【正文】 a matched balanced lossless tuned dipole radiator to that at the output of a similarly balanced matched lossless tuned dipole receiving antenna for specified polarization, separation, and heights above a flat reflecting surface. 場地衰減：對于規(guī)定的極化、收發(fā)天線間距及距反射平面高度，輸入匹配平衡無耗調(diào)諧偶極子輻射器的功率與同樣是匹配平衡無耗調(diào)諧的偶極子接收天線輸出功率之比值。Singlesignal method: A method of measurement in which the response of the receiver to an unwanted signal is measured in the absence of the wanted signal. 單信號法：在沒有有用信號的情況下測量接收機對無用信號響應的方法。Bandwidth (of a device): The width of the frequency band over which a given characteristic of an equipment or transmission .channel does not differ from its reference value by more than a specified amount or ratio. (The given characteristic may be, for example, that of amplitude/frequency, phase/frequency, or delay/frequency.) （設備的）帶寬：設備或傳輸信道的給定特性偏離其參考值不超過某一規(guī)定值 或比率時的頻帶寬度。 in such cases a different percentage may be useful. 占用帶寬：低于頻率下限與高于頻率上限的帶寬上發(fā)射的平均功率各等于一給%。Emission: An act of throwing out or giving off, generally used here in reference to electromagnetic energy. 發(fā)射：這里通常是指發(fā)出或放出電磁能量的一種作用。雜散 發(fā)射除外。Effective selectivity: selectivity under specified special conditions such as when input receiver circuits are overloaded. 有效選擇性：在規(guī)定的特殊條件下，例如接收機輸入電路過載時的選擇性。Intermodulation: A process occurring in a nonlinear device or transmission mediumwhereby the spectral ponents of the input signal or signals interact to producenew ponents having frequencies equal39。Signaltodisturbance ratio: The ratio of the wanted signal level to the electromagnetic disturbance levels as measured under specified conditions. 信騷比：規(guī)定條件下測得的有用信號電平與電磁騷擾電平之間的比值。Probability density function: The derivative of the distribution function P(x). 概率密度函數(shù)：分布函數(shù)P（x）的導數(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。 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：由無線電發(fā)射電臺產(chǎn)生的輻射或輻射產(chǎn)物。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：必要帶寬外的單個或多個頻率點上的發(fā)射。Unwanted emissions: Consist of spurious emissions and outofband emissions. 無用發(fā)射：包括雜散發(fā)射和帶外發(fā)射。Assigned frequency band: The frequency band within which the emission of a station is authorized。Assigned frequency: The center of the frequency band assigned to a station. 分配的頻率：分配給臺站的頻帶的中心頻率。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. 防護率：在規(guī)定條件下，例如接收機輸出的有用信號達到規(guī)定的接收質(zhì)量，所確定的接收機輸入的有用信號與無用信號之比的最小值，通常以分貝表示。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。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. 飛行時間：在激勵器接參考/試驗負載情況下信號達到Vref與接收機信號達到Vref之間的時間差。頻率容限以每赫茲百萬分之幾來表示。s surface. 分配的頻帶：臺站在批準的頻帶內(nèi)發(fā)射；該頻帶的寬度等于必要帶寬加上頻率容限絕對值的2倍。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. （無線電頻率或無線電頻率信道的）分配：供一個或多個管理機關(guān)按規(guī)定條件用于一個或多個參與國或地區(qū)進行地球或太空范圍內(nèi)的無線通信服務，被授權(quán)會議接受登記一個約定計劃中指定的頻率信道。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。]注意：然而在EMI/EMC領(lǐng)域，術(shù)語發(fā)射用來描述由儀器或設備產(chǎn)生的電磁干擾（含輻射的與傳導的兩種）。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. 無線電波或赫茲波：無人工導引情況下在空間傳播的任何頻率低于3 000 GHz的電磁波。Envelope amplitude distribution (EAD): A cumulative distribution of the impulseresponse positive crossing rates of a bandpass filter at different spectrum amplitudes. 包絡幅值分布（EAD）：帶通濾波器在頻譜幅值不同時的脈沖響應正交擾率的 累積分布。Protection ratio: The minimum value of the signaltodisturbance ratio required toachieve a specified performance of a device or equipment. 保護率：裝置或設備達到規(guī)定性能所需的最小信騷比。Image rejection ratio: The ratio of the level of a specified signal at the image frequency to the level of a signal at the tuned frequency producing the same output power. 鏡像抑制比：接收機鏡像頻率上的規(guī)定信號電平與產(chǎn)生同樣輸出功率的調(diào)諧頻率的（有用）信號電平之比。Desensitization: A reduction of the wanted output of the receiver because of anunwanted signal. 靈敏度降低：由于無用信號引起的接收機有用輸出的減小?？梢詼p小 其電平而不影響相應的信息傳輸。Narrowband emission: An emission that has a bandwidth less than that of a particular measuring apparatus or receiver. 窄帶發(fā)射：帶寬小于特定測量設備或接收機帶寬的發(fā)射。Broadband device: A device whose bandwidth is such that it is able to accept and process all the spectral ponents of a particular emission. 寬帶設備：帶寬足以接收和處理特定發(fā)射的所有頻譜分量的設備。）Bandwidt