used.

A patch plate 405 containing a plurality of patches, such as patch 405a, is positioned over the iris plate 403, separated by an intermediate dielectric layer. Each of the patches, such as patch 405a, is co-located with one of the slots in iris plate 403. In one embodiment, the intermediate dielectric layer between the iris plate 403 and the patch plate 405 is a liquid crystal base layer 404. The liquid crystal acts as a dielectric layer between the respective patches and the slots therebetween. Note that a base layer other than liquid crystal can be used.

In one embodiment, the patch panel 405 includes a printed circuit board (PCB), each patch containing metal on the PCB where the metal surrounding the patch has been removed.

In one embodiment, the patch panel 405 includes through-holes for each patch that are on opposite sides of the side of the patch panel that face the co-located slot of the patch. The vias are used to connect one or more traces to a patch to provide a voltage to the patch. In one embodiment, the matrix driver is used to apply a voltage to the patch to control it. This voltage is used to tune or de-tune individual components to achieve beamforming.

In one embodiment, the patch may be deposited on a glass layer, such as a glass typically used in liquid crystal displays (LCDs, such as Corning Eagle glass), rather than using a circuit patch board. Figure 17 illustrates a portion of a cylindrical feed antenna including a glass layer containing one of the patches. Referring to FIG. 17, the antenna includes a conductive base layer or bottom layer 1701, a dielectric layer 1702 (eg, plastic), a slotted iris plate 1703 (eg, a circuit board), a liquid crystal base layer 1704, and a glass layer 1705 including a patch 1710. . In one embodiment, the patch 1710 has a rectangular shape. In one embodiment, the slots and patches are positioned in rows and rows, and the alignment of the patches is the same for each column or behavior, and such The alignment of the co-located slots is the same orientation relative to each other for the columns or rows.

In one embodiment, a cover (eg, a radome) covers the top of the patch antenna stack to provide protection.

FIG. 6 illustrates an embodiment of an iris plate 403. This is the conductor under the CELC. Referring to Figure 6, the iris plate includes an array of slots. In one embodiment, the individual slots are oriented at +45 degrees or -45 degrees with respect to the feed wave at the center of the impact slot. In other words, the layout pattern of the scattering element (CELC) is arranged at ±45 degrees with respect to the vector of the wave. Below each of the slots is a circular opening 403b which is generally another slot. The slot is attached to the top of the iris plate, and a circular opening or elliptical opening is attached to the bottom of the iris plate. Note that these openings are selective and may have a depth of about 0.001 吋 or 25 mm.

A slotted array is tunably oriented to load. Each slot is tuned by a switch that is tuned to provide a desired scatter at the operating frequency of the antenna (i.e., tuned to operate at a given frequency).

Figure 7 illustrates the manner in which the alignment of an iris (grooving)/patch combination is determined. Referring to Figure 7, the letter A indicates a solid black arrow indicating the power feed vector from the cylindrical feed position to the center of a component. The letter B indicates that the dotted orthogonal line shows the vertical axis with respect to "A", and the letter C indicates that the dotted rectangle surrounds the 45 degree groove with respect to "B".

Figure 8 illustrates an iris (grooving) grouped into two sets, the first set rotated -45 degrees with respect to the power feed vector, and the second set rotated +45 degrees relative to the power feed vector. Referring to Figure 8, Group A includes a slot that rotates -45 degrees with respect to the feed vector, and Group B includes a slot that rotates +45 with respect to the feed vector. degree.

Note that the indication of the overall coordinate system is not important, so that the rotation of the negative and positive angles is only necessary when describing the relative rotation of the elements relative to each other and to the direction of the feed wave. In order to produce circular polarization from the two sets of linear polarization elements, the elements of the two sets are perpendicular to each other and have equal amplitude excitations at the same time. Two desired characteristics are achieved by rotating ±45 degrees at a time relative to the feed wave excitation. A set rotates 0 degrees and another set rotates 90 degrees to achieve a vertical target, but a non-equal amplitude excitation target.

FIG. 9 illustrates one embodiment of a patch panel 405. This is the conductor above CELC. Referring to Figure 9, the patch panel includes a rectangular patch covering the slot and completing a linearly polarized patch/grooved resonant pair to be turned off and activated. The pair is turned off and on by applying a voltage to the patch using the controller. The required voltage depends on the liquid crystal mixture to be used, the resulting threshold voltage is required to start tuning the liquid crystal, and the maximum saturation voltage (no higher voltage than this voltage produces any effect, but eventually degrades or shorts through the liquid crystal). In one embodiment, the matrix drive is used to apply a voltage to the patch to control the coupling.

Antenna system control

The control structure has two major components: the antenna system controller including the drive electronics is located below the wave scattering structure, and the matrix drive switching array is dispersed throughout the transmit RF array so as not to interfere with the radiation. In one embodiment, the drive electronics of the antenna system includes a commercial off-the-shelf LCD controller for use in a commercial television facility that adjusts the bias voltage for each of the scattering elements by adjusting the amplitude of the AC bias signal to the component. .

In one embodiment, the controller is controlled using software control electronic circuit. In one embodiment, the control of polarization is the software control portion of the antenna, and the polarization is pre-programmed to match the polarization of signals from satellite services communicating with the ground station, or is pre-programmed to match the satellite The polarization of the receiving antenna on the service.

In one embodiment, the controller also contains a microprocessor to execute the software. The control structure can also incorporate a sensor (including a GPS receiver, a three-axis compass, and an accelerometer) to provide position and alignment information to the processor. Location and alignment information may be provided to the processor by other systems in the ground station and/or may not be part of the antenna system.

More specifically, which components are turned off and which components are turned on when the controller operates. These components are selectively demodulated for frequency operation by applying a voltage. The controller supplies an array of voltage signals to the RF transmit patch to produce a modulation or control pattern. This control pattern causes the components to be activated or deactivated. In one embodiment, the control pattern is similar to a square wave in which the elements along a spiral (LHCP or RHCP) are "on" and the elements away from the spiral are "off" (ie, a binary modulation pattern). In another embodiment, polymorphic control is used in which each element is turned off and activated to an unequal level, more closely related to a square wave, a sine wave control pattern (ie, a sine wave gray tone modulation pattern). Some components are stronger than others, and some are not emitted and some are not. Variable radiation is achieved by applying a specific voltage level that adjusts the liquid crystal dielectric constant to unequal amounts, thereby demodulating the elements in a variable manner and making certain elements more intense than others.

The generation of a focused beam from the element's metamaterial array can be explained by the constructive interference involving destructive interference phenomena. If individual electromagnetic waves have the same phase, then When they meet in free space, they add up (consistent interference); and if they have opposite phases, they cancel out when they meet in free space (destructive interference). If the slots in the slot antenna are positioned such that each successive slot position is at a different distance from the excitation point of the guided wave, the scattered wave from the element will have a different phase than the scattered wave of the previous slot. If the slot spacing is 1/4 of the wavelength, each slot will scatter a wave with a 1/4 phase delay from the previous slot.

Using this array, the number of patterns that can be produced with destructive interference can be increased, so that using the holographic principle, the beam can theoretically point in any direction that is plus or minus 90 degrees (90°) from the line of sight of the antenna array. . Thus, by controlling which metamaterial unit cells are activated or deactivated (ie, by changing which cell is activated and which cells are turned off), the resulting phase stems involve different patterns of destructive interference, and the antenna The wavefront direction can be changed. The time required for the unit cell to be turned on and off determines the speed at which the beam can be switched from one location to another.

Both the polarization and the beam aiming angle are defined by modulation, or the control pattern indicates which components are activated or deactivated. In other words, the frequency of the aiming beam and polarization in a desired manner depends on the control pattern. Since the control pattern is programmable, polarization can be planned for the antenna system. The desired polarization state for most applications is a circle or a line. For a feed wave that feeds in and out of the center, the circularly polarized state includes a helically polarized state, that is, a left-handed circular polarization and a right-handed circular polarization, which are shown in Figures 16A and 16B, respectively. Note that in order to obtain the same beam, the feed direction is switched at the same time (for example, from feed-in to feed-out), alignment or sensing, or spiral modulation pattern reversal. Note that when one of the open and closed elements is given a given spiral pattern resulting in a left-hand or right-hand circular polarization, the direction of the feed wave (ie, the center feed or The edge is also included.

The control pattern for each beam will be stored in the controller or calculated in flight, or some combination thereof. When the antenna control system determines where and where the antenna is located, then the line of sight of the antenna is used to determine where the target satellite is located. The controller then commands one of the individual unit cells in the array to open and close the pattern, which corresponds to a preselected beam pattern for the satellite position in the antenna field of view.

In one embodiment, the antenna system produces a steerable beam for the uplink antenna and a steerable beam for the downlink antenna.

Fig. 10 illustrates an embodiment in which the component having the patch of Fig. 9 is off when the operating frequency is determined, and Fig. 11 illustrates an embodiment in which the component having the patch of Fig. 9 is determined to be on the operating frequency. Figure 12 illustrates the results of full wave modeling showing the electric field response of one of the on and off modulation modes for the components of Figures 10 and 11.

Figure 13 illustrates beamforming. Referring to Figure 13, the interference pattern can be adjusted to provide any antenna emission pattern by identifying an interference pattern corresponding to a selected beam pattern and then adjusting the voltage across the scattering element to produce a holographic principle. a beam. The basic principles of holographic techniques, including the terms "object beam" and "reference beam" commonly used in connection with such principles, are well known. Using a transitional wave as a "reference beam", the RF hologram in the context of forming a desired "object beam" proceeds as follows.

The modulation style is determined as follows. First, a reference wave (beam) is generated, occasionally referred to as a feed wave. Figure 19A illustrates one embodiment of a reference wave. Reference map 19A, ring 1900 is the phase wavefront of the electric field and magnetic field of a reference wave. It has a sine wave time variation. Arrow 1901 illustrates the outward propagation of the reference wave.

In the present embodiment, a TEM wave or a transverse electromagnetic wave travels inward or outward. The direction of propagation is also defined and used in this embodiment to select for propagation from a central feed point. The propagation plane is along the antenna surface.

Generate a wave of objects, occasionally called a bundle of objects. In this embodiment, the object wave is a TEM wave whose orthogonal antenna surface travels in a direction deviating from 30 degrees, and the azimuth angle is set to 0 degrees. Polarization is also defined, and for this embodiment, right-hand circular polarization is selected. Fig. 19B illustrates the generated object wave. Referring to Figure 19B, the phase wavefront 1903 of the electric and magnetic fields of the TEM wave 1904 in propagation is shown. Arrow 1905 is the electric field vector at each phase wavefront, and is represented by an interval of 90 degrees. In this embodiment, it is selected in accordance with right circular polarization.

Interference or modulation pattern = Re{[A]x[B]*}

When a sine wave is multiplied by the conjugate complex of another sine wave and the real part is taken, the resulting modulation pattern is also a sine wave. In space, when the maximum amount of the reference wave is the maximum amount of the body wave (both sine wave time variation), the modulation pattern is the maximum amount, or the strong emission position. In fact, such interference is calculated at each scattering position and depends not only on the position of the element, but also on the polarization of the element and the polarization of the object wave at the position of the element based on its rotation. Figure 19C is an embodiment of the resulting sinusoidal modulation pattern.

Note that it can be further selected to simplify the resulting sine wave gray-shadow modulation pattern into a square wave modulation pattern.

Note that the voltage across the scattering element is controlled by the voltage applied between the patch and the ground plane. In this case, the metal on the top of the iris plate. Chemical.

Other embodiments

In one embodiment, the patch and slot are positioned in a honeycomb pattern. An embodiment of this style is shown in Figures 14A and 14B. Referring to Figures 14A and 14B, the honeycomb structure is shifted left or right by half a component interval every other column, or alternatively, every other row is shifted up or down by half a component interval.

In one embodiment, the patch and the associated slotted system are positioned in a loop to create a radial layout. In this case, the center of the slot is tied to the ring. Figure 15A illustrates one embodiment of a patch positioned in a loop (and its co-located slots). Referring to Figure 15A, the centers of the patches and slots are attached to the loop, and the loops are concentrically positioned relative to the feed or termination points of the antenna array. Note that adjacent slots located in the same ring are oriented approximately 90 degrees relative to each other (as evaluated at their center). More specifically, it is oriented at an angle equal to 90 degrees plus an angular displacement of the ring along the geometric center containing the two elements.

Figure 15B is an illustration of one of the control styles for a slot-based slotted array as depicted in Figure 15A. The resulting near-field and far-field for the 30-degree beam pointed to by the LHCP are shown in Figure 15C, respectively.

In one embodiment, the feed structure is shaped to control coupling to ensure that the power transmitted or scattered across the full 2D aperture is substantially constant. This is achieved by a linear decrease in the thickness of the dielectric, or a similar decrease in the case of a ridge feed into the network, resulting in less coupling near the feed point and more coupling away from the feed point. Linear decrement is used for the feed height. When the travel wave propagates away from the feed point, the smaller volume contains the energy and counteracts the l/r attenuation of the travel wave. As a result, the feed from the scattering of each component remains. A large percentage of the remaining energy. This point is important for producing a uniform amplitude excitation across the aperture. For non-radially symmetric feed structures, such as those having a square or rectangular outer dimension, such decrement can be applied in a non-radially symmetric manner to cause the scattering power across the aperture to be roughly constant. The compensation technique requires different tuning of the components based on how far the components in the array are from the feed point.

One embodiment of the decrement is to use a dielectric in the shape of a Maxwell fisheye lens to produce an inverse increase in emission intensity to counteract l/r attenuation.

Figure 18 illustrates the linear decrease of the dielectric. Referring to Figure 18, a decreasing dielectric 1802 is shown having a coaxial feed 1800 to provide a concentric feed wave to perform the components (patch/iris pair) of the RF array 1801. The height of the dielectric 1802 (e.g., plastic) decreases from a maximum height near the coaxial feed 1800 to a lower height that is farthest from the point of the coaxial feed 1800. For example, the height B is greater than the height A because the height B is closer to the coaxial feed 1800.

With this in mind, in one embodiment, the dielectric forms a non-radially symmetric shape to focus energy where needed. For example, taking a square antenna fed from a single feed point as described herein, the path length from the center to the square is 1.4 times longer than the path length from the center to the center of the square side. Therefore, comparing the four intermediate points on the four sides of the square requires more energy to focus toward the four corners, and the energy scattering rate must also be different. Non-radial symmetrical shapes of the feed structure and other structures can meet these requirements.

In one embodiment, the distinct dielectrics are stacked in a given feed structure to control power dissipation from the feed to the aperture as the waves exit outward. For example, when more than one distinct dielectric is stacked up, the electrical energy or magnetic energy intensity can be concentrated in a particular dielectric. In a particular embodiment, a plastic layer and an air-like foam layer are used, the total thickness of which is less than λ _eff /2 at the operating frequency, resulting in a higher magnetic field energy concentration of the plastic than the air foam.

In one embodiment, for patch/iris demodulation, the control pattern is spatially controlled (eg, fewer components are activated at the beginning) to control the coupling above the aperture, depending on the feed direction and the desired aperture excitation weight, scattering More or less energy. For example, in one embodiment, the control style used at the beginning is less than the number of components that are activated at the other time. For example, at the beginning, there is only a certain percentage (eg 40%, 50%) of the elements that are to be activated during the first phase to form a beam close to the center of the cylindrical feed (patch) / Iris slotted pair) is activated and then activated from the remaining components farther away from the cylindrical feed. In an alternate embodiment, when the wave propagates away from the feed, the component must be continuously activated from the cylindrical feed. In another embodiment, a ridge feed network replaces the dielectric spacer (e.g., the plastic of spacer 205) and further controls that allow for the propagation of the feed wave alignment. The ridges can be used to produce asymmetric propagation (i.e., Poynting vector non-parallel wave vectors) at the feed to counter the l/r attenuation. In this way, the use of the ridges inside the feed assists in guiding energy to where it is needed. By directing more ridges and/or variable height ridges to the low energy zone, a more consistent illumination is produced at the aperture. Such a deviation from the purely radial feed configuration is that the direction of propagation of the feed wave may no longer be in a radial orientation. The slots above a ridge are strongly coupled, and the coupling forces between the ridges are weak. As such, depending on the desired coupling (to achieve the desired beam), the use of the ridges and the setting of the slots allow control coupling.

In yet another embodiment, a complex feed structure that provides one aperture illumination that is not circularly symmetric is used. Such an application may be a square aperture or a substantially non-circular aperture that is non-uniformly illuminated. In one embodiment, a non-radially symmetric dielectric is used which delivers more energy to certain regions than to other regions. In other words, the dielectric can have regions of different dielectric control. One such embodiment is a dielectric distribution that looks like a Maxwell fisheye lens. Such lenses can deliver unequal amounts of power to different parts of the array. In another embodiment, a ridge feed structure is used to deliver more energy to certain areas than to other areas.

In one embodiment, a plurality of the cylindrical feed sub-aperture antennas described herein are arranged in an array. In one embodiment, one or more additional feed structures are used. Also in one embodiment, a discrete amplification point is included. For example, an antenna system can include multiple antennas in an array, such as shown in Figures 2A or 2B. The array small system can be 3x3 (9 antennas total), 4x4, 5x5, etc., but other configurations are also possible. In such configurations, each antenna can have a separate feed. In an alternate embodiment, the number of boost points may be less than the number of feeds.

Advantages and benefits Improved beam performance

An advantage of embodiments of the inventive architecture is that it is superior to linearly fed beam performance. The natural built-in decrement at the edges helps achieve good beam performance.

In the array factor calculation, only the opening and closing elements from the 40 cm aperture can conform to the Federal Communications Commission (FCC) mask.

With this cylindrical feed, embodiments of the present invention do not have near-side impedance swings, and no band gap is created by the 1-wavelength periodic structure.

Embodiments of the present invention have no diffraction mode problems when scanning off-side.

Dynamic polarization

There are (at least) two component designs that can be used for the architecture described herein: circularly polarized components and paired linearly polarized components. The use of paired linearly polarized elements can dynamically change the sense of circular polarization by applying a phase delay or pre-adjusting to a set of elements rather than a second set. To achieve linear polarization, the phase advance of a set relative to the second set (solid set of entities) will be 180 degrees. Linear polarization can also be synthesized using only component pattern changes, providing a mechanism to track line polarization.

Operating bandwidth

The switch mode of operation has the opportunity to extend the dynamic and instantaneous bandwidth because the switch mode of operation does not require individual components to be tuned to a particular portion of their resonant curve. The antenna can be continuously operated through the amplitude and phase hologram portions of its operating range without significantly affecting performance. This makes the operating range much closer to the total tunable range.

The gap with the quartz/glass substrate may be small

The cylindrical feed structure can utilize a thin film transistor (TFT) architecture, meaning that it can function on quartz or glass. These substrates are much harder than the board and there are better known techniques for achieving a gap size of about 3 microns. A gap size of 3 microns will result in a switching speed of 14 milliseconds (ms).

Reduced complexity

The disclosed architecture described herein does not require any cutting work and requires only a single joining phase in manufacturing. This combination of architectures switches to TFT drive electronics, eliminating expensive materials and some tough requirements.

Although many variations and modifications of the present invention are apparent to those skilled in the art in the <RTIgt; Therefore, the details of the various embodiments are not intended to limit the scope of the scope of the invention, and the scope of the patent application itself recites only those features that are deemed necessary for the present invention.

Claims (24)

An antenna includes: an antenna feeding portion for inputting a cylindrical feed wave, the cylindrical feed wave system is concentrically propagated outward from the feed portion; and coupled to the plurality of surfaces of the antenna feed portion a radio frequency (RF) tunable slot array of the scatter antenna element, wherein the cylindrical feed wave interacts with the slot array to generate a beam, wherein the slot array includes a plurality of slots, the plurality The slotting is oriented at an angle relative to a direction of propagation of the cylindrical feed wave impinging on a central location of the respective slot. The antenna of claim 1, wherein the slotted array is dielectrically loaded. The antenna of claim 1, further wherein each slot is tuned to provide a desired scatter at a given frequency. The antenna of claim 3, wherein each of the plurality of slots is oriented at +45 degrees or -45 degrees with respect to the cylindrical feed wave impinging at the center of the respective slots. Having the slotted array include a first set of slots rotated +45 degrees with respect to the direction of propagation of the cylindrical feed wave and a second of -45 degrees relative to the direction of propagation of the cylindrical feed wave The group is slotted. The antenna of claim 1, wherein the slotted array further comprises: a plurality of patches, wherein each of the patches is co-located above one of the plurality of slots and is open The slots are spaced apart to form a patch/groove pair, each patch/groove pair being based on applying a voltage to The patch in the patch/slot pair is turned off or activated. The antenna of claim 5, wherein a dielectric is present between each of the plurality of slots and a patch associated therewith of the plurality of patches. The antenna of claim 6, wherein the dielectric comprises a liquid crystal. The antenna of claim 6 further comprising a controller that applies a control pattern that controls which of the patch/groove pairs are activated and deactivated thereby causing a beam to be generated. The antenna of claim 8, wherein the control pattern activates only a subset of the patches/groove pairs used to generate the beam during a first phase, and then initiates to generate the second phase The remaining patch/grooved pairs of the beam. The antenna of claim 5, wherein the plurality of patches are placed in a plurality of loops that are concentrically positioned relative to the antenna feed of the slot array. The antenna of claim 5, wherein the plurality of patches are included in a patch panel. The antenna of claim 5, wherein the plurality of patches are included in a glass layer. The antenna of claim 1, further comprising the cylindrical feed wave traveling into one of the dielectric layers. The antenna of claim 13, further comprising: a ground plane; a coaxial pin coupled to the ground plane for inputting the feed wave to the antenna, wherein the dielectric layer is coupled to the ground plane Slot array Between the columns. The antenna of claim 14 further comprising at least one RF absorber coupled to the ground plane and the array of slots for terminating unused energy to prevent unused energy from being reflected back through the antenna. The antenna of claim 14, further comprising: a gap conductor, wherein the dielectric layer is between the gap conductor and the slot array; a spacer between the gap conductor and the ground plane; and coupling The ground plane is to a side area of one of the slot arrays. The antenna of claim 16, wherein the side region includes two sides, each of the two side regions forming an angle such that the feed wave propagates from the spacer layer of the feed portion to the feed portion The dielectric layer. The antenna of claim 16, wherein the spacer comprises a foam. The antenna of claim 13, wherein the dielectric layer comprises plastic. The antenna of claim 13, wherein the dielectric layer is tapered. The antenna of claim 13, wherein the dielectric layer comprises a plurality of regions having different dielectric constants. The antenna of claim 13, wherein the dielectric layer comprises a plurality of discrete structures that affect propagation of the feed wave. The antenna of claim 1, further comprising the cylindrical feed wave traveling into one of the ridge feed networks. An antenna comprising: an antenna feeding portion for inputting a cylindrical feeding wave concentrically from the feeding portion; The feed wave travels through a dielectric layer; a plurality of slots that are oriented at an angle relative to a direction of propagation of the cylindrical feed wave; a plurality of patches, wherein each of the patches Co-locating over one of the plurality of slots and using a liquid crystal layer spaced apart from the slot to form a patch/groove pair, each patch/groove pair being based on applying a voltage to The patch is turned off or activated by a patch/slot pair designated by a control pattern, wherein the cylindrical feed wave impinges upon a center position of each of the slots The incoming wave interacts with the patch/grooving pair to produce a beam.