![]() The demoversion may be freely distributed. The dashed-line circle in each plot is the demarcation circle of return loss as mentioned in Chapter 3, where S 11 or S 22 = − 10 dB. Smith-Chart Software and Related Documents Version Smith V4.1 Without license the application will work in demo mode only. (The methodology of impedance matching in the wideband case introduced and discussed in this chapter was developed in 2005 by the author specially for a UWB (ultra wideband) system and has not been made public until now).įigure 4.1 shows the difference of the return loss or impedance on the Smith Chart between the narrow and wideband cases. In this chapter, we will apply the same process of impedance matching as in the narrowband case, but the main effort will to expand the skill from narrow to wide bandwidth. In the wideband case, instead of a single frequency, the entire wide bandwidth must be taken care of, which makes impedance matching somewhat difficult. Smith Chart provides a visual tool for designing and analyzing amplifiers, matching networks and transmission lines. The Smith Chart - Impedance Matching with Tx Lines, Series Inductors and Capacitors Smith Chart Tutorial - Impedance Matching with Tx Lines, Series L and C On the previous page, we showed how to use series inductors and capacitors to cancel out the reactance of a load. However, in the narrowband case, only one frequency needs to be taken care of in the process of impedance matching because a narrow bandwidth can be represented approximately by the central frequency. The methodology of impedance matching is basically the same between narrow and wideband cases. Figure 18 shows how inductors and capacitors can be used to change the impedance.Impedance Matching in the Wideband Case 4.1 Appearance of Narrow and Wideband Return Loss on a Smith Chart Capacitors and inductors in series or parallel can be used to match the antenna to the desired impedance. In this article, from the perspective of impedance matching, structure principle and characteristics of Smith chart are introduced. If varying these factors is not possible or if the performance still needs to be improved, discreet components could be used to optimize the impedance. Thus by varying these factors it might be possible to improve the impedance match of the antenna. Size of ground plane, distance from antenna to ground plane, dimensions of antenna elements, feed point, and plastic casing are factors that can affect the impedance. Analyzing an actual antenna response on the Smith Chart (froma network analyzer) is also performed. The following figure shows an overview of the possible matching circuits and changes in the Smith Chart. Dependent of the antenna type there are several possibilities to obtain optimum impedance at the correct frequency. The Smith Chart - Dual Band Impedance Matching Dual-Band Impedance Matching Dual-band impedance matching is introduced on this page via an example. ![]() If the resonance frequency is too high, the antenna length should be increased.Įven if the antenna resonates at the correct frequency it might not be well matched to the correct impedance. For a matching network that contains elements connected in series and parallel, we will need two types of Smith charts. Thus if the resonance frequency is to low, the antenna should be made shorter. The interactive Smith chart enables users to navigate their way around a Smith chart, using simple discrete element impedance matching. Ideally the frequency which gives least reflection should be in the middle of the frequency band of interest. For resonant antennas the main factor is the length. There are several ways to tune an antenna to achieve better performance. ![]() This tool calculates the matching network necessary to terminate a line of the specified characteristic impedence. Web in this video, i have explained smith chart example with following outlines.0. especially built-in antennas, such as spring type, chip type, pcb or fpc type antenna. Use this handy smith chart web app to create matching networks. To be precise, all antennas need impedance matching when applied to products. click anwhere inside the chart to see the corresponding circles 3. Antenna Matching is very important work in client side, not only antenna supplier side.
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