antenna

antenna词根
-antenna一词来源于拉丁语antenna，指昆虫、甲壳类动物等的触角。

其词根ant-表示“前面”、“前进”、“对面”，也有“感觉”、“察觉”的意思。

因此，antenna指的就是昆虫等用来感知周围环境的器官。

- 在生物学领域，antenna还可以用来指代某些植物的触须或鳞片。

这些结构也有感知外部刺激的功能，与昆虫的触角类似。

- antenna这个词还在无线通讯领域中得到广泛应用。

天线（antenna）是无线通讯系统中的重要部件，用于接收和发送无线电波。

这里的ant-则是指“对面”、“相对”之意，意味着天线可以接收和发送来自对面的信号。

- 除了antenna，ant-这个词根还可以在其他单词中找到，比如antebellum（指战争前的时期）、antecedent（指前事或先例）、antagonist（指对抗者）、antedate（指提前日期）、antipathy（指厌恶或憎恶）等。

这些单词都带有“前面”、“相对”或“对抗”的意思，与ant-的词根含义相符。

- 1 -。

专利名称：ANTENNA发明人：USUI TAKESHI,KOBAYASHI ATSUSHI 申请号：JP10948691申请日：19910515公开号：JPH04337904A公开日：19921125专利内容由知识产权出版社提供摘要：PURPOSE:To enable assembly and manufacture with a little man-hour, to reduce the number of equipments and to enable reception over a wide frequency band. CONSTITUTION:An antenna element 3 formed by a metal plate is adhered and fixed to the inner face of a housing 1. A ground 4 formed by a metal plate is fitted, fixed to an opening part 2 of the housing 1 and arranged in counter to the antenna element 3 through a void 5. The antenna can be constituted by integrating the antenna element 3 and the ground 4, which are formed by the metal plates, into the housing 1. A ground 6 formed by the metal plate can be also used as the cover of the housing 1. The width of the void between the antenna element 3 and the ground 4 can be changed by bending the metal plate forming the ground 4 or the like, and the distribution of a dielectric constant between the antenna element 3 and the ground 4 can be adjusted by selecting the kind of resin forming the housing 1.申请人：MATSUSHITA ELECTRIC WORKS LTD更多信息请下载全文后查看。

专利名称：ANTENNA发明人：NISHIGORI MASABUMI,AIZAWA SHINICHI 申请号：JP10548791申请日：19910510公开号：JPH04334201A公开日：19921120专利内容由知识产权出版社提供摘要：PURPOSE:To easily change over a receiving frequency band by providing a changeover switch which opens/closes the connection of duplicate antenna element so as to change over a frequency characteristic. CONSTITUTION:A base part 1 incorporates a printed board and mounts a coil 4, a capacitor 5 and a transformer 6 for impedance conversion, which constitute an LC resonance circuit. The changeover switch 7 changing over the frequency characteristic by opening/closing the connection of the two antenna elements. That is, the two antenna elements, the coil 4, the capacitor 5 and the changeover switch 7 are connected so as to form a closing loop. Then, receiving sensitivity is upgraded with regard to a VHF low band by turning off (LOW side) the changeover switch 7 and receiving sensitivity is upgraded with regard to a VHF high band and a UHF band by turning it on (HI side). Consequently, the frequency characteristic of an antenna changes so as to change over the receiving frequency band.申请人：NISHIKIORI:KK更多信息请下载全文后查看。

专利名称：ANTENNA发明人：IWAI TORU,IKEDA JUNICHI 申请号：JP29852290申请日：19901102公开号：JPH04170805A公开日：19920618专利内容由知识产权出版社提供摘要：PURPOSE:To favorably execute installing work and maintenance work, and simultaneously, to easily obtain an expected directional characteristics by arranging a probe to receive a radio wave radiated from tow antenna elements on a line in the direction of the bisector of an angle made by each principal radiation directions of two antenna elements. CONSTITUTION:Each one side of two rectangular flat antenna elements 21, 22 is connected to each other, and two elements 21, 22 are combined at the prescribed angle. Besides, nearly on the line of the bisector of the angle made by the principal radiation directions 21A, 22A of each antenna element 21, 22, the probe 23 to receive the radio wave from the antenna elements 21, 22 is arranged. Accordingly, if the relation of the phases of signals fed to two antenna elements 21, 22 respectively is adjusted as monitoring the intensity of the signals received at the probe 23, the expected directional pattern can be surely attained. Thus, the strict adjustment of the length of a feeder line from a signal generating device becomes useless, and the installing work and the maintenance work can be facilitated.申请人：SUMITOMO ELECTRIC IND LTD更多信息请下载全文后查看。

IEEE 和天线有关名词的定义Antenna: "That part of a transmitting or receiving system which is designed to radiate or to receive electromagnetic waves". An antenna can also be viewed as a transitional structure (transducer) between free-space and a transmission line (such as a coaxial line). An important property of an antenna is the ability to focus and shape the radiated power in space e.g.: it enhances the power in some wanted directions and suppresses the power in other directions.Frequency bandwidth:"The range of frequencies within which the performance of the antenna, with respect to some characteristics, conforms to a specified standard". VSWR of an antenna is the main bandwidth limiting factor.Input impedance: " The impedance presented by an antenna at its terminals". The input impedance is a complex function of frequency with real and imaginary parts. The input impedance is graphically displayed using a Smith chart. Reflection coefficient: The ratio of the voltages corresponding to the reflected and incident waves at the antenna's input terminal (normalized to some impedance Z0). The return loss is related to the input impedance Zin and the characteristic impedance Z0 of the connecting feed line by: Gin = (Zin - Z0) / (Zin+Z0).Voltage standing wave ratio (VSWR): The ratio of the maximum/minimum values of standing wave pattern along a transmission line to which a load is connected. VSWR value ranges from 1 (matched load) to infinity for a short or an open load. For most base station antennas the maximum acceptable value of VSWR is 1.5. VSWR is related to the reflection coefficient Gin by: VSWR= (1+|Gin|)/(1-| Gin |).Isolation: "A measure of power transfer from one antenna to another". This is also the ratio of the power input to one antenna to the power received by the other antenna, expressed in decibel (dB). The same definition is applicable to two-port antennas such as dual-polarization antennas.Far-field region: "That region of the field of an antenna where the angular field distribution is essentially independent of the distance from a specified point in the antenna region". The radiation pattern is measured in the far field. Antenna polarization: "In a specified direction from an antenna and at a point in its far field, is the polarization of the (locally) plane wave which is used to represent the radiated wave at that point". "At any point in the far-field of an antenna the radiated wave can be represented by a plane wave whose electric field strength is the same as that of the wave and whose direction ofpropagation is in the radial direction from the antenna. As the radial distance approaches infinity, the radius of curvature of the radiated wave's phase front also approaches infinity and thus in any specified direction the wave appears locally a plane wave". In practice, polarization of the radiated energy varies with the direction from the center of the antenna so that different parts of the pattern and different side lobes sometimes have different polarization. The polarization of a radiated wave can be linear or elliptical (with circular being a special case).Co-polarization: "That polarization which the antenna is intended to radiate".Cross-polarization: "In a specified plane containing the reference polarization ellipse, the polarization orthogonal to a specified reference polarization". The reference polarization is usually the co-polarization.Antenna pattern: The antenna pattern is a graphical representation in three dimensions of the radiation of the antenna as a function of angular direction. Antenna radiation performance is usually measured and recorded in two orthogonal principal planes (such as E-Plane and H-plane or vertical and horizontal planes). The pattern is usually plotted either in polar or rectangular coordinates. The pattern of most base station antennas contains a main lobe and several minor lobes, termed side lobes. A side lobe occurring in space in the direction opposite to the main lobe is called back lobe.Normalized pattern: Normalizing the power/field with respect to its maximum value yields a normalized power/field pattern with a maximum value of unity (or 0 dB).Gain pattern: Normalizing the power/field to that of a reference antenna yields a gain pattern. When the reference is an isotropic antenna, the gain is expressed in dBi. When the reference is a half-wave dipole in free space, the gain is expressed in dBd.Radiation efficiency: "The ratio of the total power radiated by an antenna to the net power accepted by the antenna from the connected transmitter".E-plane:"For a linearly polarized antenna, the plane containing the electric field vector and the direction of maximum radiation". For base station antenna, the E-plane usually coincides with the vertical plane.H-plane: "For a linearly polarized antenna, the plane containing the magnetic field vector and the direction of maximum radiation". For base station antenna, the H-plane usually coincides with the horizontal plane.Front-to-back ratio: "The ratio of the maximum directivity of an antenna to itsdirectivity in a specified rearward direction". Sometimes the directivity in the rearward direction is taken as the average over an angular region.Major/main lobe: "The radiation lobe containing the direction of maximum radiation". For most practical antenna there is only one main beam.Side lobe level: Is the ratio, in decibels (dB), of the amplitude at the peak of the main lobe to the amplitude at the peak of a side lobe.Half-power beamwidth: " In a radiation pattern cut containing the direction of the maximum of a lobe, the angle between the two directions in which the radiation intensity is one-half the maximum value". The Half-power beamwidth is also commonly referred to as the 3-dB beamwidth.Antenna directivity: The directivity of an antenna is given by the ratio of the maximum radiation intensity (power per unit solid angle) to the average radiation intensity (averaged over a sphere). The directivity of any source, other than isotropic, is always greater than unity.Antenna gain:The maximum gain of an antenna is simply defined as the product of the directivity by efficiency. If the efficiency is not 100 percent, the gain is less than the directivity. When the reference is a loss less isotropic antenna, the gain is expressed in dBi. When the reference is a half wave dipole antenna, the gain is expressed in dBd (1 dBd = 2.15 dBi ).Antenna efficiency: The total antenna efficiency accounts for the following losses: (1) reflection because of mismatch between the feeding transmission line and the antenna and (2) the conductor and dielectric losses.Effective radiated power (ERP): "In a given direction, the relative gain of a transmitting antenna with respect to the maximum directivity of a half-wave dipole multiplied by the net power accepted by the antenna from the connected transmitter".Power handling: Is the ability of an antenna to handle high power without failure. High power in antenna can cause voltage breakdown and excessive heat (due to conductor and dielectric antenna losses) which would results in an antenna failure.Passive intermodulation (PIM):As in active devices, passive intermodulation occurs when signals at two or more frequencies mix with each other in a non-linear manner to produce spurious signals. PIM is caused by a multitude of factors present in the RF signal path. These include poor mechanical contact, presence of ferrous contents in connectors and metals, andcontact between two galvanically unmatched metals. PIM spurious signal, which falls in the up link band, can degrade call quality and reduce the capacity of a wireless system.Side lobe suppression: "Any process, action or adjustment to reduce the level of the side lobes or to reduce the degradation of the intended antenna system performance resulting from the presence of side lobes". For base station antenna, the first side lobe above the horizon is preferred to be low in order to reduce interference to adjacent cell sites. At the other hand, the side lobes below the horizon are preferred to be high for better coverage.Null filling: Is the process to fill the null in the antenna radiation pattern to avoid blind spots in a cell site coverage.Isotropic radiator: "A hypothetical, loss less antenna having equal radiation intensity in all direction". For based station antenna, the gain in dBi is referenced to that of an isotropic antenna (which is 0 dB).Omnidirectional antenna: "An antenna having an essentially non-directional pattern in a given plane of the antenna and a directional pattern in any orthogonal plane". For base station antennas, the omnidirectional plane is the horizontal plane.Directional antenna:"An antenna having the property of radiating or receiving electromagnetic waves more effectively in some directions than others".Half-wave dipole:"A wire antenna consisting of two straight collinear conductors of equal length, separated by a small feeding gap, with each conductor approximately a quarter-wave length long".Log-periodic antenna: "Any one of a class of antennas having a structural geometry such that its impedance and radiation characteristics repeat periodically as the logarithm of frequency".Microstrip antenna: "An antenna which consists of a thin metallic conductor bonded to a thin grounded dielectric substrate". An example of such antennas is the microstrip patch.Linear array: A set of radiating elements (e.g. dipole or patch) arranged along a line. Radiating elements such as dipole and patch have dimensions comparable to a wavelength. A linear array has a higher gain, than a single radiator, and its radiation pattern can be synthesized to meet various antenna performance requirements such as upper side lobe suppression and null fill. Itshould be noted that the gain of any antenna is proportional to its size.Coaxial antenna: "An antenna comprised of a extension to the inner conductor of a coaxial line and a radiating sleeve which in effect is formed by folding back the outer conductor of the coaxial line".Collinear array antenna: "A linear array of radiating elements, usually dipoles, with their axes lying in a straight line".Adaptive (smart) antenna:"An antenna system having circuit elements associated with its radiating elements such that one or more of the antenna properties are controlled by the received signal".。

专利名称：ANTENNA发明人：USUI TAKESHI,KOBAYASHI ATSUSHI 申请号：JP10948791申请日：19910515公开号：JPH04337905A公开日：19921125专利内容由知识产权出版社提供摘要：PURPOSE:To enable assembly and manufacture with a little man-hour and to reduce the number of parts. CONSTITUTION:An antenna element formed by a metal plate is fixed to the inner face of a housing 1 in counter to an opening part 2. A dielectric plate 4 is fitted into the housing 1, and a ground 5 formed by a metal plate is fitted and fixed to the opening part 2 of the housing, and the dielectric plate 4 is sandwiched between the ground 5 and the antenna element 3. The antenna can be constituted by respectively integrating the antenna element 3, ground 5, which are formed by the metal plates, and the dielectric plate 4 forming a dielectric layer into the housing 1. By fitting the ground 5 formed by the metal plate into the opening part 2 of the housing 1, it can be also used as the cover of the housing 1.申请人：MATSUSHITA ELECTRIC WORKS LTD更多信息请下载全文后查看。

专利名称：ANTENNA发明人：KATAKI TAKASHI,MANO SEIJI,CHIBA ISAMU 申请号：JP16167282申请日：19820917公开号：JPS5951371A公开日：19840324专利内容由知识产权出版社提供摘要：PURPOSE:To detect the coming direction of radio waves quickly with limited processing circuits by determining the direction of coming radio waves based on the combination of Fourier transform values of signals separately received with the antenna arrays. CONSTITUTION:A plurality of coming radio waves, for example, two are received with linear array antennas 2a-2c and processed with a Fourier transform section of corresponding angle computing units 3a-3c to detect the conic angles of a cone with the array axis of antennas 2a-2c and the direction of coming radio waves. The direction of radio waves is determined with direction detection circuits 4d, 4e depending on the combination thereof. Based on the combination, directions of coming radio waves is calculated through a calculation circuit 5. With such an arrangement, directions of coming radio waves are detected quickly with limited processing circuits.申请人：MITSUBISHI DENKI KK更多信息请下载全文后查看。

专利名称：ANTENNA发明人：WATABE TSUTOMU,UEMICHIHIROYUKI,TAKEYA SHINICHI,SASAKIYOSHITAKA申请号：JP27202988申请日：19881028公开号：JPH02119303A公开日：19900507专利内容由知识产权出版社提供摘要：PURPOSE:To attain the simplification of structure and the easiness of an operation by covering an antenna system with a radome in a part of which polarization converter such as a meandering line polarizer, etc., is arranged, and performing the switching of a polarized wave based on the displacement of the relative position of those radome part and antenna system. CONSTITUTION:Assuming that an antenna 5 is fixed, the radome part 61 in which the meandering line polarizer is arranged is confronted with the pointing direction of the antenna 5 via the horizontal circuit like arrow head F of the radome 6. In the case of setting the relative position of those radome 6 and antenna 5, a linearly polarized wave transmitted from the antenna 5 is converted to a circularly polarized wave, then, is radiated. In the case of setting the relative position of the radome 6 with the antenna 5 so as to confront an ordinary radome part 62 with the pointing direction of the antenna 5, the linearly polarized wave transmitted from the antenna 5 is radiated as it is as the linearly polarized wave. Therefore, it is possible to freely switch the circularly polarized wave and the linearly polarized wave.申请人：TOSHIBA CORP更多信息请下载全文后查看。