【正文】 相對(duì)于總時(shí)間間隔的 百分率。Envelope amplitude distribution (EAD): A cumulative distribution of the impulseresponse positive crossing rates of a bandpass filter at different spectrum amplitudes. 包絡(luò)幅值分布（EAD）：帶通濾波器在頻譜幅值不同時(shí)的脈沖響應(yīng)正交擾率的 累積分布。Noise amplitude distribution (NAD): A distribution showing the pulse amplitude thatis equaled or exceeded as a function of pulse repetition rate. 噪聲幅值分布（NAD）：隨脈沖重復(fù)率變化的一種表征達(dá)到或超過(guò)脈沖幅值的分布函數(shù)。Average crossing rate: The average rate at which a specified level (zero if not specified) is crossed in the positivegoing direction. 平均交擾率：規(guī)定的電平（若不規(guī)定則為0）被正向被交擾的平均比率。Power density: Emitted power per unit crosssectional area normal to the directionof propagation. 功率密度：垂直于傳播方向的每單位橫截面積上輻射通過(guò)的功率。FREQUENCY SPECTRUM MANAGEMENT 頻譜管理Radio waves or Hertzian waves: Electromagnetic waves of frequencies arbitrarily lower than 3000 GHz, propagated in space without artificial guide. 無(wú)線電波或赫茲波：無(wú)人工導(dǎo)引情況下在空間傳播的任何頻率低于3 000 GHz的電磁波。Radiation: The outward flow of energy from any source in the form of radio waves. 輻射：從源發(fā)出的能量以無(wú)線電波的形式向外傳播。 Emission: Radiation produced, or the production of radiation, by a radio transmitting station. (For example, the energy radiated by the local oscillator or a radio receiver would not be an emission but a radiation.) Note: However, in the field of EMI/ EMC, the term emission is used to describe the electromagnetic interference (both radiated and conducted) generated by an apparatus or an appliance. 發(fā)射：由無(wú)線電發(fā)射電臺(tái)產(chǎn)生的輻射或輻射產(chǎn)物。[例如，由本地振蕩器或無(wú)線電接收機(jī)產(chǎn)生的能量輻射不是發(fā)射，而是輻射。]注意：然而在EMI/EMC領(lǐng)域，術(shù)語(yǔ)發(fā)射用來(lái)描述由儀器或設(shè)備產(chǎn)生的電磁干擾（含輻射的與傳導(dǎo)的兩種）。Outofband emission: Emission on a frequency or frequencies immediately outside the necessary bandwidth which results from the modulation process, but excluding spurious emissions. 帶外發(fā)射：緊挨在必需的由調(diào)制過(guò)程造成的帶寬之外的一個(gè)或多個(gè)頻率的輻射，但不包括雜散輻射。Spurious emission: Emission on a frequency or frequencies which are outside the necessary bandwidth, the level of which may be reduced without affecting the corresponding transmission of information. Spurious emissions include harmonic emissions, parasitic emissions, intermodulation products, and frequencyconversion products, but exclude outofband emissions. 雜散發(fā)射：必要帶寬外的單個(gè)或多個(gè)頻率點(diǎn)上的發(fā)射。可以減小其電平而不影響相應(yīng)的信息傳輸。雜散輻射包括諧波發(fā)射、寄生發(fā)射、交調(diào)產(chǎn)物及變頻產(chǎn)物。帶外發(fā)射除外。Unwanted emissions: Consist of spurious emissions and outofband emissions. 無(wú)用發(fā)射：包括雜散發(fā)射和帶外發(fā)射。Allocation (of a frequency band): Entry in the Table of Frequency Allocations of a given frequency band for the purpose of its use by one or more terrestrial or space radio munication services or by the radio astronomy service under specified conditions. This term shall also be applied to the frequency band concerned. （頻帶）分配：為了在規(guī)定條件下實(shí)現(xiàn)地球或太空范圍內(nèi)的一項(xiàng)或多項(xiàng)無(wú)線通信或射電天文學(xué)服務(wù)，將一給定的頻帶登記到頻率分配表中。Allotment (of a radio frequency or radio frequency channel): Entry of a designated frequency channel in an agreed plan, adopted by a petent conference, for use by one or more administrations for a terrestrial or space radio munication service in one or more identified countries or geographic areas and under specified conditions. （無(wú)線電頻率或無(wú)線電頻率信道的）分配：供一個(gè)或多個(gè)管理機(jī)關(guān)按規(guī)定條件用于一個(gè)或多個(gè)參與國(guó)或地區(qū)進(jìn)行地球或太空范圍內(nèi)的無(wú)線通信服務(wù)，被授權(quán)會(huì)議接受登記一個(gè)約定計(jì)劃中指定的頻率信道。Assignment (of a radio frequency or radio frequency channel): Authorization given by an administration for a radio station to use a radio frequency or radio frequency channel under specified conditions. （無(wú)線電頻率或無(wú)線電頻率信道的）分配：由無(wú)線電臺(tái)站管理部門核準(zhǔn)，按規(guī)定條件使用無(wú)線電頻率或無(wú)線電頻率信道。Assigned frequency band: The frequency band within which the emission of a station is authorized。 the width of the band equals the necessary bandwidth plus twice the absolute value of the frequency tolerance. Where space stations are concerned, the assigned frequency band includes twice the maximum Doppler shift that may occur in relation to any point of the earth39。s surface. 分配的頻帶：臺(tái)站在批準(zhǔn)的頻帶內(nèi)發(fā)射；該頻帶的寬度等于必要帶寬加上頻率容限絕對(duì)值的2倍。對(duì)于空間站，指定的頻帶包括可以發(fā)生在有關(guān)的地球表面上任何地點(diǎn)的最大多卜勒頻移的2倍。Assigned frequency: The center of the frequency band assigned to a station. 分配的頻率：分配給臺(tái)站的頻帶的中心頻率。Frequency tolerance: The maximum permissible departure by the center frequency of the frequency band occupied by an emission from the assigned frequency, or by the characteristic frequency of an emission from the reference frequency. The frequency tolerance is expressed in parts in million per Hertz. 頻率容限：發(fā)射占有的帶寬中心頻率相對(duì)于指定頻率的，或發(fā)射的特征頻率相對(duì)于參考頻率的最大允許偏差。頻率容限以每赫茲百萬(wàn)分之幾來(lái)表示。Interference: The effect of unwanted energy caused by one or a bination of emissions, radiations, or inductions upon reception in a radio munication system, manifested by any performance degradation, misinterpretation, or loss of information which could be extracted in the absence of such unwanted energy. 干擾：在無(wú)線電通信系統(tǒng)接收時(shí)，由一種發(fā)射、輻射、感應(yīng)或它們的組合產(chǎn)生的無(wú)用能量的效應(yīng)，表現(xiàn)為性能下降、誤判或使得原本沒(méi)有這種無(wú)用能量時(shí)能提取到的信息丟失。Protection ratio: The minimum value of the wantedtounwanted signal ratio, usually expressed in decibels, at the receiver, input determined under specified conditions such that a specified reception quality of the wanted signal is achieved at the receiver output. 防護(hù)率：在規(guī)定條件下，例如接收機(jī)輸出的有用信號(hào)達(dá)到規(guī)定的接收質(zhì)量，所確定的接收機(jī)輸入的有用信號(hào)與無(wú)用信號(hào)之比的最小值，通常以分貝表示。SIGNAL INTEGRITY 信號(hào)完整性Fall time: Time for a signal to change from a logic high state to a logic low state. 下降時(shí)間：信號(hào)從邏輯高狀態(tài)變化到邏輯低狀態(tài)所經(jīng)歷的時(shí)間。Flight time: Time difference between the signal at the driver reaching Vref with a reference/test load and the signal at the receiver reaching Vref. Flight time is also known as bus loss, since it historically was used to derate the spec Tco timing to account for the difference between the spec load and the actual system load impact on circuit timing. 飛行時(shí)間：在激勵(lì)器接參考/試驗(yàn)負(fù)載情況下信號(hào)達(dá)到Vref與接收機(jī)信號(hào)達(dá)到Vref之間的時(shí)間差。飛行時(shí)間又稱總線損耗，因?yàn)闅v史上曾用于減小額外時(shí)間Tco，觀測(cè)Tco是為了考慮專用負(fù)載與實(shí)際系統(tǒng)負(fù)載在影響環(huán)路時(shí)間方面的差別。ISI (Inter Symbol Interference): ISI refers to the interactions between the logic value/ symbol from the previous switching cycle and the symbol traveling on the same channel of the current cycle. ISI occurs as a result of energy stored in the channel summing with a latter unrelated signal. It is de