The script finally produces an animation of the radiated field. The script allows to set a wanted value of multiple layers, with their own relative electric permittivity, relative magnetic permeability, conductivity (see the LAYERS PARAMETERS section in the script). The function implements a horizontal magnetic dipole (along the x-axis) and calculates the x and z component of the magnetic field for y = 0. Magnetic dipole radiation through a multilayered structure
HIGH RESOLUTION SMITH CHART WINDOWS 7
Platforms: Matlab (R2007a and following versions) Windows XP and Windows 7 (Matlab not needed available upon request: send an email to This email address is being protected from spambots.
HIGH RESOLUTION SMITH CHART ARCHIVE
Take a look at the "Help.html" file included into the zip archive for a comprehensive description of the GUI features. Also double-negative materials are supported. The GUI provides graphical results as well as detailed calculations of the transmission line equivalent circuit model. This tool is a Graphical User Interface (GUI) for the analysis of the TE/TM plane waves propagation through structures composed by multiple layers with different electromagnetic characteristics. The reflection coefficient (\$\Gamma\$ or \$S_ \cdot x = 50 \cdot 1.Graphical User Interface for TE/TM electromagnetic plane waves propagation through multilayered structures To give a very quick explanation of the Smith chart, it rests on one simple idea: You'll understand this once you've read it :-) Smith Chart tutorial from Maxim - reasonable "dense" but looks understandable. Superb Smith Chart resource - essentially an index of indexes - breaks subject up into sections and provides many references for each. Somewhat gentle introduction - 27 page powerpoint intro - still gets deep quite quickly BUT a Smith Chart can be very very useful with almost no maths or numerics involved. However, the remainder is still mathematically relevant, being used, for example, in oscillator design and stability analysis. The Smith chart is most frequently used at or within the unity radius region. The Smith chart can be used to represent many parameters including impedances, admittances, reflection coefficients, scattering parameters, noise figure circles, constant gain contours and regions for unconditional stability, including mechanical vibrations analysis. Use of the Smith chart utility has grown steadily over the years and it is still widely used today, not only as a problem solving aid, but as a graphical demonstrator of how many RF parameters behave at one or more frequencies, an alternative to using tabular information. Smith (1905–1987), 1 is a graphical aid or nomogram designed for electrical and electronics engineers specializing in radio frequency (RF) engineering to assist in solving problems with transmission lines and matching circuits. The Smith chart, invented by Phillip H.Wikipedia gives a better than average concise summary: So - see attenuator articles below and then Smith chart articles.Ĭarbon resistors may be carbon film or carbon composition?Ĭarbon film are not suitable for UHF work as they are formed by cutting a spiral track in a carbon film cylinder, so have very substantial inductance.Ĭarbon composition have a solid carbon body and may be suitable for UHF work depending on other factors. but doesn't that just help attenuation? Thanks again.Ī Smith Chart is not so much an attenuator design aidĪs a means of evaluating and adjusting a design. If I'm just trying to reduce signal power at the output, does it matter where/how the loss happens? So I know poor impedance matching as indicated by my charts means a higher VSWR. Here are the log plots of attenuation over the frequency range I am interested in:Īlso, another question struck me. This is the SC of my cable WITH the attenuator in the middle of it This is the SC of my taken apart coaxial cable WITHOUT the attenuator My questions are as follows: What is a Smith chart and how do I use it to improve my attenuator+cable design? Is this a feasible method for creating basic fixed RF attenuators given that they don't need to be super accurate and only need to function over a very specific range of frequencies (905-920 ish MHz)? Basically I took apart a coaxial cable and hand soldered in some close-to-calculated carbon 5% resistors in between the two SMA connector ends. Now I should mention that my prototype is very shotty. However, the smith chart is all over the place when I measure S11. I have prototyped one using just off the shelf resistors in a T-pad configuration that gives me a decent level of attenuation (pretty flat 19dB) when I perform an S21 measurement using my network analyzer. I need a few different levels of attenuation but each different attenuator can be fixed. I'm working on designing some hopefully simple RF (912 MHz) attenuators.
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