insertion loss
оптические вносимые потери
вносимые потери
Отношение суммарной мощности оптического излучения на входных оптических полюсах компонента ВОСП к суммарной мощности оптического излучения на выходных полюсах компонента ВОСП, выраженное в децибелах.
[ГОСТ 26599-85]
Термин «вносимые потери» (insertion loss) заменил термин «затухание» (attenuation) при измерении потерь сигнала, снимаемых как с линий, так и с каналов. Причина изменения в том, что коммутирующее оборудование и процесс инсталляции изменяют динамику процессов передачи кабеля. Следовательно, у кабеля, приобретенного у производителя, будет измеряться затухание (attenuation). Как только кабель был инсталлирован и оконцован коннекторами, во всех дальнейших тестированиях будут измеряться «вносимые потери» (insertion loss) в линии или канале.
Тематики
Синонимы
остаточное затуание
—
[Л.Г.Суменко. Англо-русский словарь по информационным технологиям. М.: ГП ЦНИИС, 2003.]
Тематики
потери в СВЧ разряде резонансного разрядника
потери в разряде
αразр
Потери, вызываемые рассеиванием СВЧ мощности в СВЧ разряде резонансного разрядника.
[ГОСТ 23769-79]
Тематики
Обобщающие термины
Синонимы
Тематики
1.5.15 вносимое затухание (insertion loss): Отношение напряжения, измеренного на выводах до включения помехоподавляющего устройства, к напряжению после его включения.
3.21 потери при включении (insertion loss): Потери при включении УЗИП, определяющиеся отношением напряжений на выводах, измеренных сразу же после подключения испытуемого УЗИП к системе, до и после включения. Результат выражается в процентах.
3.9 вносимые потери (insertion loss) Di, дБ: Разность уровней звуковой мощности проходящего по каналу или через отверстие звука при наличии глушителя и в его отсутствие.
3.3 вносимые потери (insertion loss), дБ: Разность уровней звукового давления на приемнике, установленном в контрольной точке, при отсутствии и наличии экрана и при отсутствии других значительных явлений, отрицательно влияющих на распространение звука.
В стандарте применены обозначения, указанные в таблице 1.
Затухание в октавной полосе частот
Поправка на метеорологические условия
Расстояние от точечного источника шума до приемника (рисунок 3)
Проекция расстояния от точечного источника шума до приемника на плоскость земли (рисунок 1)
Расстояние от точечного источника шума до точки отражения на звукоотражающем экране (рисунок 8)
Расстояние от точки отражения на звукоотражающем экране до приемника (рисунок 8)
Расстояние от точечного источника шума до дифракционной кромки (первой) (рисунки 6 и 7)
Расстояние от второй дифракционной кромки до приемника (рисунки 6 и 7)
Показатель направленности точечного источника шума
Затухание на экране
Расстояние между первой и второй дифракционными кромками
Коэффициент отражения от поверхности земли
Средняя высота источника шума и приемника
Высота точечного источника шума над землей (рисунок 1)
Высота приемника над землей (рисунок 1)
Средняя высота траектории распространения звука над землей (рисунок 3)
Максимальный размер источника шума
Минимальный размер (длина или высота) звукоотражающей плоскости (рисунок 8)
Уровень звукового давления
Коэффициент затухания звука в атмосфере
Угол падения звуковой волны
251. Потери в СВЧ разряде резонансного разрядника
Потери, вызываемые рассеиванием СВЧ мощности в СВЧ разряде резонансного разрядника
Полезное
Смотреть что такое «insertion loss» в других словарях:
Insertion loss — In telecommunications, insertion loss is the decrease in transmitted signal power resulting from the insertion of a device in a transmission line or optical fiber. It is usually expressed relative to the signal power delivered to that same part… … Wikipedia
insertion loss — įneštiniai nuostoliai statusas T sritis fizika atitikmenys: angl. insertion loss vok. Einfügungsverluste, m rus. вносимые потери, f pranc. pertes d’insertion, f … Fizikos terminų žodynas
Insertion Loss — Die Einfügedämpfung (engl. Insertion Loss, IL) gibt die Abschwächung eines Signals durch ein Bauteil an, das in einen Signalweg eingefügt wird. Dabei kann es sich beispielsweise um einen Filter oder auch eine Steckverbindung handeln. Die… … Deutsch Wikipedia
Insertion Loss — WikiV The signal strength loss when a piece of equipment is inserted into a line … Audio and video glossary
вносимые потери D (insertion loss), дБ — 3.1 вносимые потери D (insertion loss), дБ: Уменьшение уровня звуковой мощности, распространяющейся по воздуховоду, обусловленное установкой глушителя в систему воздуховодов вместо участка воздуховода. Источник … Словарь-справочник терминов нормативно-технической документации
Loss — may refer to:*A negative difference between retail price and cost of production *An event in which the team or individual in question did not win. *Loss (baseball), a pitching statistic in baseball *Attenuation, a reduction in amplitude and… … Wikipedia
Insertion — may refer to: *Insertion (anatomy), the point of attachment of a tendon or ligament onto the skeleton or other part of the body *Insertion (genetics), the addition of DNA into a genetic sequence *Insertion loss, in electronics *Insertion sort, a… … Wikipedia
Insertion gain — In telecommunication, insertion gain is the gain resulting from the insertion of a device in a transmission line, expressed as the ratio of the signal power delivered to that part of the line following the device to the signal power delivered to… … Wikipedia
Loss of coolant accident — A loss of coolant accident (LOCA) is a mode of failure for a nuclear reactor; if not managed effectively, the results of a LOCA could result in reactor core damage. Each nuclear plant s Emergency Core Cooling System (ECCS) exists specifically to… … Wikipedia
Return loss — In telecommunications, return loss or reflection loss is the loss of signal power resulting from the reflection caused at a discontinuity in a transmission line or optical fiber. This discontinuity can be a mismatch with the terminating load or… … Wikipedia
Mismatch loss — in transmission line theory is the amount of power expressed in decibels that will not be available on the output due to impedance mismatches and reflections. A transmission line that is properly terminated, that is, terminated with the same… … Wikipedia
What is Insertion loss? What is Return loss?
Insertion loss and return loss are widely used terms in the field of microwave technologies. Insertion loss and return loss plays an important role in designing and development of high-frequency devices such as filters, power dividers, amplifier, etc.
These are quite similar concepts, it is an advanced form of the basic electronics we have learned in network theorems.
What is an insertion loss?
If the power transmitted to the load is PT and the incident power received by the load is PR, then the insertion loss is given by: 
What is a return loss?
Less power reflection is desirable thus high return loss (RL) is considered good according to the formula: 
where RL is the return-loss in dB, Pi is the incident power to the system and Pr is the reflected power from the system.
Figure showing insertion loss offered by a bandpass filter, the required signal at another end will have some power loss:
What causes insertion loss?
Insertion loss causes due to two factors namely ohmic loss, dielectric leakage and the return loss is caused due to mismatched systems.
Miss-matched in the system results in insertion loss and return loss. Ideally reflected power must be equal to zero but, in a practical sense, it has some value that can be up to 10 dB or more even after minimizing these losses.
For maximum power transfer, Xs = Xl
This can be seen as,
When the source impedance is matched with load impedance then ideally return loss must be equal to zero. But practically, it has some value that can be up to 10 dB or more even if the system is matched.
Importance:
Relation with the scattering parameter:
Below image showing insertion loss and return loss for a 90MHz highpass filter matched at 50 Ohms.:
Insertion loss and return loss are linked with the scattering perimeter when the source and the load of the system is matched to the same reference impedance (say 50 Ohms).
S parameters are is the modern way of analyzing two-port networks. It is very helpful in in in optimizing the circuit to its best. It is capable of determining even smaller return loss and insertion loss in the form of s-parameters namely S11, S22, S12, S21:
S12 = transmission coefficient (power gain in dB of the system in a forward direction)
S21 = transmission coefficient (power gain in dB of the system in reverse direction)
S11 = reflection coefficient (related to return loss in dB at port 1)
S22 = reflection coefficient (related to return loss in dB at port 2)
For perfectly matched and ideal n/w:
→ S11 = S22 = 0
-→ S12 = minimum
–→ S21 = depends on the nature of the circuit (≥0)
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Reference to Insertion Loss and Return Loss for Fiber Connectors
Worton
As we know, there are a large number of fiber optic cables used between devices in optical communications, and the optical connectors of fiber cables are required to be reliable for high-performance optical fiber networks. When measuring the attenuation effects of the fiber connectors, insertion loss (IL) and return loss (RL) are two essential parameter measurements.
What Is Insertion Loss and Return Loss for Fiber Connectors?
What Is Insertion Loss?
In telecommunications, insertion loss refers to the loss of signal power, calculated as a ratio in dB (decibel), resulting from inserting a device in a transmission line or optical fiber. It can also be referred to as attenuation, which indicates how much the signal loss is by comparing the input power to the output power. A lower insertion loss value indicates a better insertion loss performance. For example, an insertion loss of 0.3dB is better than 0.5dB.
What Is Return Loss?
When a signal is transmitted through a transmission line, some signal power is always reflected or returned to the source due to discontinuities in the transmission line. The discontinuity can be a mismatch with the terminating load or with a device inserted in the line. Return loss refers to the loss of reflected signal power. Therefore, the higher the return loss is, the lower the amount of reflection will be. That is to say, the fiber connector will have better performance with a higher value of RL.
What Causes Poor Insertion Loss and Return Loss?
Ideally speaking, if the fiber patch cable has no connections, then the minimum loss will be realized—a continuous, straight-through glass fiber from Point A to Point B with no interruptions. However, the fiber optic networks are requiring connectors for modularity. The desired low IL and high RL performance are reduced consequently on account of the following three factors:
End-face Quality and Cleanliness
Evidently, fiber end-face defects like scratches, pits, cracks, and particle contamination will have a direct impact on the performance, contributing to poor insertion/return loss. Any irregularity that impedes light transmission from one fiber to the other will negatively affect IL and RL. 
Figure 1: End-face Cleanliness
Misalignment Between the Two Cores
The main task of the connector is to hold the fibers precisely, ensuring the core of one fiber will align neatly and accurately with the core of the other fiber, so as to make every connector to mate with another connector with precise core alignment and core-to-core contact. Normally speaking, the smaller the ferrule hole diameter, the more precisely the fiber will be centered in the ferrule. If the ferrule hole is not perfectly centered, the fiber it holds will obviously never be perfectly centered. Therefore, the misalignment between two cores often happens when the fibers with the light-carrying cores are not aligned perfectly with each other, resulting in poor IL/RL.
Figure 2: Two Cases of Misalignment Situations
Poor Core-to-core Contact
In order to achieve the desired low IL and high RL, optimized core-to-core contact must be achieved and maintained. Different polishing styles of fiber connectors have varied core-to-core contact performance regarding the connector’s insertion loss and return loss. Usually, the insertion loss of PC, UPC, and APC connectors is less than 0.3dB. However, UPC connectors have the lowest IL due to the smallest air gap while APC connectors have the highest RL due to the beveled fiber end-face. PC vs UPC vs APC Connector will help you to select the proper fiber connect type.
Figure 3: Core-to-core Contact of PC vs UPC vs APC
How to Reduce the Loss of Fiber Connectors?
Adopting the well-tested and high-quality connectors may help the network installers to deliver high-speed connections that perform well over the long term. Here are some tips for you to optimize the value of the insertion/return losses:
Keep all the fiber connectors clean, especially before and after the installation and testing. Using the proper tools to clean the connector ferrules.
Minimize the number of tight bends, coils, splices, and connectors, which may cause light to refract through the fiber cladding. If coil fiber is required, then keep the radius as large as possible.
Utilize factory terminated cabling. These terminations are made under stringent guidelines and typically include a manufacturer warranty.
Make a wise budget decision: your «power loss» budget or your cable inventory budget. Purchasing cheap fiber optic cables with the poor quality may bring larger costs further down the line.
In summary, the assessment of efficiency and performance will be more accurate if we combine the measurement parameters of both insertion loss and return loss. The measurements can judge whether there is an impedance mismatch at the pins of the receiver and transmitter as well as the vias, connectors, and various other discontinuities.
Insertion Loss vs. Return Loss: Signal Transmission and Reflection
The term loss is almost unilaterally associated with a negative in nearly every conceivable scenario. Take, for example, the loss administered to a certain NFL team (New England) by the magnificence of a certain quarterback (Lamar Jackson) from Baltimore. In this case, if you are a fan of TB 12’s team, then this is most definitely a negative. However, if you are not a fan, then this is one of those rare occasions in which a loss is not a negative.
In the field of electronics, the term loss can also hold a dual relative meaning. So, depending on the circumstances, the term loss can be either a good thing or a bad thing. However, as it is in most cases, the term loss tends to lend itself to the side of negative in the field of electronics as well.
All losses are not equal, and a loss can come in many forms, such as a power loss, connectivity loss, insertion loss, and even a return loss. Furthermore, in the field of electronics, losses such as insertion loss are an essential performance parameter measurement in designs consisting of fiber-optic links. So, over the next few paragraphs, I will discuss the significance of both insertion loss and return loss as well as their effects on performance and functionality.
What is Insertion Loss?
The loss of signal, which occurs along the length of a fiber optic link, is called insertion loss. This particular measurement parameter is expressed in decibels and should always be a positive number. However, should, does not mean always, and if by chance, it is negative, that is not a favorable measurement parameter.
Insertion loss is, however, a natural occurrence that occurs with all types of transmissions, whether it is data or electrical. Furthermore, as it is with basically all physical transmission lines or conductive paths, the longer the path, the higher the loss. Moreover, these losses also occur at each connection point along the line, including splices and connectors.
As stated initially, we express insertion loss in dBs (decibels), and ordinarily, it is a positive number since it indicates how much signal loss by comparing the input power to the output power. In summary, a signal will always come out lesser than their input level. Furthermore, the lower the number equals a better insertion loss performance; for example, an insertion loss of 0.3dB is better than 0.5dB.
In some instances, an insertion loss may appear as a negative parameter measurement. However, if this is the case, a negative insertion loss means that there is an issue, one of which usually indicates an improper reference setting. For instance, if a reference cable requires cleaning when setting the zero benchmark, and you clean it prior to testing, the insertion loss may show a gain and possibly indicate a negative measurement parameter.
Balancing signals can be tremendously difficult without the right tools.
What is Return Loss?
The measurement of the amount of light that is reflected back toward the source is called Return loss, and its unit of expression is also in decibels (dBs). Furthermore, this measurement parameter is always a positive number, and a high return loss is a favorable measurement parameter, and it typically correlates to a low insertion loss. Similarly, reflectance, which is also a measurement parameter that expresses reflection in decibels, is a negative number, and if it is excessive, it is not a favorable measurement parameter.
In summary, return loss is the loss of signal power due to signal reflection or return by a discontinuity in a fiber-optic link or transmission line. This impedance mismatch can be with a device inserted in the line or with the terminating load. Moreover, return loss is the relationship between both the reflection coefficient (Γ) and the standing wave ratio (SWR). Incidentally, if you increase the return loss, it will correlate to a lower SWR.
Overall, return loss is a measurement parameter that expresses how well a device or line matches. The rule of thumb here is, it is favorable if the device or line match, providing that the return loss is high. Furthermore, a high return loss is advantageous as it will result in a lower insertion loss.
In today’s electronics practices, in terms of use, return loss is preferable to SWR since it affords better resolution for smaller values of reflected waves.
Insertion Loss vs. Return Loss
As previously stated, regardless of type, when a signal travels through a system or a component, power (signal) loss is unavoidable. This loss I am referring to happens while the signal is traversing through a system or a component; it, of course, is called Insertion Loss.
Furthermore, there a myriad of reasons for this loss of signal power or insertion loss, but the main three are as follows:
Dielectric Losses: Loss can occur due to power dissipation in the dielectric materials.
Reflected Losses: Loss can occur due to the Voltage Standing Wave Ratio (VSWR). VSWR is a measure of the efficiency of the transmission of radio frequency power from its source through a transmission line and into a load, such as from a power amplifier, through a transmission line, and to an antenna.
Copper Losses: Loss can occur due to the power dissipation of conducting surfaces.
So now, let us examine the above diagram in detail so that we may gain a better understanding of how insertion loss and return loss interact. As you can see, incident power travels down a transmission line from the left until it reaches the component. Once it reaches the component, a portion of the signal is reflected back down the transmission line towards the source from which it came. Also, keep in mind that this portion of the signal does not enter the component.
The remainder of the signal does indeed enter the component. There some of it gets absorbed, and the rest passes through the component into the transmission line on the other side. The power that comes out of the component is called the transmitted power, and it is less than the incident power for two reasons:
1. A portion of the signal gets reflected.
2. The component absorbs a portion of the signal.
So, in summary, we express insertion loss in decibels, and it is the ratio of incident power to transmitted power. Furthermore, we can summarize that return loss, which we also express in decibels is the ratio of incident power to reflected power. Therefore, we can see how the two types of loss measurement parameters help to accurately gauge the overall efficiency of a measurable signal and component within a system or in a through path.
Determining insertion loss and return loss in high speed circuits requires understandings of component relationships.
In conclusion, when we combine the measurement parameters of both insertion loss and return loss, we can more accurately assess efficiency and performance. Furthermore, it can determine if there are impedance mismatches at the pins of the receiver and transmitter as well as the vias, connectors, and various other discontinuities. In short, the overview that these two parameter measurements provide is an essential assessment tool in understanding signal performance.
Insertion loss vs return loss parameters can be measured easily within the suite of design and analysis tools from Cadence. If you’re looking for easy layout solutions and comprehensive analysis or simulation options, look no further than Allegro PCB Designer.
If you’re looking to learn more about how Cadence has the solution for you, talk to us and our team of experts
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