
NAMEoutput  output data file formatsDESCRIPTIONThis manual page describes the output formats of the files created by the YagiUda project's output program. The files are ASCII file, so can be analysed with any graph plotting program.Example of a .dat FileBelow is a typical .dat file, for a 4ele 144146MHz beam, optimised for a huge (and useless) FB.
What is what in the .dat fileThe f(MHz) column is the frequency (MHz) at which the data is evaluated at.The E(deg) column is the approximate 3dB Eplane bandwidth calculated to the nearest 0.1 degree. The H(deg) column is the approximate 3dB Hplane bandwidth calculated to the nearest 0.1 degree. The (R) column is the input resistance in Ohms. The (jX) column is the input reactance in Ohms. The (VSWR) column is the input VSWR, usually refered to a 50 Ohm input, but this may be changed. The Gain (dBi) column is the gain at theta=90 degrees, which is the forward direction of the beam. It is possible that a higher gain occurs at other than 90 degrees, but this is not taken into account. The antenna is seriously at fault if this occurs. The FB(dB) column is the front to back ratio in dB. The Sidelobes(dB) column is the minimum level in dB down from the peak gain of any sidelobe. This is not calculated unless the 'c' option is used, and then only on some optimisation techniques. Example of a .gai FileThe following is a small section of the .gai file.f(MHz) theta gainE(dBi) G(E)peak phi gainH(dBi) G(H)peak 144.0000 90.0000 12.5584 21.9444 180.0000 12.5584 21.9444 What is what in the .gai fileThe f(MHz) column is the frequency in MHz.The theta column is the angle theta, for which the next two columns refer. The gainE(dBi) is the gain at theta, relative to an isotropic radiator. This is the Eplane gain. Hence at the peak (theta), this gives the peak forward gain. The G(E)peak is the gain at theta, relative to the peak gain. Hence at the peak (theta=90 degrees), this is zero. The phi column has nothing to do with the previous 3 columns. It is the angle for which the next two columns refer. The gainH(dBi) is the gain at phi, relative to an isotropic radiator. This is the Hplane gain. Hence at the peak (phi=0), this gives the peak forward gain. The G(H)peak is the gain at phi, relative to the peak gain. Hence at the peak (phi=0 degrees), this is zero. Example of a .up FileThe .up file list the improvements made by optimise to an antenna design. Starting from the original design, the file is appended each time a new better design is found. Here is an example, where the final line is the performance of the 4ele beam with the .dat file shown earlier.1 7.57dBi, 16.93dB F/B, Z=(31.7756.34j) Ohms, VSWR=3.95, SL=16.95 dB 84 7.58dBi, 16.93dB F/B, Z=(31.7856.32j) Ohms, VSWR=3.95, SL=16.95 dB 623 7.58dBi, 16.93dB F/B, Z=(31.7856.28j) Ohms, VSWR=3.95, SL=16.95 dB What is what in the .up fileThe first column is an integer specifying the iteration. The other columns, going from left to right are gain(dBi), FB, input impedance, VSWR and level of the most significant sidelobe, in dB down on the peak gain.SEE ALS0yagi(1), output(1), input(1), optimise(1), first(1) and yagi(5).AUTHORSDr. David Kirkby G8WRB (david.kirkby@onetel.net), with help with converting to DOS from Dr. Joe Mack NA3T (mack@fcrfv2.ncifcrf.gov).
Visit the GSP FreeBSD Man Page Interface. 