Wireless Design Toolkit

Equations:

Calculators:

Converters:


Convert inches / millimetres

1 inch = 25.4 mm

inches

millimetres


Convert circumference / diameter

C = πD

Where:

diameter

circumference


Convert miles / metres

1 mile = 1609 metres

miles

metres


Convert feet / metres

1 foot = 0.3048 metres

feet

metres


Calculate free space loss

FSL = 36.5 + (20 log10(D / 1609)) + (20 log10f)

Where:

distance in metres

frequency in MHz

 

free space loss in dB

Wavelength in air

L = c(1 / f)

Where:


Wavelength in coaxial cable

L = vc(1 / f)

Where:


Coaxial impedance

Zo = {138 / sq_rt (E)}log10(D / d)

Where:


Velocity factor

v = 1 / sq_rt (E)

Where:


Period of the wave

t = 1 / f

Where:


Calculate potential range from maximum free space loss at 2.44Ghz

D = 10((FSL-104.2) / 20)1609

Where:

free space loss in dB

 

distance in metres

Calculate effective radiated power

transmit power in dBm

cable losses in dB

antenna gain in dBi

 

effective radiated power in dBm

effective radiated power in mW

Calculate system operating margin or fade margin

transmit power in dBm

transmitting antenna gain in dBi
(including cable loss)

receiving antenna gain in dBi
(including cable loss)

receiver sensitivity in dBm

free space loss in dB

 

fade margin in dB

Convert milliWatts / dBm

milliWatts = 10(dBm/10)

milliWatts (mW)

dBm


Copyright © 2002. Author: Dave Gough (spacepleb@psand.net).
Psand Limited, 54 Goodwin Road, Ramsgate, Kent, CT11 0JJ, United Kingdom.

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA