KR20230072509A - 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 comprises an antenna comprising an antenna element array having a plurality of antenna elements, each antenna element having a liquid crystal (LC) structure, wherein the LC structure comprises at least a proton of: and one or more mixtures adapted to function laterally with one or more of hydrogen (H) or heteroatoms.

Description

Antennas with radio frequency liquid crystal (RFLC) mixtures with high RF tuning, wide thermal operating range and low viscosity

preference

This patent application is filed on May 20, 2016, titled "High RF Tuning, Wide Thermal Operating Range, and Low Viscosity High Frequency Liquid Crystal (RFLC) Mixtures," filed on May 20, 2016, in response to corresponding U.S. Provisional Patent Application Serial No. 62/339,550. Priority is claimed, which 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 having high RF tuning and low viscosity suitable for use in metamaterial-tuned antennas.

Recently, surface scattering antennas and other high frequency devices using liquid crystal (LC) based metamaterial elements as part of the device have been disclosed. In the case of antennas, LCs have been used as part of an 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 having 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 comprises an antenna comprising an antenna element array having a plurality of antenna elements, each antenna element having a liquid crystal (LC) structure, the LC structure comprising one of the following:

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

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

A radio frequency (RF) device comprising a liquid crystal (LC) mixture and methods of using the same are disclosed. In one embodiment, an RF device may include an antenna, phased array, or light modulator. In one embodiment, the LC mixture is a Radio Frequency Liquid Crystal (RFLC) mixture comprising pi-conjugated mesogenic (liquid crystal) compounds. In one embodiment, the RFLC is a mixture suitable for use as the active element of a meta network antenna technology. To be useful in metanetworks antenna technology, the RFLC mixture has a large voltage tunable RF dielectric anisotropy (optical Δη ≥ 0.3, RF Δε ≥ 1.33), acceptable temperature stability characteristics (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 as Δn > 0.3 in the field. These include: 1) antenna applications such as holographic antennas based on resonant elements, reflection-arrays and phased arrays; and 2) spatial light modulators, such as, for example, those used in light imaging detection and ranging (LIDAR). 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 blend 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 typically it is accompanied by increased viscosity and high melting point. These materials enable the operation of the antenna active element and thus the construction of the antenna array.

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 below, clearing point > 125°C); 4) Provides reasonable RF losses (Δε/Tanδ ≥ 75). This combination of characteristics is relatively unique. Any of these properties can be specifically optimized. However, it is much more difficult to implement a material that simultaneously meets all requirements. Therefore, these materials (mixtures) and design strategies are inherently unique and valuable.

Most liquid crystals in commercial use do not have a single molecular structure. They are composed of a mixture 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. This same structure/property relationship is used simultaneously to create a condensed phase (liquid crystal mesophase) that satisfies all operating requirements.

The embodiments of the present invention not only provide specific chemical “recipes” for useable 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 chemical structure can be used in multiple mixture “recipes” to tailor specific chemical and physical properties. The general structure/property relationship demonstrated can be used to design new materials with significantly improved performance properties.

In one embodiment, the highly birefringent liquid crystals disclosed herein produce a large length/width polarization anisotropy at the molecular level. In one embodiment, this is achieved by creating a long, rigid π-electron bonded core (eg, tolane). As such (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 the 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 ) are used to further increase birefringence and introduce permanent dipoles.

This idea can be expressed through the above generic structures (GS 1, GS 2, GS 3 and GS 4). For GS 1, GS 2 and GS 4, cores are 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 ) may also be introduced at various R positions. This lateral functionalization disfavors smectic phase formation and/or modifies intermolecular interactions to modify the rotational viscosity γ, the elastic constant κ and the melting point T _m . Lengthening the core (increasing m) generally increases birefringence. In this case, A is a saturated carbon chain, or an alkoxy (OCnH(2n+1)), or a similarly functionalized cyclohexyl and/or phenyl moiety (phenyl moiety) as shown in Structures 1-6 below. am. The longer the carbon chain, the lower the melting point in general. In this case, B is a second compound such as isothiocyanate (NCS), trifluoromethoxy (OCF ₃ ), cyano (CN), bromide (Br) or trifluorophenyl (C ₆ H ₂ F ₃ ). an alkyl or alkoxy chain or polar group. Structure GS 3 illustrates a complementary structural motif in which Z and Y independently represent single or triple bonds.

Create a liquid crystal mixture

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

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 1-6 are liquids at room temperature. To be liquid crystal, the mixture must be a liquid within a useful operating temperature range. By weighing specific amounts of each compound, mixing them together, and then heating them until the compounds melt and mix together to form a liquid at room temperature, the general structures GS 1, GS 2, GS 3 and specific structures 1-6 are shown. 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 lengths of carbon chains (n = 1-7), or as complex as adding many different structures at varying weight percentages.

1-6 and/or GS 1 / GS 2 may differ not only in terms of physical properties, but also in terms of birefringence Δn. Thus, mixtures containing different weight percentages will also have different optical properties. For 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 denotes the number of carbons in the saturated hydrocarbon tail. The number of carbons generally varies between n = 1 and n = 7, 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 carbon and 2 hydrogens (with an extra carbon added), X = NCS and n = 4. In this case, structure number 1 is named pentyl-cyclohexylphenyl isocyanate. If the same basic structure is maintained and D is changed to oxygen, the structure is named as 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 embodiment, when D = CH2 and X = NCS, structure number 2 is named pentyl-isothiocyanato tolein.

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

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

Structure 5 is referred to herein as phenyl-bis-tolein. It has two triple bonds between the phenyl group and the other phenyl ring. In one embodiment, D = CH2 and X = NCS. In this case, structure 5 is named pentyl-isothiocyanto phenyl-bistolein.

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-isothiocyanto 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 Δf)

As mentioned above, useful liquid crystal mixtures are prepared by combining a number of unique basic structures (LC monoliths) in varying weight percentages. Scheme 2 shows a library of LC monoliths that was comprehensively prepared for this work. Table 1 shows the thermal properties of the LC monolith shown in Scheme 2. The term “melt” is used to denote the melting point, ie, 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 re-occurs (renews) 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 opalescent in appearance to transparent). From the examination of Table 1, the lowest melting LC monolith, 4TOLC1, 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 the various mixtures prepared using the library of compounds. The weight percentages of each compound used are given, and the resulting thermal and tuning properties are given.

That mixtures can be prepared using the LC monolith shown in Scheme 2 that freezes as low as -64°C and clears as high as 153°C can be further illustrated by the inspection of Table 2. These values are comparable to the widest nematic temperature range reported so far.

1 and 2 (a) to (c) show the concept of tuning related to the meta network antenna technology. This concept is best described in terms of one single element among many that constitutes an antenna based array of meta network elements, according to one embodiment. Nematic-phase liquid crystal mixtures, such as those discussed herein, are embedded within a single element of meta-network antenna technology. Figure 1 shows a representation of the relative orientation of the LC nematic phase to the incident microwave radiation. When an electric field is applied, the LC changes its direction and thus produces, via its Δn, Δf corresponding to the equation given in Figure 1. This Δf determines the behavior of the antenna technology.

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

Figure 3 shows approximate results from RF tuning studies 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 result, a Δn of ~0.4 must be reached to tune 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 of the mixture given in Table 2, but it also indicates the narrowest nematic temperature range. To address this, several new mixtures were investigated. The most successful mixture to date has been 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 somewhat increased viscosity, but the increase is not dramatic. To solve this, the amount of 5CHBT can be increased without significant decrease in Δn. Bulk testing at -20°C indicates that 13.8 remains 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, so does the RF loss for the mixtures shown here. However, in the case of 13.8, this loss is acceptable for the metanetwork antenna technique.

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

The aforementioned LC may be included in antenna embodiments having the following characteristics.

Examples of Antenna Embodiments

The techniques described above may 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, a 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 arranged in rows and columns. In one embodiment, the elements are arranged in rings.

In one embodiment, an antenna aperture having one or more arrays of antenna elements consists of a plurality of interconnected segments. When connected together, the combination of segments form 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 communication satellite earth stations are described. In one embodiment, the antenna system operates on a mobile platform (e.g., air, marine, land, etc.) operating using Ka-band frequencies or Ku-band frequencies for commercial 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 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 shape and steer the beams (such as phased array antennas).

In one embodiment, the antenna system consists of three functional subsystems: (1) a wave guiding structure consisting of 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 to command the formation of a tunable radiation field (beam) from metamaterial scattering elements using holographic principles.

Examples of Waveguide Structures

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 fashion from the feed point. In other words, a cylindrically fed antenna 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 produces an inward traveling feed wave. In this case, the feed wave most naturally emerges from the circular structure.

10 shows an aperture with one or more arrays of antenna elements disposed in concentric rings around the input feed of the antenna that is cylindrically fed.

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 in the antenna system is part of a unit cell consisting of a lower conductor, a dielectric substrate, and an upper conductor, the upper conductor Embodies a complementary electric inductive-capacitive resonator ("complementary electric LC" or "CELC") that is etched or deposited in the top conductor. As can be understood by those skilled in the art, LC in the context of CELC refers to inductance minus capacitance as opposed to liquid crystal.

In one embodiment, a 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, liquid crystal is encapsulated within each unit cell, separating the bottom conductor associated with the slot from the top conductor associated with the patch. A liquid crystal has a permittivity that is a function of the orientation of molecules comprising the liquid crystal, and the orientation (and thus permittivity) of the molecules can be controlled by adjusting the bias voltage across the liquid crystal. Using this property, in one embodiment, the liquid crystal incorporates an on/off switch for the transfer of energy from a guided wave to the CELC. When switched on, the CELC emits the same electromagnetic waves as an electrically small dipole antenna. Note that the teachings herein are not limited to having liquid crystals operate 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 positioned at a forty-five degree (45°) angle to the vector of the wave in the wave feed. Note that other positions (eg, at a 40° angle) may be used. This positioning of the elements enables 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 4 scattering elements per wavelength, the elements in a 30 GHz transmitting antenna will be approximately 2.5 mm (ie, 1/4 of a 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 characteristics at once. Rotating one set by 0 degrees and the other by 90 degrees will achieve the perpendicular goal, but not 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 within a single structure from both 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 capacitance and thus the resonant frequency of the individual elements to achieve 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 a threshold voltage and a saturation voltage. It does not lead to major sympathy. These two characteristic parameters can be different for different liquid crystal mixtures.

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

In one embodiment, the control structure for the antenna system has two major components: the antenna array controller, including the drive electronics, for the antenna system resides beneath the wave scattering structure, while the matrix drive 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 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 off-the-shelf LCD controls.

In one embodiment, the antenna array controller also includes a microprocessor running 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 heading information to the processor. may contain Position and heading 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 levels they are turned on at the frequency of operation. The elements are selectively detuned for frequency operation by application of a voltage.

For transmission, the controller supplies an array of voltage signals to the RF patches to create a modulation or control pattern. The control pattern causes the elements to be put into different states. In one embodiment, multistate control is used, where various elements are turned on and off at various levels, and a square wave (i.e., a sinusoidal gray shade modulation pattern) is used. 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 elements not radiating, some elements radiate more strongly than others. Variable radiation is achieved by applying specific voltage levels that adjust the liquid crystal permittivity by varying amounts, thereby variably detuning the elements and causing some elements to radiate more than others.

The generation of a focused beam by a metamaterial array of elements can be explained by the phenomena of constructive and destructive interference. Individual electromagnetic waves add up if they have the same phase when they meet in free space (constructive interference), and waves cancel each other if they have opposite phases when they meet in free space (destructive interference). If the slots of a slotted antenna are arranged such that each successive slot is placed at a different distance from the excitation point of the guided wave, the scattered wave from that element is the same as that of the previous slot. It will have a different phase than the scattered wave. If the slots are spaced apart by a quarter of the guided wavelength, each slot will scatter the wave with a 1/4 phase lag from the previous slot.

By using an array, the number of patterns of constructive and destructive interference that can be created is such that, using the principles of holography, the beams can travel in any direction theoretically plus or minus 90 degrees (90°) 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 and , 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 location 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 a satellite and to decode signals and to form transmit beams aimed towards the satellite. In one embodiment, the antenna systems are analog systems as opposed to antenna systems that employ digital signal processing to electrically shape and steer the beams (such as phased array antennas). In one embodiment, the antenna system is considered to be a "surface" antenna that is planar and relatively low profile, especially when compared to a conventional satellite dish receiver.

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 direct the antenna in a desired direction. Each of the tunable slots can be tuned/adjusted by changing the voltage across the liquid crystal.

The control module 1280 is coupled to the reconfigurable resonator layer 1230 for modulating the array of tunable slots 1210 by changing the voltage across the liquid crystal of FIG. 11 . The 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 (eg, multiplexer) to drive array of tunable slots 1210 . In one embodiment, the control module 1280 receives data including specifications for a holographic diffraction pattern to be driven onto the array of tunable slots 1210 . Holographic diffraction patterns can be generated in response to a spatial relationship between an antenna and a satellite such that the holographic diffraction pattern steers the downlink beams (uplink beams if the antenna system is performing transmission) in the 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 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). 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 the array of tunable slots 1210 such that the feed wave is steered into the desired RF beam (having the desired shape and direction). In other words, the feed wave encountered with the holographic diffraction pattern reconstructs the object beam 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, the radiant patch 1211 is co-located with the iris 1212 .

13 shows a cross-sectional view of one embodiment of a physical antenna aperture. The antenna aperture 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 FIG. 13 includes the plurality of tunable resonators/slots 1210 of FIG. 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.

The reconfigurable resonator layer 1230 also includes a gasket layer 1232 and a patch layer 1231 . A 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. The iris layer 1233 can be other types of substrates.

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

The patch layer 1231 may also be a PCB including metal like the radiation patches 1211 . In one embodiment, gasket layer 1232 includes spacers 1239 that provide a mechanical standoff to form a 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 noted above, in one embodiment, the antenna aperture of FIG. 13 includes a plurality of tunable resonators/slots, and the tunable resonator/slot 1210 is the patch 1211, liquid crystal 1213 of FIG. , and an iris 1212. A chamber for liquid crystal 1213 is defined by spacers 1239 , an iris layer 1233 , and a metal layer 1236 . When the chamber is filled with liquid crystal, the patch layer 1231 may be laminated onto the spacers 1239 to seal the liquid crystal within the resonator layer 1230 .

에 따라 변하고, 여기서 f는 슬롯(1210)의 공진주파수이고, L 및 C는 각각 슬롯(1210)의 인덕턴스 및 커패시턴스이다. 슬롯(1210)의 공진주파수는 도파관을 통해서 전파되는 피드파(1205)로부터 복사되는 에너지에 영향을 미친다. 예로서, 만일 피드파(1205)가 20 GHz라면, 슬롯(1210)이 피드파(1205)로부터의 아무런 에너지와도 실질적으로 결합되지 않도록 슬롯(1210)의 공진주파수가(커패시턴스를 변화시킴으로써) 17 GHz로 조정될 수 있다. 아니면, 슬롯(1210)이 피드파(1205)로부터의 에너지와 결합하고 에너지를 자유공간으로 복사하도록 슬롯(1210)의 공진주파수가 20 GHz로 조정될 수 있다. 주어진 예들은 두 부분(완적히 복사하거나 전혀 복사하지 않음)으로 이루어지지만, 슬롯(1210)의 리액턴스 및 이로 인한 공진주파수의 풀 그레이 스케일 제어(full gray scale control)가 다중 값 범위(multi-valued range)에 대해 전압 변동(voltage variance)을 가지고 가능하다. 그래서, 각각의 슬롯(1210)으로부터 복사되는 에너지는 상세한 홀로그래픽 회절 패턴들이 동조가능한 슬롯들의 어레이에 의해 형성될 수 있도록 정교하게 제어될 수 있다.The voltage between the patch layer 1231 and the iris layer 1233 can be modulated to tune the liquid crystal in the gap between the patch and slots (eg, tunable resonator/slot 1210). Adjusting the voltage across liquid crystal 1213 changes the capacitance of the slot (eg, tunable resonator/slot 1210). Thus, the reactance of a slot (eg, tunable resonator/slot 1210) can be varied by changing the capacitance. The resonant frequency of slot 1210 can also be calculated from the equation

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 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 (by changing the capacitance) is 17 so that the slot 1210 couples virtually no energy from the feed wave 1205 Can be tuned to GHz. Alternatively, the resonant frequency of the slot 1210 can be tuned to 20 GHz so that the slot 1210 couples with energy from the feed wave 1205 and radiates the energy into free space. Although the examples given are of two parts (either completely or not at all), the full gray scale control of the reactance of slot 1210 and thus its resonant frequency is multi-valued range. ) with a voltage variance. Thus, the energy radiated from each slot 1210 can be precisely controlled so 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 λ/2 from the nearest tunable slot in an adjacent row, so that commonly oriented tunable slots in different rows are spaced λ/4 apart; Other spacings 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.

Embodiments are described in U.S. Patent Application Serial No. 14/550,178, filed on November 21, 2014, entitled "Dynamic Polarization and Coupling Control from a Steerable Cylindrically Fed Holographic Antenna" and entitled "Ridged Waveguide Feed Structures for U.S. patent application Ser. No. 14/610,502, filed Jan. 30, 2015, "Reconfigurable Antenna" uses reconfigurable metamaterial technology.

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 exemplary 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 a portion of the first iris board layer with locations corresponding to slots. Referring to FIG. 14A , the circles are open areas/slots in the metallization on the bottom side of the iris substrate, 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. 14b shows a portion of the second iris board layer that includes slots. 14c shows patches over a portion of the second iris board layer. 14D shows a top view of a portion of a slotted array.

15 shows a side view of one embodiment of a cylindrically fed antenna structure. The antenna uses a double-layer feed structure (ie, two layers of the feed structure) to generate an inwardly traveling wave. In one embodiment, the antenna includes a circular outer shape, although this is not required. In other words, non-circular inward traveling structures may 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 a field at a lower level of the antenna. In one embodiment, coaxial pin 1601 is a commercially available 50Ω coaxial pin. Coaxial pin 1601 is connected (eg bolted) to the bottom of the antenna structure, which is a conducting ground plane 1602 .

Apart from the conductive ground plane 1602, it 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 can be λ/2, where λ goes at the frequency of operation. is the wavelength of the wave

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

Over the interstitial conductor 1603 is a dielectric layer 1605. 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 30%. In one embodiment, the range of refractive indices suitable for beamforming is 1.2-1.8, where free space has a refractive index equal to 1 by definition. Other dielectric spacer materials can be used to achieve this effect, for example plastic. It should be noted that materials other than plastics may be used as long as they achieve the desired waves that are effective. Alternatively, materials with distributed structures such as, for example, periodic sub-wavelength metallic structures that can be machined or lithographically delineated are dielectrics. (1605).

Above the dielectric 1605 is an RF-array 1606 . In one embodiment, the distance between the interstitial conductor 1603 and the RF-array 606 is 0.1-0.15". In another embodiment, this distance may be Aeff/2, where Aeff is within the medium at the design frequency. is the effective wavelength.

The antenna includes sides 1607 and 1608. The sides 1607 and 1608 allow the traveling wave feed from the coaxial pin 1601 to form an interstitial conductor 1603 from the area under the interstitial conductor 1603 (spacer layer) through reflection. It is angled to cause it to propagate into the region above (the dielectric layer). 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 a continuous radius to achieve the reflection. 15 shows angled sides with an angle of 45 degrees, other angles may be used to achieve signal transmission from the lower level feed to the 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 help transfer 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 go around the dielectric layer, the interstitial conductor, and the spacer layer. The same two steps are at the other ends of these layers.

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

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

16 shows another embodiment of an antenna system with outgoing waves. Referring to FIG. 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 (eg, resistors) are coupled together to two ground planes 1610 and 1611 . A coaxial pin 1615 (e.g., 50Ω) feeds the antenna. The RF array 1616 is over the dielectric layer 1612 and the ground plane 1611 .

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

The cylindrical feed in both antennas of FIGS. 15 and 16 improves the service angle of the antenna. Instead of a plus or minus 45 degree angular azimuth (±45° Az) and a plus or minus 25 degree elevation (±25° El) service angle, in one embodiment, the antenna system has a 75 degree angle from the bore sight in all directions ( 75°) service angle. As with any beamforming antenna made up of multiple individual radiators, the overall antenna gain is dependent on the gains of the constituent elements, which themselves are angle-dependent. When using common radiating elements, the 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 about 6 dB is expected.

Embodiments of an antenna with a cylindrical feed 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; reducing sensitivity to fabrication and control errors by maintaining high beam performance with coarser controls (extended to simple binary control); Cylindrically oriented feed waves provide a more advantageous side lobe pattern than rectilinear feeds because they result in spatially varied 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

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

In one embodiment, each scattering element in the antenna system is part of a unit cell consisting of a bottom conductor, a dielectric substrate, and a top conductor, the top conductor being a complementary electrical inductive-capacitive resonator etched or deposited on the top conductor. ("complementary electric LC" or "CELC").

In one embodiment, liquid crystal (LC) is injected into the gap around the scattering element. Liquid crystal is encapsulated within each unit cell and separates the lower conductor associated with the slot from the upper conductor associated with the patch. A liquid crystal has a permittivity that is a function of the orientation of the molecules comprising the liquid crystal, and the orientation (and thus permittivity) of the molecules can be controlled by adjusting the bias voltage across the liquid crystal. Using this property, the liquid crystal acts as an on/off switch for the transfer of energy from the guided wave to the CELC. When switched on, the CELC emits electromagnetic waves like an electrical miniature 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 bottom and top conductors results in a 4x 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 in a manner known in the art to improve responsiveness so that the 7 millisecond (7 ms) requirement can be met.

The CELC element responds to a magnetic field 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 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 with the same frequency as the guided wave.

The phase of the electromagnetic wave generated by a single CELC can be selected by the position of the CELC on the vector of the guided wave. Each cell generates a wave in phase with the guided wave parallel to the CELC. Since the CELC is smaller than the wavelength, the output wave has the same phase as the guided wave when it passes under 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 to the vector of the wave in the wave feed. This position of the elements allows control of the polarization of free space waves generated from or received by the elements. In one embodiment, the CELCs are arranged with an element-to-element spacing less than the free-space wavelength of the antenna's operating frequency. For example, if there are 4 scattering elements per wavelength, the elements in a 30 GHz transmitting antenna will be approximately 2.5 mm (ie, 1/4 of a 10 mm free space wavelength at 30 GHz).

In one embodiment, a CELC is implemented as a patch antenna comprising a patch co-located over a slot with liquid crystal between the two. In this respect, metamaterial antennas act like slotted (scattering) waveguides. 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 over the cylindrical feed antenna aperture in a manner enabling a systematic matrix drive circuit. The arrangement of cells includes the arrangement of transistors for driving the matrix. Figure 17 shows one embodiment of the arrangement of matrix drive circuitry in relation to antenna elements. Referring to FIG. 17 , the row controller 1701 is connected to the transistors 1711 and 1712 through row select signals Row1 and Row2, respectively, and the column controller 1702 is connected to the transistors 1711 and 1712 through the column select signals Column1. are connected to s 1711 and 1712. Transistor 1711 is also connected 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 implementing a matrix drive network on a cylindrical feed antenna with unit cells arranged in a non-regular grid, two steps are performed. In a first step, the cells are arranged on concentric rings, and each of the cells is connected to a transistor that is placed next to a cell and acts as a switch to individually drive each cell. In a second step, the matrix drive circuitry is configured to connect to every transistor with a unique address, as the matrix drive approach requires. Since matrix drive circuitry is constructed by row and column traces (similar to LCDs) but cells are arranged on rings, there is no systematic way to assign a unique address to each transistor. This mapping problem results in a very complex circuitry to cover all transistors and a significant increase in the number of physical traces to perform routing. Due to the high density of cells, these traces hinder the RF performance of the antenna due to the coupling effect. Also, 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 cells and transistors are placed. This ensures the minimum number of traces needed to drive all of the cells, each with a unique address. This strategy reduces the complexity of the drive circuitry and simplifies routing, which in turn improves the RF performance of the antenna.

More specifically, in one approach, in a first step, cells are laid out on a regular rectangular grid of rows and columns describing each cell's unique address. In the second step, the cells are grouped and transformed into concentric circles while maintaining the addresses and connections to the 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 cells and between rings constant over the entire aperture. 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. 18 shows one embodiment of a TFT package. Referring to Fig. 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 row and column. In one embodiment, row and column traces intersect at a 90° angle to reduce and potentially minimize coupling between 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 dual receive antennas, satellite signals received by the antennas are provided to a set top box (eg, a DirecTV receiver) of a television system. 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 a different frequency and/or polarization. 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) in order to receive a plurality of channels simultaneously.

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 independently operable to perform simultaneous dual reception at different frequencies and/or polarizations as described above. ). Note that although only two spatially interleaved antenna operations are mentioned, a TV system may have three or more antenna apertures (eg, three, four, five, etc. antenna apertures).

In one embodiment, an antenna 1401 comprising two interleaved slotted arrays is coupled to a diplexer 1430. This connection may include one or more feeding networks that receive signals from elements of the two slotted arrays to produce two signals that are fed into diplexer 1430. In one embodiment, diplexer 1430 is a commercially available diplexer (eg, 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 in a manner known in the art, have a noise filtering function, a down conversion function function), and amplification. In one embodiment, LNBs 1426 and 1427 reside within an outdoor-door unit (ODU). In another embodiment, LNBs 1426 and 1427 are integrated into the antenna arrangement. LNBs 1426 and 1427 are connected to a set top box 1402 which is connected to a 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 formats. ) contains a pair of

Once converted to digital form, 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 television 1403.

Controller 1450 controls antenna 1401 comprising 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 communication system. 20 is a block diagram of another embodiment of a communication system having simultaneous transmit and receive paths. Although only one transmit path and one receive path are shown, a communication system may include more than one transmit path and/or more than one receive path.

Referring to FIG. 20, antenna 1401 includes two spatially interleaved antenna arrays that are independently operable for simultaneous transmission and reception at different frequencies as described above. In one embodiment, antenna 1401 is coupled 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 the two signals, and the connection between antenna 1401 and diplexer 1445 carries both frequencies. It is a single broad-band feeding network capable of

A diplexer 1445 is coupled to low noise block down converters (LNBs) 1427, which perform noise filtering functions, down conversion functions, and amplification in a manner known in the art. In one embodiment, LNB 1427 resides within an outdoor-door unit (ODU). In another embodiment, the LNB 1427 is integrated into the antenna device. LNB 1427 is coupled to modem 1460, which is coupled to computing system 1440 (eg, 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 form, the signals are demodulated by demodulator 1423 and decoded by decoder 1424 to obtain data encoded 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. Then, 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-door 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 many applications, including but not limited to internet communication, vehicle communication, and the like.

Some portions of the detailed description above are presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic statements and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is generally considered herein to be a self-consistent sequence of steps leading to a desired result. These steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like.

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

The invention also relates to apparatus for performing the operations herein. Such a device may include a general-purpose computer that is specially configured for the necessary purpose or that is selectively activated or reconfigured by a computer program stored on the computer. Such a computer program may be used on any type of disk, including floppy disks, optical disks, CD-ROMs, and magnetic-optical disks, read-only memories (ROMs), random RAMs (RAMs). access memories), EPROMs, EEPROMs, magnetic or optical cards, or any type of medium suitable for storing electronic instructions, each may 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 used with programs in accordance with the teachings herein, or it may prove convenient to construct more specialized apparatus to perform the necessary method steps. The required structure for a variety of these systems will appear in the description below. Moreover, the present invention has not been described in the context of 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.

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

While numerous modifications and variations of the present invention will undoubtedly 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 illustration is in no way intended to be considered limiting. . Therefore, references to details of various embodiments are not intended to limit the scope of the claims, which per se recite only those features deemed essential of the invention.

Claims (29)

As an antenna,
An antenna element array having a plurality of antenna elements, each antenna element having a liquid crystal (LC) structure, wherein the LC structure is one of the following

An antenna comprising at least one mixture adapted to function laterally with at least one of protons, hydrogen (H) or heteroatoms.
The antenna of claim 1, wherein the hetero atom includes at least one selected from the group consisting of fluorine (F), bromide (Br), and chlorine (Cl).
2. The antenna according to claim 1, wherein Rx, Ry and Rz comprise one or more alkyl groups.
4. The method of claim 3, wherein the at least one alkyl group is 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 ) An antenna characterized in that it comprises at least one selected from the group consisting of.
The antenna according to claim 1, wherein A is any one of a saturated carbon chain, an alkoxy (OC _n H _(2n+1) ), a cyclohexyl or a phenyl moiety.
The antenna according to claim 1, wherein B is any one of a second alkyl, alkoxy chain or polar group.
7. The method of claim 6, wherein the polar group is a heteroatom, cyano (CN) or isothiocyanate (NCS), trifluoromethoxy (OCF ₃ ), cyano (CN), bromide (Br) or trifluoro 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.

wherein 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, equal to F, Br, Cl or H, and n is an integer.
9. The antenna according to claim 8, wherein n is 1 to 7.
9. The antenna of claim 8, wherein D is one carbon and two hydrogens, X is equal to NCS, and n is equal to 4 in Structure 1.
9. The antenna of claim 8, wherein D is one oxygen and two hydrogens, X is equal to NCS, and n is equal to 4 in structure 1.
9. The antenna of claim 8 wherein D is the same and X is the same as NCS in structure 2.
9. The antenna of claim 8 wherein D is the same and X is the same as NCS in structure 3.
9. The antenna of claim 8 wherein D is the same and X is the same as NCS in structure 4.
9. The antenna of claim 8 wherein D is the same and X is the same as NCS in structure 5.
9. The antenna of claim 8 wherein D is the same and X is the same as NCS in structure 6.
According to claim 1,
an antenna feed that inputs a feed wave that propagates concentrically from the feed;
a plurality of slots;
Provide a plurality of patches,
Each of the patches is disposed at the same position on the plurality of slots using the LC cells and is separated from one of the plurality of slots using the LC cells to form a patch/slot pair, each An antenna characterized in that the patch/slot pair is turned off or turned on based on the application of a voltage to the patch of the pair specified by the control pattern.
2. The antenna of claim 1, wherein the antenna elements are controlled and operable together to form a beam for a frequency band for use in holographic beam steering.
2. The antenna elements of claim 1, wherein the antenna elements are part of a tunable slot array comprising a plurality of slots, each slot tuned to provide a desired scatter at a given frequency, the elements within the tunable slot array being located in one or more rings. An antenna characterized in that it is.
As an antenna,
An antenna element array having a plurality of antenna elements, each antenna element having a liquid crystal (LC) structure,
The antenna, characterized in that the LC structure comprises a mixture of two or more of the following compounds.

21. The antenna of claim 20, wherein the mixture comprises at least 7 compounds.
21. The antenna of claim 20, wherein the mixture comprises at least eight compounds.
21. The antenna of claim 20, wherein the mixture comprises nine or more compounds.
21. The antenna of claim 20 wherein the mixture comprises at least 11.7h, 11.7i and 11.1h.
25. The antenna of claim 24 wherein the mixture also includes at least 111.7n and 111.7o.
25. The antenna of claim 24 wherein the mixture also includes at least 4TOLC1 or FNCST1.
According to claim 20,
an antenna feed that inputs a feed wave that propagates concentrically from the feed;
a plurality of slots;
Provide a plurality of patches,
Each of the patches is disposed at the same position on the plurality of slots using the LC cells and is separated from one of the plurality of slots using the LC cells to form a patch/slot pair, each An antenna characterized in that the patch/slot pair is turned off or turned on based on the application of a voltage to the patch of the pair specified by the control pattern.
21. The antenna of claim 20, wherein the antenna elements are controlled and operable together to form a beam for a frequency band for use in holographic beam steering.
21. The antenna elements of claim 20, wherein the antenna elements are part of a tunable slot array comprising a plurality of slots, each slot tuned to provide a desired scatter at a given frequency, the elements within the tunable slot array being located in one or more rings. An antenna characterized in that it is.

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