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signal strength is presented using a color-coding scheme. This provides a good overview of the signal behaviour and allows assessment of the timing even for brief signal impairments. If impairments of this sort occur, additional functions can be used for further detailed analysis. The RF spectrum diagram, for example, provides a picture of the measured signal’s overall spectrum at a selected time. It shows the spectrum not only of the wanted signal but also of possible impairments. With the “Frequency Deviation Time Domain” diagram, the frequency errors determined in this manner for a complete chirp can then be demodulated and displayed separately. If you are interested in detecting very low-amplitude impairments, you can additionally use video filters or averaging over multiple chirps to minimize any noise that is present. Accuracy of the speed measurement Another important parameter during development of radar sensors is the deviation from the ideal chirp length, since this influences the accuracy of the speed measurement. For this purpose, the measurement results are displayed in a table with the start time and length of the chirp along with the parameters mentioned above. All of the chirps that fall into a previously defined result range are taken into account. Each individual chirp can be identified based on a timestamp. In addition, the chirps are sequentially numbered in a table so they can be better distinguished from one another. The measurements described here can be performed with the spectrum analyzers up to a frequency of 67 GHz without Fig. 4 The R&S FSW displays important chirp parameters such as the chirp rate, chirp length and chirp rate deviation in a result table. any additional accessories. In situations requiring measurement of radar signals at frequencies over 67 GHz, harmonic mixers must be used to convert the input signal to the analyzer’s intermediate frequency (IF). It is important for the analyzer to use the highest possible IF, since this results in a wide and unambiguous frequency range. This is especially critical when analyzing broadband signals such as LFMCW signals. A new vision for wound components The wound components you have been looking for are here and available to meet your precise specifications, in just 4 weeks. With the flexibility to suit your changing volume requirements, however fast they happen. It’s a vision of the future, that’s happening now. Precision brand wound components Manufactured for speed, quality, flexibility and value Samples available in just 14 days For more information please visit our website. 4-week delivery Rapid volume adjustment easily accommodated Visit us at Electronica in Hall B2, Stand 144 www.precision-range.com www.electronics-eetimes.com Electronic Engineering Times Europe October 2014 39


EETE OCT 2014
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