  This manual is divided into two different parts:
    - Horns section user's guide.
    - Reflectors section user's guide.


  A. HORNS USER'S GUIDE:

  The main window has a menu with all action and commands the program can execute:

  Menu:
  * Print:
  The radiation pattern of the designed horn is obtained using the printer predetermined by Windows. Depending on the option you have selected the radiation pattern will be shown using Cartesian or polar coordinates.
  It is also printed the value of directivity, beamwidth, phase center and spillover efficiency, as well as input data, that is to say, horn dimensions, operating frequency and pattern phi-cut angle.
  * Reflector:
  Changes to the reflectors design part.
  * Exit:
  Exits the program.

  Horn:
  Selects the kind of horn you need:
  Rectangular (smooth-wall) horns:
  * H-plane sectoral horn.
  * E-plane sectoral horn.
  * Pyramidal horn.
  Circular (smoth-wall) horns:
  Corrugated horns:
  * Pyramidal horn.
  * Circular horn.

  Options:
  * Frequency:
  It lets you select the operating frequency (GHz), or alternatively, the wavelength (cm).
  The entered frequency value must make sure that the mode in the waveguide is not cut off. Otherwise a message will be shown urging us to modify the operating frequency or the guide dimensions.
  * Theta:
  Sets the range of theta values shown in the radiation pattern. You can choose the top and the bottom values as well as the number of axis divisions or the steps among them.
  * Phi-cut:
  It allows you to choose the phi-cut angle you want to compute the radiation pattern of.
  * Field scale:
  Sets the options for the field axis: the range of values to be shown and the number of divisions as it was described in theta option.
  * Automatic:
  This option complements the previous one; the program automatically selects the larger scale for the field axis (with the selected number of divisions, -8 by default-) in order to adjust it to the higher and the lower field values in the computed theta range.
  * Beamwidth:
  The beamwidth x dB below the boresight value is calculated. That value, x, can be entered in a dialog box. Besides, you are allowed to turn it into the default value by pushing the Default button. Beamwidth, phase centre and spillover efficiency computations use that number.
  * XY:
  Changes to a Cartesian coordinates system.
  * Polars:
  Changes to a polar coordinates system, with theta taking values from -90º to +90º.
  * Rad. Power:
  Here you can select the method to acchieve the radiated power. There are two opcions:
    - Aperture: it is obtained from the fields crossing the horn aperture.
    - Pattern: it is obtained integrating the radiation pattern.
  * Points:
  Sets the number of points used to draw the radiation patterns. When you select a high number of points the program takes more time to draw the pattern since more points must be computed, but it will not improve the accuracy of the process.

  Model:
  Now you can choose the mathematical model, i.e., the Electromagnetic Equivalence Principle you want to use to compute:
  * First principle.
  * Second principle.

  Dimensions:
  According to the horn you are working with, a different dialog box is shown, where sizes of horns can be modified.

  Pattern:
  Draws the radiation pattern with the selected options in a new auxiliary window, whose size can be changed and maximized so that details can be noticed more easily.

  Compare:
  When the automatic option is off, you can use this command instead of the pattern one. It allows you to see the consequences of changing any horn dimension, the phi-cut angle, computing with a different Electromagnetic Equivalence Principle,... since the previous radiation pattern is not erased when the new pattern is drawn.

  Help:
  This user's manual is shown.

  OTHER ASPECTS:
  - When you are entering the horn dimensions, which must be entered in centimetres, the program will warn you if there is an incorrect value.
In fact, with pyramidal horns, the program tries to adjust one of the parameters so as to get a physically feasible horn. To achieve it, the E-plane phase error parameter (s) is adjusted after a change of any of the other dimensions of the horn to satisfy the identity: Rh=Re.
  However, the program lets you analyse those cases when this condition is not satisfied changing in the last moment the value of E-phase error, though a warning message will appear.

  - In the main window, you can see a diagram of the selected horn and the selected dimensions, so that you can check if everything is right.

  - When the operating frequency or the horn dimensions are changed, it is likely that a message appears telling us that the mode in the waveguide is cut off for the input data. Any of them (frequency or waveguide dimensions) should be changed because otherwise the program will not let us obtain the radiation pattern.

  - When the pattern option is selected the radiation pattern is drawn, but also the directivity, the beamwidth, the phase centre and the spillover efficiency for the entered level are displayed.

  - Beamwidth is calculated for the phi-cut plane selected, and this value is used as the reference to compute phase center and spillover efficiency. As a consequence, the results will be different depending on the phi-cut angle you use unless a symmetrical pattern is considered.

  - The program automatically updates the aspect of the pattern after selecting options which does not imply repeating the computation. Otherwise, the pattern option should be selected to update the results.


  B. REFLECTORS USER'S GUIDE:

  The main window has a menu with every action and commands the program can execute:

  Menu:
  * Print:
  The radiation pattern of the designed horn is obtained using the printer predetermined by Windows. Depending on the option you have selected the radiation pattern will be shown using Cartesian or polar coordinates.
  It is also printed the value of directivity, beamwidth, phase center and spillover efficiency, as well as input data, that is to say, horn dimensions, operating frequency and pattern phi-cut angle.
  * Horn:
  Changes to the horns design part.
  * Exit:
  Exits the program.

  Reflector:
  Selects the kind of reflector system you need:
  Cassegrain.
  Parabolic.
  Offset.
  Dual-offset:
    * Cassegrain.
    * Gregorian.

  Options:
  * Frequency:
  It lets you select the operating frequency (GHz), or alternatively, the wavelength (cm).
  * Theta:
  Sets the range of theta values shown in the radiation pattern. You can choose the top and the bottom values as well as the number of axis divisions or the steps among them.
  * Phi-cut:
  It allows you to choose the phi-cut angle you want to compute the radiation pattern of.
  * Field scale:
  Sets the options for the field axis: the range of values to be shown and the number of divisions as it was described in theta option.
  * Automatic:
  This option complements the previous one; the program automatically selects the larger scale for the field axis (with the selected number of divisions, -8 by default-) in order to adjust it to the higher and the lower field values in the computed theta range.
  * Beamwidth:
  The beamwidth x dB below the boresight value is calculated. That value, x, can be entered in a dialog box. Besides, you are allowed to turn it into the default value by pushing the Default button.
  * XY:
  Changes to a Cartesian coordinates system.
  * Polars:
  Changes to a polar coordinate system, with theta taking values from -90º to +90º.
  * Feed taper:
  You can enter the feed taper for the sub-reflector edge angle.
  * Polarization:
  This option lets you select the desired polarization:
    - Lineal.
    - Circular:
      * Clockwise.
      * Counter-clockwise.
  * Blockage:
    - None.
    - Feed: considers the blockage caused by the feed. This option will be disabled if the feed is not a real horn.
    - Other: allows you to enter the radius of an hypothetical circular blockage.
  * Feed defocusing:
  It lets you shift the feed in axial direction (axial defocusing) or lateral directions (lateral defocusing).
  * Feed missalignement:
  It lets you missalign the feed.
  * Points:
  Sets the number of points used to draw the radiation patterns. When you select a high number of points the program takes more time to draw the pattern since more points must be computed, but it will not improve the accuracy of the process.

  Model:
  Now you can choose the mathematical model, i.e., the Electromagnetic Equivalence Principles you want to use to compute:
  * First principle.
  * Second principle.

  Dimensions:
  According to the reflectors system you are working with, a different dialog box is shown, where sizes of reflectors and angles can be modified.

  Pattern:
  Draws the radiation pattern with the selected options in a new auxiliary window, whose size can be changed and maximized so that details can be noticed more easily.

  Compare:
  When the automatic option is off, you can use this command instead of the pattern one. It allows you to see the consequences of changing any reflector dimension, the phi-cut angle, computing with a different Electromagnetic Equivalence Principle,... since the previous radiation pattern is not erased when the new pattern is drawn.

  Aperture:
  The field distribution on the aperture of the antenna is computed and drawn.

  Geometry:
  The general aspect of the global system can be observed since a scaled drawing of the system is shown.

  Help:
  This user's manual is shown.

  OTHER ASPECTS:
  - All system dimensions must be entered in centimeters, and angles in degrees.

  - When you change from the horn designing section to the reflectors one, you will be asked whether you would like to use the designed horn or an ideal cos-q feed.

  - In the main window, you can see a diagram of the selected reflectors system and the selected dimensions, so that you can check if everything is right.


  - When the pattern option is selected the radiation pattern is drawn, but also the directivity, beamwidth, horn reflection ratio and blockage, aperture and spillover efficiencies are displayed.

  - Beamwidth is calculated for the phi-cut plane selected.
