KR102652402B1 - An antenna having radio frequency liquid crystal (rflc) mixtures with high rf tuning, broad thermal operating ranges, and low viscosity - Google Patents

Abstract

A device comprising a radio frequency (RF) liquid crystal (RFLC) mixture with improved performance is disclosed. In one embodiment, improved performance includes high RF tuning, wide thermal operating range, and low viscosity. In one embodiment, the device has an antenna comprising an array of antenna elements having a plurality of antenna elements where each antenna element has a liquid crystal (LC) structure, wherein the LC structure has at least one of the following: and one or more mixtures thereof adapted to function laterally with one or more of hydrogen (H) or heteroatoms.

Description

AN ANTENNA HAVING RADIO FREQUENCY LIQUID CRYSTAL (RFLC) MIXTURES WITH HIGH RF TUNING, BROAD THERMAL OPERATING RANGES, AND LOW VISCOSITY}

preference

This patent application is in response to corresponding U.S. Provisional Patent Application No. 62/339,550, filed May 20, 2016, entitled “Radio Frequency Liquid Crystal (RFLC) Blends with High RF Tuning, Wide Thermal Operating Range, and Low Viscosity.” Priority is claimed and is incorporated herein by reference.

field of invention

Embodiments of the present invention relate to the field of radio frequency (RF) devices with liquid crystals (LC); More specifically, embodiments of the present invention relate to radio frequency (RF) devices with high RF tunability and low viscosity suitable for use in metamaterial-tuned antennas.

Recently, surface scattering antennas and other high-frequency devices have been disclosed that use liquid crystal (LC)-based metamaterial devices as part of the device. In the case of antennas, the LC has been used as part of the antenna element to tune the antenna element. The performance of these devices depends at least in part on the LC used. Therefore, it is desirable to develop LCs with properties that improve the performance of devices using them.

A device comprising a radio frequency (RF) liquid crystal (RFLC) mixture with improved performance is disclosed. In one embodiment, improved performance includes high RF tuning, wide thermal operating range, and low viscosity. In one embodiment, the device has an antenna comprising an array of antenna elements having a plurality of antenna elements where each antenna element has a liquid crystal (LC) structure, the LC structure having one of the following:

It comprises one or more mixtures adapted to function laterally with at least one or more of protons, hydrogen (H) or heteroatoms.

The invention will be more fully understood from the detailed description provided below and the accompanying drawings of various embodiments of the invention, but they should not be taken as limiting the invention to the specific embodiments, but are merely illustrative and It's for understanding.
Figure 1 shows a representation of the relative orientation of a liquid crystal (LC) nematic phase with respect to incident microwave radiation.
Figure 2(a) shows a computer modeling-based representation of field orientation and concentration inside a single element in meta-network antenna technology.
Figure 2(b) is a photograph of a representative meta-network antenna technology single element.
Figure 2(c) shows a representation of resonant frequency tuning.
Figure 3 shows approximate results from a radio frequency (RF) tuning study combined with Δn estimates made using a simple linear combination model.
Figures 4-8 show heat traces (differential scanning calorimetry) for selected LC mixtures.
Figure 9 shows a top view of one embodiment of a coaxial feed used to provide a cylindrical wave feed.
Figure 10 shows an aperture with one or more arrays of antenna elements arranged in concentric rings around the input feed of a cylindrically fed antenna.
Figure 11 shows a perspective view of one row of antenna elements including a ground plane and a reconfigurable resonator layer.
Figure 12 shows one embodiment of a tunable resonator/slot.
Figure 13 shows a cross-sectional view of one embodiment of a physical antenna aperture.
Figures 14A-14D show one embodiment of different layers for creating a slotted array.
Figure 15 shows a side view of one embodiment of a cylindrically fed antenna structure.
Figure 16 shows another embodiment of an antenna system with an outgoing wave.
Figure 17 shows one embodiment of the arrangement of matrix drive circuitry for antenna elements.
Figure 18 shows one embodiment of a TFT package.
Figure 19 is a block diagram of one embodiment of a communication system that performs dual reception simultaneously in a television system.
Figure 20 is a block diagram of another embodiment of a communication system with simultaneous transmit and receive paths.

A radio frequency (RF) device comprising a liquid crystal (LC) mixture and a method of using the same are disclosed. In one embodiment, the RF device may include an antenna, phased array, or optical modulator. In one embodiment, the LC mixture is a Radio Frequency Liquid Crystal (RFLC) mixture comprising a pi-conjugated mesogenic (liquid crystal) compound. In one embodiment, RFLC is a mixture suitable for use as an active element in meta-network antenna technology. To be useful in metanetworks antenna technology, RFLC mixtures must exhibit large voltage tunable RF dielectric anisotropy (optical Δη ≥ 0.3, RF Δε ≥ 1.33), acceptable temperature stability properties (long term at -40°C or below) It exhibits storage stability, clearing point ≥ 125°C), low RF loss (Δε/Tanδ ≥ 75), and acceptable viscoelastic properties (γi/K3 ≤ 15).

For purposes herein, “tuning range” is defined as the change in the RF dielectric constant, Δε(RF), and for optical applications it is defined as Δn.

In one embodiment, the liquid crystal mixture disclosed herein is a highly birefringent liquid crystal. High birefringence is typically recognized in the field as Δn > 0.3. These are: 1) Antenna applications such as holographic antennas, reflection-arrays and phased arrays based on resonant elements; and 2) spatial light modulators, such as those used in, for example, light imaging detection and ranging (LIDAR). In order for birefringent liquid crystals to be useful in the above applications, they must exhibit fast switching times and high tuning ranges.

Embodiments of the present invention include a series of liquid crystal mixtures in which large radio frequency (RF) dielectric tuning (high birefringence) is combined with low melting point and low rotational viscosity. In one example, the LC mixture has a high clearing point of 135°C combined with a low melting point of -63°C and a rotational viscosity of ~13. These key innovations enable these materials to offer fast switching speeds and operate at low temperatures. Increased birefringence is generally difficult to achieve because it is typically accompanied by increased viscosity and higher melting points. These materials enable the operation of the antenna active elements and thus the construction of antenna arrays.

In one embodiment, the liquid crystal used has 1) sufficient dielectric tuning (optical Δη ≥ 0.3, RF Δε ≥ 1.33); 2) acceptable relaxation time (~ 20 ms, γ1/K3 ≤ 15); 3) adequate thermal properties (long-term storage stability at -40°C or lower, clearing point ≥ 125°C); 4) Provides reasonable RF loss (Δε/Tanδ ≥ 75). This combination of characteristics is relatively unique. Any of these properties can be specifically optimized. However, implementing a material that meets all requirements simultaneously is much more difficult. Therefore, these materials (mixtures) and design strategies are inherently unique and valuable.

Most liquid crystals used commercially do not have a single molecule structure. They consist of mixtures of several compounds, each exhibiting unique physical and chemical properties. Therefore, molecular-level structure/property relationships are used to design single molecule structures with appropriate polarity and polarizability anisotropy. These same structure/property relationships are used simultaneously to create a condensed phase (liquid crystal mesophase) that satisfies all operational requirements.

Embodiments of the present invention not only provide specific chemical "recipes" for usable LC mixtures, but also provide a set of general concepts that can be further used to create new mixtures with rationally designed properties. .

A given specific chemical structure can be used as a multiple mixture “recipe” to tailor specific chemical and physical properties. The general structure/property relationships demonstrated can be used to design new materials with significantly improved performance properties.

In one embodiment, the highly birefringent liquid crystals disclosed herein produce large length/width polarization anisotropy at the molecular level. In one embodiment, this is achieved by creating a long, rigid π-electron conjugated core (e.g., tolane). As is (unfunctionalized), such molecules have very high melting points due to strong intermolecular interactions. In one embodiment, a long carbon tail is attached to one end to lower the melting point and form a nematic (liquid crystal) phase. At the opposite end, for example, isothiocyanate (NCS), trifluoromethoxy (OCF ₃ ), cyano (CN), bromide (Br) or tifluorophenyl. , C ₆ H ₂ F ₃ ), a polar group is used to further increase birefringence and introduce a permanent dipole.

This idea can be expressed through the general structures above (GS 1, GS 2, GS 3 and GS 4). For GS 1, GS 2 and GS 4, the core is expressed in units of the number m. This core can be laterally functional with protons, H, and/or heteroatoms, for example fluorine (F), bromide (Br) or chlorine (Cl). For example methyl (CH ₃ ), ethyl (CH ₂ CH ₃ ), propyl (CH ₂ CH ₂ CH ₃ ) or methoxy (OCH ₃ ), ethoxy (OCH ₂ CH ₃ ), propoxy (OCH ₂ CH ₃ ) or an alkyl group such as trifluoromethoxy (OCF ₃ ) can also be introduced at various R positions. This lateral functionalization modifies intermolecular interactions to disfavor the formation of a smectic phase and/or modify the rotational viscosity γ, elastic constant κ and melting point T _m . Lengthening the core (increasing m) generally increases birefringence. In this case, A is a saturated carbon chain as seen in structures 1 to 6 below, or an alkoxy (OCnH(2n+1)), or a similarly functionalized cyclohexyl and/or phenyl moiety. am. The longer the carbon chain, the lower the melting point generally. In this case, B is a second group such as isothiocyanate (NCS), trifluoromethoxy (OCF ₃ ), cyano (CN), bromide (Br) or thifluorophenyl (C ₆ H ₂ F ₃ ). It is an alkyl or alkoxy chain or polar group. Structure GS 3 illustrates a complementary structural motif where Z and Y independently represent a single or triple bond.

Create a liquid crystal mixture

The following are exemplary embodiments of six LC chemical structures that can be used as metamaterial elements in antenna elements.

For the six structures of Scheme 1 shown above, the liquid crystal mixture contains any or all of the above structures, where D = CH ₂ , O, S, Se; R1-R12 = C _n H _(2n+1) , H, F, Cl, SC _n H _(2n+1) , SeC _n H _(2n+1) , Br; and X = NCS, F, Br, Cl, H.

None of the compounds shown in Scheme 1 as Structures 1 to 6 are liquids at room temperature. To become a liquid crystal, the mixture must be a liquid within a useful operating temperature range. To form a liquid at room temperature, by weighing out specific amounts of each compound, mixing them together, and then heating until the compounds melt and mix together, the liquids shown in the general structures GS 1, GS 2, GS 3 and specific structures 1 to 6 are formed. Mixtures of similar compounds such as those are prepared. Suitable mixtures do not re-solidify (freeze) at room temperature. Mixtures can be as simple as mixing one particular basic structure with different length carbon chains (n = 1-7), or as complex as adding many different structures at varying weight percentages.

Basic structures such as those exemplified by 1-6 and/or GS 1 / GS 2 may not only differ in terms of physical properties, but also in terms of birefringence Δn. Therefore, mixtures containing different weight percentages will also have different optical properties. For the purposes herein, the base mixture may be tailored to have specific physical and optical properties as described above.

Naming of structures and common units (naming)

Structures 1 to 6 all share subunits.

Structure 1 is known as cyclohexyl-phenyl. It consists of a cyclohexyl ring and a phenyl ring attached together. On the left, n refers to the number of carbons in the saturated hydrocarbon tail. The number of carbons generally varies between n = 1 and n = 7, where n = 1 methyl; n = 2 ethyl; n = 3 profiles; n = 4 butyl; n = 5 pentyl; n = 6 hexyl; n = 7 heptyl. In one embodiment, D is a carbon and two hydrogens (extra carbon is added), X = NCS and n = 4. In this case, structure number 1 is designated pentyl-cyclohexylphenyl isocyanate. If the same basic structure is maintained and D is changed to oxygen, the structure is named butoxycyclohexylphenyl isocyanate.

Structure 2 is referred to herein as tolane. Tolein is basically two phenyl rings at either end of a triple bond. Using the same naming convention, in one example, when D = CH2 and X = NCS, structure number 2 is named pentyl-isothiocyanato tolane.

Structure 3 is a combination of Structures 1 and 2. This is referred to herein as cyclohexyl-tolane. In one embodiment, D = CH2 and X = NCS. In this case, structure 3 is named pentyl-isothiocyantho cyclohexyl-tolane.

Structure 4 is referred to herein as phenyl-tolane. A phenyl ring is added to the basic tolane structure. In one embodiment, D = CH2 and X = NCS. In this case, structure 4 is named pentyl-isothiocyantho phenyl-tolane.

Structure 5 is referred to herein as phenyl-bis-tolane. It has two triple bonds between a phenyl group and another phenyl ring. In one embodiment, D = CH2 and X = NCS. In this case, structure 5 is named pentyl-isothiocyantho phenyl-bistolane.

Structure 6 is referred to herein as a terphenyl having three phenyl rings attached together. In one embodiment, D = CH2 and X = NCS. In this case, structure 6 is named pentyl-isothiocyantho terphenyl.

Scheme 2 below illustrates another set of mixtures for use in the antennas disclosed herein. Each mixture includes the use of NCS terminal groups.

LC single molecule and mixture test results

Table 1: Thermal data collected corresponding to selected LC monoliths in Scheme 2.

compound melting
(Tm) clearing
(Tc) frieze
(Tcr) △n 11.7h

11.7i

111.7f

111.7h

4TOLCl

4OTOLCl

FNCST1

TFNCST1

111.7n

111.7o 64.2

53.5

103

96.9

44.4

81.9

49

68

77

63 71.6

64.5

--

--

--

--

--

218

239

243 --

34.2

--

51

--

61.7

--

--

--

-- 0.28

--

--

--

0.28

0.26

~0.29

0.50

~0.38

~0.38

Table 2: Mixing ratio and tuning results (tuning is given in GHz as △f)

As mentioned above, useful liquid crystal mixtures are prepared by combining multiple unique base structures (LC monoliths) in varying weight percentages. Scheme 2 shows the library of LC monoliths synthesized for this work. Table 1 shows the thermal properties of the LC monolith shown in Scheme 2. The term “melt” is used to refer to the melting point, i.e., the temperature at which a compound changes phase from a crystalline solid to a liquid. The term “freeze” refers to the freezing point, i.e. the temperature at which freezing reoccurs (recurs) upon cooling at a linear rate of 10° C./min. Birefringence Δn is indicated where available. The clearing point represents the temperature at which the nematic phase becomes isotropic (and visually changes from milky white in appearance to clear). From inspection of Table 1, the lowest melting LC monomer, 4TOLCl, melts at 44.4°C. This is significantly higher than room temperature (~19°C). Likewise, the highest clearing point is indicated by 111.7o.

Table 2 shows various mixtures prepared using the library of compounds. The weight percent of each compound used is given, and the resulting thermal and tuning properties are given.

It can be further illustrated by inspection of Table 2 that mixtures can be prepared using the LC monolith shown in Scheme 2, freezing as low as -64°C and clearing as high as 153°C. These values are comparable to the widest nematic temperature range reported to date.

Figures 1 and 2 (a) to (c) illustrate the concept of tuning regarding meta-network antenna technology. This concept is best described in terms of a single element among many that make up a meta-network element array based antenna according to one embodiment. Nematic phase liquid crystal mixtures, such as those discussed herein, are embedded within a single device in meta-network antenna technology. Figure 1 shows a representation of the relative orientation of the LC nematic phase with respect to incident microwave radiation. When an electric field is applied, the LC changes its direction and thus generates Δf, which corresponds to the equation given in Figure 1 through its Δn. This Δf determines the behavior of the antenna technology.

Figure 2(a) shows a computer modeling-based representation of field orientation and concentration inside a single element in meta-network antenna technology. Figure 2(b) is a photograph of a representative meta-network antenna technology single element. Figure 2(c) shows an expression of resonance frequency tuning, referred to as Δf in Tables 2 and 3.

Figure 3 shows approximate results from a RF tuning study combined with Δn estimates made using a simple linear combination model. Using linear combination analysis for plots 13.1 and 13.2, Δn for 13.1 and 13.2 can be estimated to be 0.37 and 0.34, respectively. Plotting this against their average tuning results, we need to reach a Δn of ~0.4 to achieve tuning at ~1.85 GHz.

As mentioned above, the simplest way to increase Δn is to increase the amount of the highest Δn mixture component (in this case, TFNCST1). However, this solution does not maintain good thermal performance unless the entire mixture is reformed. For example, 13.1 indicates the largest Δn for the mixture given in Table 2, but it also indicates the narrowest nematic temperature range. To solve this, several new mixtures were investigated. The most successful mixture to date was 13.8. This mixture has an estimated Δn of ~0.39 - ~0.4. 13.8 indicates a very wide nematic temperature range with a particularly high clearing point. This is accompanied by a somewhat increased viscosity, but the increase is not dramatic. To solve this, the amount of 5CHBT can be increased without any significant decrease in Δn. Bulk testing at -20°C indicates that 13.8 appears to remain fairly stable at this temperature.

Microwave loss and tuning measurements

Table 3: Perpendicular dielectric constant ε'perp and parallel dielectric constant ε'para, Δε (13 GHz) and loss tangent for selected LC mixtures measured at 13.17 GHz.

It should be noted that as Δε(Δn) increases, the RF loss also increases for the mixture shown here. However, in the case of 13.8, this loss is acceptable for meta-network antenna technology.

Figures 4-8 show heat traces (differential scanning calorimetry) for selected LC mixtures. These values correspond to those given in Table 2.

The above-described LC may be included in antenna embodiments having the following features.

Examples of Antenna Embodiments

The techniques described above can be used with flat panel antennas. Embodiments of such flat panel antennas are disclosed. Flat panel antennas include one or more arrays of antenna elements on the antenna aperture. In one embodiment, the antenna elements include liquid crystal cells. In one embodiment, the flat panel antenna is a cylindrically fed antenna that includes matrix drive circuitry to uniquely address and drive each of the antenna elements that are not placed in rows and columns. In one embodiment, the elements are placed in rings.

In one embodiment, the antenna aperture with one or more arrays of antenna elements consists of a plurality of segments connected to one another. When connected to each other, the combination of segments forms closed concentric rings of antenna elements. In one embodiment, the concentric rings are concentric with respect to the antenna feed.

Overview of Examples of Antenna Systems

In one embodiment, the flat panel antenna is part of a metamaterial antenna system. Embodiments of a metamaterial antenna system for communications satellite earth stations are described. In one embodiment, the antenna system operates on a mobile platform (e.g., air, maritime, land, etc.) operating using Ka-band frequencies or Ku-band frequencies for civil commercial satellite communications. It is a component or subsystem of a satellite earth station (ES). Note that embodiments of the antenna system may also be used in earth stations that are not on mobile platforms (eg, fixed or transportable earth stations).

In one embodiment, the antenna system uses surface scattering metamaterial technology to form and steer transmit and receive beams through separate antennas. In one embodiment, the antenna systems are analog systems, as opposed to antenna systems that employ digital signal processing to electrically form and steer beams (such as phased array antennas).

In one embodiment, the antenna system consists of three functional subsystems: (1) a wave guiding structure with a cylindrical wave feed architecture; (2) an array of wave scattering metamaterial unit cells that are part of the antenna elements; and (3) a control structure for commanding the formation of a tunable radiation field (beam) from metamaterial scattering elements using holographic principles.

Examples of waveguide structures

Figure 9 shows a top view of one embodiment of a coaxial feed used to provide a cylindrical wave feed. Referring to FIG. 9, the coaxial feed includes a center conductor and an outer conductor. In one embodiment, a cylindrical wave feed architecture feeds the antenna from a central point with the excitation spreading outward in a cylindrical manner from the feed point. In other words, an antenna fed in a cylindrical shape generates an outward traveling concentric feed wave. However, the shape of the cylindrical feed antenna around the cylindrical feed may be circular, square, or any shape. In another embodiment, a cylindrically fed antenna generates an inward traveling feed wave. In this case, the feed wave most naturally emerges from a circular structure.

Figure 10 shows an aperture with one or more arrays of antenna elements arranged in concentric rings around the input feed of a cylindrically fed antenna.

antenna elements

In one embodiment, the antenna elements include a group of patch antennas. This group of patch antennas includes an array of scattering metamaterial elements. In one embodiment, each scattering element within the antenna system is part of a unit cell consisting of a lower conductor, a dielectric substrate, and an upper conductor, with the upper conductor It contains a complementary electric inductive-capacitive resonator (“complementary electric LC” or “CELC”) that is etched or deposited on the top conductor. As those skilled in the art will understand, LC in the context of CELC refers to inductance-capacitance as opposed to liquid crystal.

In one embodiment, the liquid crystal (LC) is disposed in a gap around the scattering element. This LC is driven by the direct drive embodiments described above. In one embodiment, the liquid crystal is encapsulated within each unit cell, separating the lower conductor associated with the slot from the upper conductor associated with the patch. Liquid crystals have a permittivity that is a function of the orientation of the molecules comprising the liquid crystal, and the orientation of the molecules (and thus the permittivity) can be controlled by adjusting the bias voltage applied to the liquid crystal. Taking advantage of these properties, in one embodiment, the liquid crystal integrates an on/off switch for the transfer of energy from a guided wave to the CELC. When switched on, the CELC emits electromagnetic waves equivalent to an electrically small dipole antenna. Note that the teachings herein are not limited to having liquid crystals operating in a binary fashion with respect to energy transfer.

In one embodiment, the feed geometry of this antenna system allows the antenna elements to be placed at a forty-five degree (45°) angle with respect to the vector of the wave in the wave feed. Note that other positions may be used (eg, at a 40° angle). This position of the elements allows control of the free space wave received by or transmitted/radiated from the elements. In one embodiment, the antenna elements are arranged with inter-element spacing less than the free space wavelength of the antenna's operating frequency. For example, if there are four scattering elements per wavelength, the elements in a 30 GHz transmit antenna would be approximately 2.5 mm (i.e., one quarter of the 10 mm free space wavelength at 30 GHz).

In one embodiment, the two sets of elements are perpendicular to each other and, if controlled to the same tuning state, have the same amplitude excitation at the same time. Rotating them +/-45 degrees relative to the feed wave excitation achieves both desired properties at once. Rotating one set to 0 degrees and the other set to 90 degrees will achieve the perpendicular goal, but will not achieve the same amplitude excitation goal. Note that 0 degrees and 90 degrees can be used to achieve isolation when feeding an array of antenna elements in a single structure from two sides.

The amount of radiated power from each unit cell is controlled by applying a voltage to the patch (potential across the LC channel) using a controller. The traces for each patch are used to provide voltage to the patch antenna. The voltage is used to tune or detune the resonant frequencies of the individual elements to achieve capacitance and thus beam forming. The voltage required depends on the liquid crystal mixture being used. The voltage tuning characteristics of liquid crystal mixtures are mainly described by the threshold voltage and saturation voltage. At the threshold voltage, the liquid crystal begins to be affected by the voltage, and above the saturation voltage, the increase in voltage causes the liquid crystal to Does not result in major conformity. These two characteristic parameters may vary for different liquid crystal mixtures.

In one embodiment, as described above, a matrix drive patches voltages to drive each cell separately from all other cells without having to have a separate connection for each cell (direct drive). It is used to authorize. Due to the high density of devices, matrix driving is an efficient way to handle each cell individually.

In one embodiment, the control structure for the antenna system has two main components: the antenna array controller, including the drive electronics for the antenna system, resides below the wave scattering structure, while the matrix driven switching array are interspersed throughout the radiating RF array in a manner that does not interfere with the radiation. In one embodiment, the drive electronics for the antenna system are those used in commercial television devices to adjust the bias voltage for each scattering element by adjusting the amplitude or duty cycle of the AC bias signal for the element. Includes commercial off-the-shelf LCD controls.

In one embodiment, the antenna array controller also includes a microprocessor executing software. The control structure also uses sensors (e.g., GPS receiver, 3-axis compass, 3-axis accelerometer, 3-axis gyro, 3-axis magnetometer, etc.) to provide position and orientation information to the processor. It may contain Position and orientation information may be provided to the processor by other systems within the earth station and/or may not be part of the antenna system.

More specifically, the antenna array controller controls which elements are turned off and at what phase and amplitude level at the frequency of operation. The devices are selectively detuned to frequency operation by applying a voltage.

For transmission, a controller supplies an array of voltage signals to RF patches to create a modulation or control pattern. Control patterns cause the elements to enter different states. In one embodiment, multistate control is used, wherein various elements are turned on and off at various levels and modulated by a square wave (i.e., sinusoidal gray shaded modulation pattern). In contrast to the gray shade modulation pattern), it is closer to the sine control pattern. In one embodiment, rather than some elements radiating and some not radiating, some elements radiate more strongly than others. Variable radiation is achieved by applying specific voltage levels that adjust the liquid crystal dielectric constant by various amounts, thereby variably detuning the devices and causing some devices to radiate more than others.

The generation of a focused beam by a metamaterial array of devices can be explained by the phenomena of constructive and destructive interference. Individual electromagnetic waves combine if they have the same phase when they meet in free space (constructive interference), and waves cancel each other out if they have opposite phases when they meet in free space (destructive interference). If the slots of a slotted antenna are arranged so that each successive slot is located at a different distance from the excitation point of the guided wave, the scattered wave from that element will It will have a different phase from the scattered wave. If the slots are spaced by a quarter of the guided wavelength, each slot will scatter waves with a quarter phase lag from the previous slot.

By using an array, the number of patterns of constructive and destructive interference that can be created uses the principles of holography to direct the beams in theoretically arbitrary directions plus or minus 90 degrees from the bore sight of the antenna array. It can be increased so that it can be directed to . So, by controlling which metamaterial unit cells are turned on or off (i.e., by changing the pattern of which cells are turned on and which cells are turned off), different patterns of constructive and destructive interference can be created. , the antenna can change the direction of the main beam. The time required to turn the unit cells on and off dictates the speed at which the beam can be switched from one position to another.

In one embodiment, the antenna system produces one steerable beam for the uplink antenna and one steerable beam for the downlink antenna. In one embodiment, the antenna system uses metamaterial technology to receive beams from the satellite and decode the signals and form transmit beams aimed toward the satellite. In one embodiment, the antenna systems are analog systems, as opposed to antenna systems that employ digital signal processing to electrically form and steer beams (such as phased array antennas). In one embodiment, the antenna system is considered to be a "surface" antenna, which is planar and relatively low profile, especially when compared to a conventional satellite dish receiver.

Figure 11 shows a perspective view of one row of antenna elements including a ground plane and a reconfigurable resonator layer. Reconfigurable resonator layer 1230 includes an array of tunable slots 1210. The array of tunable slots 1210 can be configured to point the antenna in a desired direction. Each of the tunable slots can be tuned/adjusted by changing the voltage applied to the liquid crystal.

Control module 1280 is coupled to reconfigurable resonator layer 1230 for modulating the array of tunable slots 1210 by varying the voltage across the liquid crystal of FIG. 11 . Control module 1280 may include a Field Programmable Gate Array (FPGA), microprocessor, controller, System-on-a-Chip (SoC), or other processing logic. In one embodiment, control module 1280 includes logic circuitry (e.g., a multiplexer) to drive an array of tunable slots 1210. In one embodiment, control module 1280 receives data containing specifications for a holographic diffraction pattern to be driven onto an array of tunable slots 1210. Holographic diffraction patterns may be generated in response to the spatial relationship between the antenna and the satellite such that the holographic diffraction pattern steers the downlink beams (and uplink beams if the antenna system is performing transmission) in an appropriate direction for communication. Although not shown in each figure, a control module similar to control module 1280 may drive each array of tunable slots described in the figures of this disclosure.

Radio frequency (RF) holography is also possible using similar techniques, where a desired RF beam can be generated when an RF reference beam encounters an RF holographic diffraction pattern. In the case of satellite communications, the reference beam is in the form of a feed wave, such as feed wave 1205 (approximately 20 GHz in some embodiments). Converting the feed wave (for transmission or reception purposes) into a radiated beam. To convert, an interference pattern is calculated between the desired RF beam (object beam) and the feed wave (reference beam). The interference pattern is driven as a diffraction pattern onto an array of tunable slots 1210 such that the feed wave is steered into the desired RF beam (with the desired shape and direction). In other words, the feed wave encountering the holographic diffraction pattern reconstructs the object beam that is formed according to the design requirements of the communication system. The holographic diffraction pattern includes the excitation of each element and is calculated by Whoiogram = win * wout, where win is the wave equation in the waveguide and wout is the wave equation for the outgoing wave.

12 shows one embodiment of a tunable resonator/slot 1210. The tunable slot 1210 includes an iris/slot 1212, a radiating patch 1211, and a liquid crystal 1213 disposed between the iris 1212 and the patch 1211. In one embodiment, copy patch 1211 is co-located with iris 1212.

Figure 13 shows a cross-sectional view of one embodiment of a physical antenna aperture. The antenna aperture surface includes a metal layer 1236 in an iris layer 1233 included in the reconfigurable resonator layer 1230, and a ground plane 1245. In one embodiment, the antenna aperture of Figure 13 includes a plurality of tunable resonators/slots 1210 of Figure 12. Iris/slot 1212 is defined by openings in metal layer 1236. A feed wave, such as feed wave 1205 of FIG. 11, may have a microwave frequency compatible with satellite communication channels. The feed wave propagates between the ground plane 1245 and the resonator layer 1230.

Reconfigurable resonator layer 1230 also includes a gasket layer 1232 and a patch layer 1231. The gasket layer 1232 is disposed below the patch layer 1231 and the iris layer 1233. Note that in one embodiment, a spacer may replace gasket layer 1232. In one embodiment, iris layer 1233 is a printed circuit board (PCB) that includes a copper layer, such as metal layer 1236. In one embodiment, iris layer 1233 is glass. Iris layer 1233 may be other types of substrates.

Openings may be etched into the copper layer to form slots 1212. In one embodiment, iris layer 1233 is conductively coupled to other structures (e.g., waveguides) of Figure 13 by a conductive bonding layer. Note that in the embodiment, the iris layer is not conductively bonded to a conductive bonding layer, but is instead interfaced with a non-conducting bonding layer.

Patch layer 1231 may also be a PCB containing the same metal as radiation patches 1211. In one embodiment, gasket layer 1232 includes spacers 1239 that provide mechanical standoff to define the dimension between metal layer 1236 and patch 1211. In one embodiment, the spacers are 75 microns, but other sizes may be used (eg, 3-200 mm). As described above, in one embodiment, the antenna aperture of FIG. 13 includes a plurality of tunable resonators/slots, with tunable resonators/slots 1210 being patch 1211 and liquid crystal 1213 of FIG. 12. , and Iris (1212). The chamber for liquid crystal 1213 is defined by spacers 1239, iris layer 1233, and metal layer 1236. When the chamber is filled with liquid crystal, patch layer 1231 may be laminated onto spacers 1239 to seal the liquid crystal within resonator layer 1230.

The voltage between patch layer 1231 and iris layer 1233 can be modulated to tune the liquid crystal within the gap between the patch and the slots (eg, tunable resonator/slot 1210). Adjusting the voltage across liquid crystal 1213 changes the capacitance of the slot (e.g., tunable resonator/slot 1210). Accordingly, the reactance of a slot (e.g., tunable resonator/slot 1210) can be varied by varying the capacitance. The resonant frequency of the slot 1210 is also determined by the equation It varies depending on , where f is the resonant frequency of the slot 1210, and L and C are the inductance and capacitance of the slot 1210, respectively. The resonant frequency of the slot 1210 affects the energy radiated from the feed wave 1205 propagating through the waveguide. As an example, if the feed wave 1205 is 20 GHz, the resonant frequency of the slot 1210 can be adjusted (by changing the capacitance) to 17 so that the slot 1210 does not couple substantially any energy from the feed wave 1205. Can be tuned to GHz. Alternatively, the resonant frequency of the slot 1210 may be adjusted to 20 GHz so that the slot 1210 combines energy from the feed wave 1205 and radiates the energy into free space. The examples given are in two parts (either fully copied or not copied at all), but full gray scale control of the reactance of the slot 1210 and thus the resonant frequency is provided in a multi-valued range. ) is possible with voltage variance. Thus, the energy radiated from each slot 1210 can be precisely controlled such that detailed holographic diffraction patterns can be formed by the array of tunable slots.

In one embodiment, the tunable slots within a row are spaced apart from each other by λ/5. Other intervals may be used. In one embodiment, each tunable slot in a row is spaced apart by λ/2 from the nearest tunable slot in an adjacent row, such that commonly oriented tunable slots in different rows are spaced by λ/4, Other intervals are possible (eg λ/5, λ/6.3). In another embodiment, each tunable slot in a row is spaced λ/3 from the nearest tunable slot in an adjacent row.

Examples include U.S. Patent Application No. 14/550,178, filed on November 21, 2014, entitled “Dynamic Polarization and Coupling Control from a Steerable Cylindrically Fed Holographic Antenna” and US Patent Application No. 14/550,178, entitled “Ridged Waveguide Feed Structures for It uses reconfigurable metamaterial technology as described in U.S. Patent Application No. 14/610,502, filed on January 30, 2015, entitled “Reconfigurable Antenna.”

Figures 14A-14D show one embodiment of different layers for creating a slotted array. The antenna array includes antenna elements arranged in rings, such as the example rings shown in FIG. 10. Note that in this example, the antenna array has two different types of antenna elements used for two different types of frequency bands.

Figure 14a shows part of the first iris board layer with positions corresponding to slots. Referring to Figure 14A, the circles are open areas/slots in the metallization on the bottom side of the iris substrate and are for controlling the coupling of the elements to the feed (feed wave). Note that this layer is an optional layer and is not used in all designs. Figure 14B shows a portion of the second iris board layer including slots. Figure 14C shows patches on a portion of the second iris board layer. Figure 14D shows a top view of a portion of the slotted array.

Figure 15 shows a side view of one embodiment of a cylindrically fed antenna structure. The antenna uses a double-layer feed structure (i.e., two layers of the feed structure) to generate an inwardly traveling wave. In one embodiment, the antenna includes a circular outer shape, but this is not required. In other words, non-circular inward traveling wave structures can be used. In one embodiment, the antenna structure of FIG. 15 includes the coaxial feed of FIG. 9.

Referring to FIG. 15, a coaxial pin 1601 is used to excite the field at the lower level of the antenna. In one embodiment, coaxial pin 1601 is a readily available 50Ω coaxial pin. Coaxial pin 1601 is connected (e.g., bolted) to the bottom of the antenna structure, which is a conducting ground plane 1602.

Apart from the conductive ground plane 1602, there is an interstitial conductor 1603, which is an internal conductor. In one embodiment, conductive ground plane 1602 and interstitial conductor 1603 are parallel to each other. In one embodiment, the distance between ground plane 1602 and interstitial conductor 1603 is 0.1-0.15". In another embodiment, this distance may be λ/2, where λ is the frequency of operation. It is the wavelength of the wave.

Ground plane 1602 is separated from interstitial conductor 1603 through spacer 1604. In one embodiment, spacer 1604 is a spacer such as foam or air. In one embodiment, spacer 1604 includes a plastic spacer.

A dielectric layer 1605 exists on the interstitial conductor 1603. In one embodiment, dielectric layer 1605 is plastic. The purpose of dielectric layer 1605 is to slow the traveling wave with respect to free space velocity. In one embodiment, dielectric layer 1605 slows the traveling wave relative to free space by as much as 30%. In one embodiment, a suitable range of refractive indices for beamforming is 1.2-1.8, where free space by definition has a refractive index equal to 1. To achieve this effect, other dielectric spacer materials may be used, for example plastic. Note that materials other than plastic may be used as long as the desired effect is achieved. In contrast, materials with distributed structures, for example periodic sub-wavelength metallic structures that can be machined or lithographically defined, are used as dielectrics. (1605).

An RF-array 1606 is on top of the dielectric 1605. In one embodiment, the distance between interstitial conductor 1603 and RF-array 606 is 0.1-0.15". In another embodiment, this distance may be Aeff/2, where Aeff is the amount of energy in the medium at the design frequency. It is the effective wavelength.

The antenna includes sides 1607 and 1608. Sides 1607 and 1608 allow the traveling wave feed from the coaxial pin 1601 to travel from the area below the interstitial conductor 1603 (spacer layer) to the interstitial conductor 1603 through reflection. (Dielectric layer) is angled to cause propagation to the area above. In one embodiment, the angle of sides 1607 and 1608 is a 45° angle. In an alternative embodiment, sides 1607 and 1608 may be replaced with continuous radii to achieve the reflection. Figure 15 shows angled sides with an angle of 45 degrees, but other angles can be used to achieve signal transmission from lower level feed to upper level feed. In other words, given that the effective wavelength in the lower feed will generally be different than in the upper feed, a slight deviation from the ideal 45° angle may be used to aid transmission from the lower to the upper feed level. For example, in another embodiment, 45° angles are replaced with a single step. These steps at one end of the antenna run through the dielectric layer, interstitial conductor, and spacer layer. Two identical steps exist at different ends of these layers.

In operation, when a feed wave is fed in from the coaxial pin 1601, the wave flows concentrically ( It is oriented concentrically and moves outward. Concentrically outgoing waves are reflected by sides 1607 and 1608 and travel inward within the area of interstitial conductor 1603 and RF array 1606. Reflection from the edges of the circular perimeter causes the waves to be in phase (i.e., this is in-phase reflection). The traveling wave is slowed down by the dielectric layer 1605. At this point, the traveling wave begins interacting and exciting elements in the RF array 1606 to obtain the desired scattering.

To terminate the traveling wave, a termination 1609 is included in the antenna at its geometric center. In one embodiment, termination 1609 includes a pin termination (e.g., a 50Ω pin). In another embodiment, termination 1609 includes an RF absorber that terminates unused energy to prevent it from reflecting back through the feed structure of the antenna. This may be used on top of the RF array 1606.

Figure 16 shows another embodiment of an antenna system with outgoing waves. Referring to Figure 16, two ground planes 1610 and 1611 are substantially parallel to each other with a dielectric layer 1612 (eg, a plastic layer, etc.) between the ground planes. RF absorbers 1619 (e.g., resistors) are coupled together to two ground planes 1610 and 1611. A coaxial pin 1615 (e.g., 50Ω) feeds the antenna. RF array 1616 is over dielectric layer 1612 and ground plane 1611.

In operation, the feed wave is fed through the coaxial pin 1615, moves concentrically outward, and interacts with elements of the RF array 1616.

The cylindrical feeds in both antennas of Figures 15 and 16 improve the service angle of the antennas. Instead of a service angle of plus or minus 45 degrees azimuth (±45° Az) and plus or minus 25 degrees elevation (±25° El), in one embodiment, the antenna system has a service angle of plus or minus 45 degrees angular (±45° Az) from the bore site in one embodiment. It has a service angle of 75°). As with any beamforming antenna consisting of multiple individual radiators, the overall antenna gain depends on the gains of the constituent elements, which are themselves angle-dependent. When using common radiating elements, overall antenna gain typically decreases as the beam is aimed further away from the bore sight. At 75 degrees off bore sight, a significant gain drop of approximately 6 dB is expected.

Embodiments of antennas with cylindrical feeds solve one or more problems. This dramatically simplifies the feed structure compared to antennas fed with a corporate divider network, thus reducing the overall required antenna and antenna feed volume; Reduces sensitivity to manufacturing and control errors by maintaining high beam performance with coarser controls (extending to simple binary control); Cylindrically oriented feed waves provide a more advantageous side lobe pattern than rectilinear feeds because they give rise to spatially variable side lobes in the far field; Allowing polarization to be dynamic, including allowing left-hand circular, right-hand circular, and linear polarization without requiring a polarizer. Includes ;

Array of wave scattering elements

RF array 1606 in FIG. 15 and RF array 1616 in FIG. 16 include a wave scattering subsystem that includes a group of patch antennas (i.e., scatterers) that operate as radiators. do. This group of patch antennas includes an array of scattering metamaterial elements.

In one embodiment, each scattering element within the antenna system is part of a unit cell consisting of a lower conductor, a dielectric substrate, and an upper conductor, the upper conductor comprising a complementary electrical inductive-capacitive resonator that is etched or deposited on the upper conductor. ("complementary electric LC" or "CELC") is built-in.

In one embodiment, liquid crystals (LC) are implanted into the gap around the scattering element. Liquid crystal is encapsulated within each unit cell, separating the lower conductor associated with the slot from the upper conductor associated with the patch. Liquid crystals have a dielectric constant that is a function of the orientation of the molecules comprising the liquid crystal, and the orientation of the molecules (and thus the dielectric constant) can be controlled by adjusting the bias voltage applied to the liquid crystal. Using these properties, the liquid crystal acts as an on/off switch for the transfer of energy from guided waves to the CELC. When switched on, the CELC emits electromagnetic waves like a small electrical dipole antenna.

Controlling the thickness of the LC increases the beam switching speed. A 50 percent (50%) reduction in the gap (thickness of the liquid crystal) between the lower and upper conductors results in a four-fold increase in speed. In another embodiment, the thickness of the liquid crystal results in a beam switching speed of approximately 14 milliseconds (14 ms). In one embodiment, the LC is doped by methods well known in the art to improve responsiveness such that the 7 millisecond (7 ms) requirement can be met.

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

The phase of the electromagnetic wave produced by a single CELC can be selected by the position of the CELC on the vector of the guided wave. Each cell generates a guided wave parallel to the CELC and a wave in phase. Because the CELC is smaller than the wavelength, the output wave has the same phase as the guided wave as it passes below the CELC.

In one embodiment, the feed geometry of this antenna system allows the CELC elements to be placed at a forty-five degree (45°) angle with respect to the vector of the wave in the wave feed. This position of the elements allows control of the polarization of the free space wave generated by or received by the elements. In one embodiment, the CELCs are arranged with an inter-element spacing that is less than the free space wavelength of the antenna's operating frequency. For example, if there are four scattering elements per wavelength, the elements in a 30 GHz transmit antenna would be approximately 2.5 mm (i.e., one quarter of the 10 mm free space wavelength at 30 GHz).

In one embodiment, the CELC is implemented with a patch antenna comprising patches co-located over a slot with a liquid crystal between the two. In this respect, the metamaterial antenna acts like a slotted (scattering) waveguide. For a slotted waveguide, the phase of the output wave depends on the position of the slot relative to the guided wave.

cell placement

In one embodiment, the antenna elements are arranged on the cylindrical feed antenna aperture in a way that allows for a systematic matrix drive circuit. The arrangement of cells includes arrangement of transistors for driving the matrix. Figure 17 shows one embodiment of the arrangement of matrix drive circuitry with respect to antenna elements. Referring to FIG. 17, the row controller 1701 is connected to the transistors 1711 and 1712 through row selection signals (Row1 and Row2), respectively, and the column controller 1702 is connected to the transistors through the column selection signal (Column1). It is connected to fields 1711 and 1712. Transistor 1711 is also coupled to antenna element 1721 through a connection to patch 1731, while transistor 1712 is connected to antenna element 1722 through a connection to patch 1732.

In an initial approach to implement a matrix drive circuit on a cylindrical feed antenna with unit cells arranged in a non-regular grid, two steps are performed. In the first step, the cells are placed on concentric rings and each of the cells is connected to a transistor placed next to the cell and acting as a switch to drive each cell individually. In the second step, the matrix drive circuitry is configured to connect every transistor with a unique address, as required by the matrix drive approach. Although the matrix drive circuit (similar to LCDs) is made up of row and column traces, because the cells are placed in rings, there is no systematic way to assign a unique address to each transistor. This mapping problem results in a very complex network to cover all transistors and a significant increase in the number of physical traces to perform routing. Because of the high density of cells, these traces interfere with the antenna's RF performance due to coupling effects. Additionally, due to the complexity and high packing density of the traces, routing of the traces cannot be achieved by commercially available layout tools.

In one embodiment, the matrix drive circuitry is predefined before the cells and transistors are placed. This ensures the minimum number of traces needed to drive all cells, each with a unique address. This strategy reduces the complexity of the drive circuitry and simplifies routing, which subsequently improves the RF performance of the antenna.

More specifically, in one approach, in a first step, cells are placed on a regular rectangular grid made up of rows and columns that describe the unique address of each cell. In the second step, cells are grouped and transformed into concentric circles while maintaining connections and addresses to rows and columns as defined in the first step. The purpose of this transformation is not only to place the cells on the rings, but also to keep the distance between the cells and the distance between the rings constant over the entire aperture surface. To achieve this goal, several methods exist for grouping cells.

In one embodiment, a TFT package is used to enable unique addressing and placement within the matrix drive. Figure 18 shows one embodiment of a TFT package. Referring to Figure 18, a TFT and hold capacitor 1803 is shown with input and output ports. There are two input ports connected to traces 1801 and two output ports connected to traces 1802 to connect the TFTs together using rows and columns. In one embodiment, the row and column traces intersect at a 90° angle to reduce and potentially minimize coupling between the row and column traces. In one embodiment, the row and column traces are on different layers.

Exemplary System Embodiment

In one embodiment, combined antenna apertures are used in a television system operating in conjunction with a set top box. For example, in the case of a dual receiving antenna, the satellite signals received by the antenna are provided to a set-top box of the television system (eg, a DirecTV receiver). More specifically, combined antenna operation can simultaneously receive RF signals at two different frequencies and/or polarizations. In other words, one sub-array of elements is controlled to receive RF signals at one frequency and/or polarization, while another sub-array is controlled to receive signals at another different frequency and/or polarization. It is controlled. These differences in frequency or polarization represent different channels received by the television system. Similarly, two antenna arrays can be controlled such that two different beam positions receive channels from two different locations (eg, two different satellites) to receive multiple channels simultaneously.

Figure 19 is a block diagram of one embodiment of a communication system that performs simultaneous dual reception in a television system. Referring to FIG. 19, antenna 1401 has two spatially interleaved antenna apertures that are independently operable to perform dual reception simultaneously at different frequencies and/or polarizations as described above. ) includes. Note that although only two spatially interleaved antenna operations are mentioned, a TV system may have three or more antenna apertures (eg, 3, 4, 5, etc.).

In one embodiment, an antenna 1401 comprising two interleaved slotted arrays is connected to a diplexer 1430. This connection may include one or more feeding networks that receive signals from elements of the two slotted arrays to generate two signals that are fed into the diplexer 1430. In one embodiment, diplexer 1430 is a commercially available diplexer (e.g., model PB1081WA Ku-band sitcom diplexor from A1 Microwave).

Diplexer 1430 is connected to a pair of low noise block down converters (LNBs) 1426 and 1427, which provide a noise filtering function and a down conversion function in a manner known in the art. function) and amplification. In one embodiment, LNBs 1426 and 1427 reside within an outdoor unit (ODU). In another embodiment, LNBs 1426 and 1427 are integrated into the antenna device. LNBs 1426 and 1427 are connected to set top box 1402, which is connected to television 1403.

The set-top box 1402 includes analog-to-digital converters (ADCs) 1421 and 1422 connected to the LNBs 1426 and 1427 to convert the two signals output from the diplexer 1430 into digital format. ) includes pairs of

Once converted to digital format, the signals are demodulated by demodulator 1423 and decoded by decoder 1424 to obtain encoded data on the received waves. Afterwards, the decoded data is sent to the controller 1425, which sends it to the television 1403.

Controller 1450 controls antenna 1401 including interleaved slotted array elements of both antenna apertures on a single combined physical aperture.

Example of Full Duplex Communication System

In another embodiment, combined antenna apertures are used in a full duplex communications system. Figure 20 is a block diagram of another embodiment of a communication system with simultaneous transmit and receive paths. Although only one transmit path and one receive path are shown, the communication system may include two or more transmit paths and/or two or more receive paths.

Referring to FIG. 20, antenna 1401 includes two spatially interleaved antenna arrays operable independently to simultaneously transmit and receive at different frequencies, as described above. In one embodiment, antenna 1401 is connected to diplexer 1445. The connection may be by one or more feeding networks. In one embodiment, in the case of a radial feed antenna, diplexer 1445 combines two signals, and the connection between antenna 1401 and diplexer 1445 carries both frequencies. It is a single broadband feeding network that can

The diplexer 1445 is connected to low noise block down converters (LNBs) 1427, which perform noise filtering functions, down conversion functions, and amplification in manners known in the art. In one embodiment, LNB 1427 resides within an outdoor unit (ODU). In another embodiment, LNB 1427 is integrated into the antenna device. LNB 1427 is coupled to modem 1460, which is coupled to computing system 1440 (e.g., computer system, modem, etc.).

The modem 1460 includes an analog-to-digital converter (ADC) 1422 connected to the LNB 1427 to convert the received signal output from the diplexer 1445 into a digital format. Once converted to digital format, the signals are demodulated by demodulator 1423 and decoded by decoder 1424 to obtain encoded data on the received waves. The decoded data is then sent to controller 1425, which sends it to computing system 1440.

Modem 1460 also includes an encoder 1430 that encodes data to be transmitted from computing system 1440. The encoded data is modulated by a modulator 1431 and then converted to analog by a digital-to-analog converter (DAC) 1432. Afterwards, the analog signal is filtered by an up-convert and high pass amplifier (BUC) 1433 and provided to one port of the diplexer 1445. In one embodiment, BUC 1433 resides within an outdoor unit (ODU).

Diplexer 1445, operating in a manner known in the art, provides a transmit signal to antenna 1401 for transmission.

Controller 1450 controls antenna 1401 comprising two arrays of antenna elements on a single combined physical aperture.

Note that the full duplex communication system shown in FIG. 20 (including software updates) has numerous applications including, but not limited to, Internet communication, vehicle communication, etc.

Some portions of the foregoing detailed description are presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and expressions are means used by those skilled in the art of data processing to most effectively convey the essence of the work to others skilled in the art. An algorithm is generally considered herein to be a self-consistent sequence of steps that lead to a desired result. These steps are those that require physical manipulations of physical quantities. Typically, although not necessarily, these quantities take the form of electrical or magnetic signals that can be stored, transmitted, combined, compared, and otherwise manipulated. It has sometimes proven convenient to refer to these signals as bits, values, elements, symbols, letters, terms, numbers, etc., primarily for reasons of common usage.

However, it should be kept in mind that all of these and similar terms relate to appropriate physical quantities and are simply convenient labels applied to those quantities. Unless explicitly and specifically stated otherwise in the discussion below, throughout this application the terms "processing" or "computing" or "calculating" or "determining" or " Discussions using terms such as "displaying" or the like refer to manipulating data represented as physical (electronic) quantities within the registers and memories of a computer system to store, transmit, or store such information. It is understood to refer to the operations and processes of a computer system or similar electronic computing device that converts other data into similarly represented physical quantities within display devices.

The invention also relates to apparatus for performing the operations herein. Such devices may be specially configured for the required purpose, or may include a general purpose computer that is selectively activated or reconfigured by a computer program stored on the computer. This computer program can be used on any type of disk, including floppy disks, optical disks, CD-ROMs, and magnetic-optical disks, read-only memories (ROMs), and random RAMs (RAMs). access memories), EPROMs, EEPROMs, magnetic or optical cards, or any type of medium suitable for storing electronic instructions, each Can be connected to a computer system bus.

The algorithms and displays presented herein are not inherently related to any particular computer or other device. A variety of general purpose systems may be utilized with programs according to the teachings herein, or it may prove convenient to construct more specialized equipment to perform the necessary method steps. The required architecture for a variety of these systems will appear in the description below. Moreover, the present invention has not been described in connection with any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the invention as described herein.

Machine-readable medium includes any mechanism for storing or transmitting information in a form readable by a machine (e.g., computer). For example, machine-readable media may include read only memory (ROM); RAM (random access memory); magnetic disk storage media; Gwanghang storage media; flash memory devices; Includes etc.

Although numerous modifications and variations of the invention will no doubt become apparent to those skilled in the art after reading the foregoing description, it should be understood that any particular embodiment shown and described by way of example is in no way intended to be limiting. . Therefore, references to details of various embodiments are not intended to limit the scope of the claims, which by themselves recite only those features believed to be essential to the invention.

Claims (29)

As an antenna,
Antenna feed inputting feed wave;
an antenna element array having a plurality of metamaterial surface elements, each antenna element having a liquid crystal (LC) structure to operate as an active element controlling resonance within each antenna element; and
A controller that controls which of the metamaterial surface elements are turned on and which are turned off by controlling the LC within each metamaterial surface element, wherein the LC within each antenna element is configured to transmit energy from the feed wave. a controller operating as an on/off switch, wherein the metamaterial surface elements are controlled and operable together to form a beam for a frequency band for use in holographic beam steering,
The LC structure is adapted to laterally function with at least one of a proton, hydrogen (H), or heteroatom, as follows:

A mixture having one or more of the following, wherein A, B, Rx, Ry and Rz are one or more chemical elements. Or represents a compound, Y and Z represent a single bond or triple bond, m represents an integer, A is a saturated carbon chain, alkoxy (OC _n H _(2n+1) ), cyclohexyl or phenyl moiety (phenyl moiety), B is a second alkyl, alkoxy chain or polar group, Rx, Ry and Rz are each an alkyl group, where n is equal to an integer.
The antenna of claim 1, wherein the hetero atom includes at least one selected from the group consisting of fluorine (F), bromide (Br), or chlorine (Cl).
The antenna of claim 1, wherein Rx, Ry and Rz comprise one or more alkyl groups.
4. The method of claim 3, wherein the one or more alkyl groups are methyl (CH ₃ )ethyl (CH ₂ CH ₃ ), propyl (CH ₂ CH ₂ CH ₃ ), or methoxy (OCH ₃ ), ethoxy (OCH ₂ CH ₃ ). , propoxy (OCH ₂ CH ₃ ), or trifluoromethoxy (OCF ₃ ).
The antenna of claim 1, wherein A is any one of a saturated carbon chain, alkoxy (OC _n H _(2n+1) ), cyclohexyl, or phenyl moiety.
The antenna of claim 1, wherein B is any one of a second alkyl, an alkoxy chain, or a polar group.
7. The method of claim 6, wherein the polar group is a hetero atom, cyano (CN) or isothiocyanate (NCS), trifluoromethoxy (OCF ₃ ), cyano (CN), bromide (Br) or tifluoro. An antenna comprising phenyl (C ₆ H ₂ F ₃ ).
2. The antenna of claim 1, wherein the mixture includes one or more of the following:

where D is CH ₂ , O, S or Se; R1-R12 are the same as C _n H _(2n+1) , H, F, Cl, SC _n H _(2n+1) , SeC _n H _(2n+1) or Br; X is equal to NCS, F, Br, Cl or H, and n is an integer.
The antenna of claim 8, wherein n is 1 to 7.
The antenna of claim 8, wherein D is one carbon and two hydrogens, X is the same as NCS, and n is the same as 4 in structures 1.
The antenna of claim 8, wherein D is one oxygen and two hydrogens, X is the same as NCS, and n is the same as 4 in structures 1.
The antenna of claim 8, wherein X is equal to NCS in structure 2.
9. The antenna of claim 8, wherein X is identical to NCS in structure 3.
9. The antenna of claim 8, wherein X is identical to NCS in structure 4.
9. The antenna of claim 8, wherein X is identical to NCS in structure 5.
9. The antenna of claim 8, wherein X is identical to NCS in structure 6.
According to paragraph 1,
the feed wave propagates concentrically from the antenna feed;
The antenna is
plurality of slots;
further includes a plurality of patches,
Each of the patches is placed together on one slot among the plurality of slots using LC cells and is separated from one slot among the plurality of slots using the LC cells to form a patch/slot pair, An antenna wherein each patch/slot pair is turned off or on based on the application of a voltage to the pair of patches specified by the control pattern.
2. The method of claim 1, wherein the metamaterial surface elements are part of a tunable slot array comprising a plurality of slots, each slot being tuned to provide desired scattering at a given frequency, and wherein the elements within the tunable slot array comprise one or more rings. An antenna characterized in that it is located at.
As an antenna,
Antenna feed inputting feed wave;
An antenna element array having a plurality of metamaterial surface elements, each metamaterial surface element having a liquid crystal (LC) structure for operating as an active element that controls resonance within each antenna element; and
A controller that controls which of the metamaterial surface elements are turned on and which are turned off by controlling the LC within each metamaterial surface element, wherein the LC within each antenna element is configured to transmit energy from the feed wave. a controller operating as an on/off switch, wherein the metamaterial surface elements are controlled and operable together to form a beam for a frequency band for use in holographic beam steering,
The LC structure comprises a mixture having voltage tunable RF dielectric anisotropy with optical Δη ≥ 0.3 and RF Δε ≥ 1.33, wherein the mixture comprises the following compounds:


Having two or more of the following and being laterally functional with at least one of a proton, hydrogen (H), or heteroatom:

wherein A, B, Rx, Ry and Rz represent one or more chemical elements or compounds, Y and Z represent a single or triple bond, m represents an integer, and A is a saturated carbon chain, alkoxy (OCnH _(2n+1) ), cyclohexyl or phenyl moiety, B is a second alkyl, alkoxy chain or polar group, Rx, Ry and Rz are each an alkyl group, where n is An antenna characterized by something like an integer.
20. The antenna of claim 19, wherein the mixture comprises at least 7 compounds.
20. The antenna of claim 19, wherein the mixture comprises at least 8 compounds.
20. The antenna of claim 19, wherein the mixture comprises 9 compounds.
20. The antenna of claim 19, wherein the mixture includes at least 11.7h, 11.7i and 111.7h.
24. The antenna of claim 23, wherein the mixture also includes at least 111.7n and 111.7o.
24. The antenna of claim 23, wherein the mixture also comprises at least 4TOLCl or FNCST1.
According to clause 19,
the feed wave propagates concentrically from the antenna feed;
The antenna is:
plurality of slots;
further includes a plurality of patches,
Each of the patches is placed together on one slot among the plurality of slots using LC cells and is separated from one slot among the plurality of slots using the LC cells to form a patch/slot pair, An antenna wherein each patch/slot pair is turned off or on based on the application of a voltage to the pair of patches specified by the control pattern.
20. The antenna of claim 19, wherein the antenna elements are controlled and operable together to form a beam for a frequency band for use in holographic beam steering.
20. The method of claim 19, wherein the metamaterial surface elements are part of a tunable slot array comprising a plurality of slots, each slot being tuned to provide desired scattering at a given frequency, wherein the elements within the tunable slot array comprise one or more rings. An antenna characterized in that it is located at. delete