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Original antennas made in the US, by us, for the greater World

In response to a number of requests for a passive antenna booster, or simple means to enhance the range of a cordless phone, a mobile phone (cell phone), a local WLAN (Wi-Fi), or any other low power radio device, particularly in rural and cellular fringe areas, herein are some possible solutions available. To help you assess how to best achieve your desired goals, below are links to range estimation charts derived from an old, but generally trustworthy propagation model developed many years ago for our own internal use. Charts are provided for the key ISM bands of 900 MHz, 2.4 GHz and 5.8 GHz. If your application lies at other frequencies, use the chart nearest your band of interest. We will add other charts as we receive requests to do so.


915 MHz chart     2.4 GHz chart     5.8 GHz chart


Instructions for the use of the above charts are at the bottom of this page. Three typical case studies are evaluated in the following links to review the potential benefit of a Passive Booster system. You can augment the performance of a Passive Booster through the strategical addition of a bi-directional amplifier. Such devices will be offered here by early 2008 and we will expand these instructions to include directions on how to add a bi-directional amplifier to a Passive Booster system.

Unsure about your calculations? When you buy a kit below, you will have the option to submit by FAX +1-954-345-5005 your calculations for us to check. You will also have the option to have us calculate the heights and ranges for you. Please use the form below (service and form available after Nov. 12).

This Category description and contents are under construction until Nov. 12


Instructions for the use of the above provided charts:

  • Two graphs are provided on each sheet, the top graph is for an installation having a long coaxial cable run of 30 meters (100 ft), while the bottom chart is for half that length, i.e. 15 meters (50 ft).
  • Each chart shows traces of different colors, one such trace is a flat line at -95.5 dBm. This line has been labeled "Sensitivity", corresponding to the assumed sensitivity of the receiver. The -95.5 dBm figure is a good average of typical receiver sensitivities across the 3 bands (0.9, 2.4 and 5.8 GHz).
  • The varying traces represent the signal strength at their corresponding range. Multiple curves of different colors relate to the signal strengths having the transmitter antenna height at 2, 4, 6, 8 and 10 meters (7, 13, 20, 26 and 33 feet) respectively. The model power output of the transmitter is 200 mW (1/5 Watt).
  • The receiver antenna is fixed at 1 meter (3 ft)
  • While the signal strength curve of the particular height is above the "Sensitivity" (horizontal) line, the communication system is operational (it works). Where the lines cross, that is the maximum range of the system. When the Signal curve is below the "Sensitivity" line, the communication system fails (it will not work)
  • NOTE: the MEI model used to produce these charts is generally conservative, so you may continue to enjoy communications beyond the estimated range. In real life, however, conditions exist that will modify model predictions up or down. In addition, your device may output more or less power, or its sensitivity may differ from the model provided. For these reasons and more, you should use the model results more as a "rule of thumb" or a good "educated guess". These results are never to be considered as guaranteed because there are so many factors affecting the performance of a radio link that cannot be included into a single pair of simple graphs.
  • You can move the "Sensitivity" line up or down the chart to tailor the given charts to your particular situation: for example, if your device produces 400 mW of RF output instead of the 200 mW of the model, you may lower the "Sensitivity" line by 3 dB (from -95.5 dBm to -98.5 dBm). Chart results are easily scalable in this fashion. Height changes are not scalable, but you can follow the trend from the various heights provided.
  • To convert power ratios to "dB"s (deciBells), you can use the following table:
    • 25% increase ==> add 1 dB
    • 100% increase (double) ==> add 3 dB
    • 1000% increase (10 times) ==> add 10 dB
    • 80% of original ==> subtract 1 dB
    • 63% of original ==> subtract 2 dB
    • 50% of original (half) ==> subtract 3 dB
    • 10% of original (1/10 th) ==> subtract 10 dB
  • Examples:
    • 150 mW power instead of 200 mW ==> 75%, which is between 80% and 63%, a good choice would be -1.5 dB (raise the Sensitivity line by 1.5 dB)
    • 800 mW power instead of 200 mW ==> 400% (or double 200 mW two times, each time add 3 dB) which is +6 dB (lower the Sensitivity line by 6 dB)
    • 400 mW power and -92.5 dBm of receiver sensitivity ==> add 3 dB for power output and subtract 3 dB of poorer receiver sensitivity = +3 dB + (-3 dB) = 0 dB (or no change)