My 40year love affair with a remarkable amplifiera class. Application note an insight intermodulation distortion measurement methods using the ifr 2026ab multisource generator. Pdf theoretical analysis of intermodulation distortion in ofdm. This utility offers an ability to convert the pdf content in four distinctive modes. A comprehensive analysis of analog and digitally modulated waveforms in the transmission lines with weak distributed. Emphasis will be placed on the measurement of third order products and the calculations required to determine the third order intercept point toi or ip3. Passive intermodulation distortion in connectors, cable and cable assemblies reduce or eliminate the pim generated by the active devices in the system david weinstein amphenol corporation communication and network products one kennedy avenue danbury, ct 06810 not all channels. Intermodulation distortion or imd has always existed in rf transmission paths.
The analyzer can measure intermodulation distortion products of order 2, 3, 5, 7, or 9, and can display the associated intercept points. Intermodulation distortion in rf connectors introduction intermodulation distortion or imd has always existed in rf transmission paths. Intermodulation is caused by nonlinear behavior of the collective signal processing physical equipment or even algorithms being used. Reviewing the basics of intermodulation distortion. A method for measuring transient intermodulation distortion tim eero leinonen, matti otala, and john curl technical research centre of finland, electronics laboratory, sf90101 oulu, finland. Passive intermodulation distortion pimd is a weakly nonlinear effect and can become the system limiting factor in communication systems by interfering with intended communication signals 3. The causes of intermodulation distortion in magnetic tape recording are discussed. Download novel measurement of intermodulation distortion imd in. Intermodulation distortion imd application option 087. It is one of the key metrics in categorizing the linearity of active and passive electronic components and devices. The only problem with this form of test is that the distortion measured is the combined distortion of both transmitter and receiver. Home package intermodulation distortion in microwave and wireless circuits pdf.
Passive intermodulation distortion 2 parts part 1, pim effects, electrothermal pim test equipment, microwave circuits antennas part 2, pim effects non electrothermal pim, filter pim behavioral modeling behavioral model measurement equipment simulation and modeling of large systems. Intermodulation distortion in microwave and wireless circuits pdf. Read online novel measurement of intermodulation distortion imd in. New progresses in ic technology extend the application of op amps where some years ago discrete circuits played the major role. Nguyen center for integrated microsystems department of electrical engineering and computer science university of michigan ann arbor, michigan 481092122 abstract the mechanism behind third. Intermodulation distortion in rf connectors white paper. Understanding intermodulation distortion measurements.
Intermodulation distortion products are of special interest in the if and rf area, and a major concern in the design of radio receivers. Intermodulation distortion imd can wreak havoc in modern wirelesscommunications systems. The figure above illustrates the interpretation of the intermodulation distortion measurement using a fixed low frequency tone f 1 and a high frequency tone f 2 which is varied over the audio band voice tone sweep. Chapter 2 deals with nonlinear distortion characterization from a practical point of view. A description of the squaresine intermodulation measuring method is given. Rather than simply examining the harmonic distortion or total harmonic distortion thd produced by a single tone sinewave input, it is often required to look at the distortion products produced by two tones. It is shown that nonsymmetrical input signals can be a source of intermodulation in tape recording. Threetone intermodulation distortion generated by superconducting bandpass filters article pdf available in ieee transactions on applied superconductivity 3. Bridge method for measuring amplitude intermodulation distortion matrix test equipment inc. Understanding intermodulation distortion measurements electronic. Until about the early 1990s, cellular communications had relatively low power carrier levels.
In addition, an im spectrum mode gives a spectrumanalyzerlike display for confirming or troubleshooting measurements. Novel measurement of intermodulation distortion imd in. The second and thirdorder intercept points ip2 and ip3 are figures of merit for these specifications and allow distortion products to be computed for various signal amplitudes. Passive intermodulation distortion in connectors, cable. Technical article my 40year love affair with a remarkable amplifiera class b amplifier for audiophiles may 04, 2018 by dermot herron the blomley amplifier was designed over forty years ago, is an alternative power amplifier design that suffers virtually no distortion, and provides a sound which has the presence often lacking in conventional amplifiers. On passive intermodulation test of analog and digital systems.
Intermodulation distortion is the result of two or more signals interacting in a non linear. Understanding how nonlinear effects are produced in both active and passive components can help reduce the generation of imd and resulting interference in communications systems. Intermodulation im or intermodulation distortion imd is the amplitude modulation of signals containing two or more different frequencies, caused by nonlinearities or time variance in a system. Twotone testing for imd has been used to characterize the non. To understand imd, consider a twoport network, such as an amplifier, with the nonlinear transfer function as shown in fig. Thirdorder intermodulation distortion in capacitivelydriven ccbeam micromechanical resonators reza navid, john r. Meyer, fellow, ieee abstract the nonlinearity behavior of cmos currentswitching mixers is investigated. What is imd intermodulation distortionimd is the amplitude modulation of signals containing two or more different frequencies, caused by nonlinearities in a system.
The intermodulation between frequency components will form additional components at frequencies that are not just at harmonic frequencies integer multiples of either, like harmonic distortion, but. There are two files that you can download one is a twotone signal that you can use for testing, and the other is a demonstration of the intermodulation distortion that you can listen to. Passive intermodulation distortion, part 2 ieee web hosting. While this may be convenient to get a basic idea, there is nothing like actually experimenting with the very simple circuit to convince yourself that the. The intermodulation distortion imd performance of 1 wideband, dccoupled amplifiers is a relatively new area for integrated operational amplifier suppliers. The practical measuring procedure is described, and measurement results of commercial audio power amplifiers and integrated operational amplifiers are presented, in many cases showing appreciable transient intermodulation in units which have excellent and total harmonic distortion and smpte intermodulation distortion.
Intermodulation distortion in passive devices was not necessarily a. Intermodulation distortion in passive devices was not necessarily a problem because the distortion levels were significantly below the noise floor of the broadcast system. Imd adds components to the sound that are not found in the original signal. Rf amplifiers engineering notes, rf amplifiers technical reference material. Distributed passive intermodulation distortion on transmission lines article in ieee transactions on microwave theory and techniques 595. This method utilizes a bridge technique to cancel the test signals, leaving the di8 tortion products of the device under test.
This is in contrast to im2 where the frequency of the intermodulation was at a lower and higher frequency. Intermodulation distortion in microwave and wireless. Pdf format this file type includes high resolution graphics and schematics when applicable. Bridge method for measuring amplitude intermodulation. With this program you are able to transfer the entire content of a pdf document or just a selection, to one or multiple spreadsheets.
If your open pdf has more than a single page, select a thumbnail in the lefthand side where you want to insert another pdf file. Intermodulation distortion imd measures the level of unwanted combinations of different frequencies found in the input signal. This application is a solution for converting pdf files to excel format. Measurement of intermodulation distortion at audio frequencies. Intermodulation distortion is a critical symptom of motor nonlinearities represented by a nonlinear.
Passive intermodulation distortion 2 parts part 1, pim effects, electrothermal pim test equipment, microwave circuits antennas part 2, pim effects non electrothermal pim, filter pim behavioral modeling behavioral model measurement equipment. Intermodulation distortion in currentcommutating cmos mixers manolis t. Multitone intermodulation distortion performance of 3rd. Pdf threetone intermodulation distortion generated by. A close correlation exists between harmonic distortion and intermodulation distortion measurements when the individual orders of distortion are measured separately.
This article describes distortion measurement method that greatly ces contributions from the s source and the spectrum analyzer. Passive intermodulation distortion in connectors, cable and cable. It is fairly simple to measure the amount of intermodulation distortion produced by loudspeakers, but it is more difficult to find out how much of this kind of distortion is found objectionable or just detectable when masked by music. This effect results from nonlinearities in your audio system. Intermodulation distortion in currentcommutating cmos. While the stiffness nonlinearity can not produce significant intermodulation, the other nonlinearities generate wideband distortion which can not be detected by a harmonic.
Intermodulation interference is the undesired combining of several signals in a nonlinear device, producing new, unwanted frequencies, which can cause interference in adjacent receivers located at repeater sites. Introduction intermodulation distortion imd is a common problem in a variety of areas of electronics. Imd measurements using dual source and multiple source. We are taking all precautions and following all guidelines as. If excessive distortion occurred, one would have to be certain that it wasnt caused by the receiver. Introduction the theories and operations of intermodulation distortion imd are well understood.
Intermodulation distortion imd is an important consideration in microwave and rf component design. All books are in clear copy here, and all files are secure so dont worry about it. Studies and experience have shown that the harmonic distortion method. The only way to reduce pim in the transmission path is. Interaction of intermodulation products between dut and.
Intermodulation distortion is one of the most interesting signal analyzer measurements. Interfering signals wanted distortion product now we see that even if the system is narrowband, the output of an ampli. Chapter 1 starts by addressing the intermodulation distortion problem, in the most general terms, and from a systems perspective. The better it is understood, the better its effects can be minimized. It is made more difficult by the fact that this has to be done in the absence of other kinds of distortion such as harmonic and transient intermodulation. Intermodulation distortion imd is a popular measure of the linearity of amplifiers, gain blocks, mixers, and other rf components. Theoretical analysis of intermodulation distortion in ofdm signals in the presence of nonlinear rf high power amplifiers.
430 721 644 918 85 582 425 617 994 475 164 465 930 789 532 1101 499 715 944 333 195 1218 853 1159 1173 588 1455 447 14