Foxwave Microwave Link Planner

Thank you for using the Foxwave Microwave link planner. This software solves some of the most common equations used when planning a radio link. The user interface is designed to be minimal and easy to use. Each tab performs a single function. User errors, such as entering non-numeric characters, too many decimal points, or entering 0 in a mandatory input are indicated by the input field for the bad entry turning red.

Installing and Running

Because Foxwave is written in Java, there is no need to install it, simply unzip the archive and save the Foxwave folder to your computer. I recommend saving it in your home directory. You must have Java installed on your computer. Click on the foxwave.jar file to run the application. If this doesn't work, you may need to configure your file associations so that .jar files are opened by Java, or run it from a command line with the command java -jar foxwave.jar.

If you are using Windows you may want to create a shortcut to this file so that you can launch it from your desktop or start menu.



Save and Print Features

Foxwave allows you to print or save the results of a calculation in a nicely formatted document. The calculation is printed with a bold heading and enclosed in a table for easy readability. For record keeping purposes, a footer is added to each printed or saved page with today's date and the name of the user who printed it.

When printing or saving, a dialog box appears asking if you would like to add notes, which will be inserted at the bottom of the document, between the calculation and the footer. Press OK to save your notes. Press cancel or leave the text field empty if you don't want to add notes.

The results of a calculation can be saved by clicking File then Save. Enter a name for your file and click Save. The file will be saved as an HTML document containing the title of the calculation being done, all of the user entered variables, and the calculated results. For the Conversions tab, only the results of the last calculation will be saved.

To print a document, click File then Print. A window appears with a print preview, along with a printer dialog that allows you to select any print options. Do not close the preview window until printing is complete. The preview window will close on its own.



Path Loss and RSL Tab

To calculate Free Space Path Loss, only two fields need to be filled in: Distance, and Frequency. The rest can be left blank. Filling in all of the fields gives you the real world performance of your link. To determine the received signal level you will need to fill in the Transmitter Power, and optionally the gain of the receiving and transmitting antennas and the losses associated with their feed lines. Loss figures to be expected from feed line components can be obtained from the manufacturer's datasheets. If a dipole is being used as an antenna, the antenna gain can be set to 2.15 dBi or 0 dBd to get the same results.



Antenna Calculations Tab

This tab allows you to calculate the gain, half-power (-3dB) beamwidth, and null beam width for your parabolic antenna. This function is useful for finding the gain of an antenna you don't have the specifications for, or estimating the size of antenna needed for a given link.

Results are given in degrees for the beamwidths. You can choose between decibels over an isotropic radiator (dBi) or decibels over a dipole(dBd) for the gain figure. Antenna manufacturers usually specify their equipment using the former. Efficiency varies depending on the type of antenna and manufacturer, and can be anywhere from 50 to 80%. The center-fed parabolic antennas, such as those produced by Andrew are the most commonly used for terrestrial links and typically have an efficiency of between 60% and 65%, while prime focus satellite antennas have an efficiency of approximately 73%.



Conversions Tab

Use this tab to calculate the wavelength of a given frequency or the frequency of a given wavelength. Inputs and outputs can be in imperial or metric for wavelength and in gigahertz or megahertz for frequency.

It should be noted that the results are rounded to two decimal places; The default setting of centimeters and gigahertz should be accurate enough for most uses, but when extra precision is required, millimeters and megahertz should be used.

The Frequency to Wavelength calculation includes an optional setting for velocity factor. This is a percentage between 50% (0.5) and 99% (0.99) that the speed of the wave in free space is multiplied by. It is used for modeling the speed of a wave in a transmission line such as a waveguide or coaxial cable and can be found in the datasheet from the manufacturer. Clicking the Free Space button disables the velocity factor and the wavelength is calculated using the speed of light in free space.

Transmit power can be converted to or from watts and milliwatts, as well as the logarithmic measurement dBm. Negative numbers can only be input when converting from dBm to watts or milliwatts.



Link Budget

This tool is used to estimate the equipment needed to acquire a given signal level at a remote site. Total System Losses is a number representing the signal lost to free space path loss which can be calculated using the Path Loss and RSL tab. Losses expected from transmission line components such as waveguide, coax, and connectors can be obtained from the manufacturer's datasheets. Required Received Signal Level is the desired signal level at the remote site expressed in dBm, and should be a margin above your receiver's nominal sensitivity. Both numbers are assumed to be negative, so it is not necessary to enter a - sign.

Total System Losses and Required Received Signal Level must be given, along with two of these three variables: Transmitter Power, Transmitting Antenna Gain, and Receiving Antenna Gain. The third value is then calculated and given on the right side of the tab under Calculated Link Requirements.



Legal and Copyright Information

This program is provided for free, as a tool for estimating the parameters of a radio link. It is not a substitute for an RF engineer. No warranty is given as to the results of this program, and your use of it is conditional to your implicit agreement to these terms of use. By accepting these terms of use you agree not to hold Revenstar, its employees, or affiliates liable for any damages, monetary or otherwise, that may result from the use of this program.

This program is © 2015 Revenstar and Planet Fox. The only websites authorized to offer downloads of this software are revenstar.net and planetfox.net and sites authorized by Revenstar.

To ensure a uniform look across different platforms, Foxwave comes with fonts and icons for the user interface elements. Bell Gothic Black is © AT&T and should not be distributed separately this program without permission from the authors.