26-07-2012, 01:18 PM
short range wireless communication
[attachment=29051]
What’s on the CDROM
Included on the CDROM accompanying this book are twelve radio
engineering worksheets. Throughout the text, sections that have an accompanying
worksheet are indicated by this icon: . These worksheets will
help you solve a wide variety of problems and should be of assistance to
you in radio system design. The worksheets are based on Mathcad, a popular
mathematics program published by MathSoft in which formulas and data
are entered in familiar mathematical format, just as they would be when
solving problems using pencil and paper or writing on the blackboard.
In order to use the worksheets you must have Mathcad 8 Professional
version or higher installed on your computer. A free version of
Mathcad Explorer, a read-only version of Mathcad 8 Professional, can
be installed from MathSoft’s website. A link to their site has been
provided on the CDROM.
Once Mathcad Explorer has been installed on your system, run the
program. Click “File”, “Open...”, from the tool bar, then select the
“Mathcad Worksheets” folder from the CDROM. From “Files of type...”
choose “Mathcad Files (*.mcd).” Open a worksheet.
The Mathcad web site, www.mathcad.com, has a library of engineering
worksheets that you can access and work on using the Mathcad Explorer.
Using the Worksheets
As stated above, Mathcad formulas appear in normal written form
on the worksheets. There are some small differences in interpretation of
symbols. For example, a data entry expression is made up of a variable
on the left, followed by a special equal sign which looks like a colon and
an equals sign as follows := . An equals sign alone is followed by a
calculated answer. It’s worthwhile to study the HELP contents in order
to benefit most from the worksheets, as well as to do your own mathematical
calculations.
Graphs
A couple of the worksheets have graphs. If you want to find a
particular coordinate and the resolution of the axes is not sufficient,
click on the graph with the right mouse button. Click on Trace. Move
the cursor on the plot and see the coordinates in the Trace window.
Units of Measure
One of the special features of Mathcad is the ease of using units of
measure. You don’t have to use any conversion factors when changing
units. For example, if the default unit of length in a yellow data input
expression is cm (centimeters) and you prefer to enter your data in
inches, simply insert the number of inches, then replace “cm” with “in.”
Similarly, the units of measure in the blue solution expressions can also
be replaced.
Helical.mcd — Helical Antennas
Helical antennas are commonly used for portable short-range transmitters
and receivers, and you can get a good start on the design of one
using this worksheet. After you insert the global parameters — frequency,
antenna diameter, and wire diameter—you have two choices for
the remaining data. If you know the turns per inch of the winding for the
antenna, start from section (1) and insert the data. The antenna height
will then be calculated. In section (2) right click on the yellow expression
for height, then click “Disable Evaluation” in the pop-up window.
Check sections (3) through (7) to see the results of your design.
If both the height and the diameter of the antenna are known, enter
the height in the yellow expression under (2). (If the expression had
been disabled as shown above, there will be a small black rectangle in it.
Right click on it and click “Enable Evaluation.”) The required number
of turns for resonance will be shown in the blue expression. Get more
information from sections (3) through (7).
[attachment=29051]
What’s on the CDROM
Included on the CDROM accompanying this book are twelve radio
engineering worksheets. Throughout the text, sections that have an accompanying
worksheet are indicated by this icon: . These worksheets will
help you solve a wide variety of problems and should be of assistance to
you in radio system design. The worksheets are based on Mathcad, a popular
mathematics program published by MathSoft in which formulas and data
are entered in familiar mathematical format, just as they would be when
solving problems using pencil and paper or writing on the blackboard.
In order to use the worksheets you must have Mathcad 8 Professional
version or higher installed on your computer. A free version of
Mathcad Explorer, a read-only version of Mathcad 8 Professional, can
be installed from MathSoft’s website. A link to their site has been
provided on the CDROM.
Once Mathcad Explorer has been installed on your system, run the
program. Click “File”, “Open...”, from the tool bar, then select the
“Mathcad Worksheets” folder from the CDROM. From “Files of type...”
choose “Mathcad Files (*.mcd).” Open a worksheet.
The Mathcad web site, www.mathcad.com, has a library of engineering
worksheets that you can access and work on using the Mathcad Explorer.
Using the Worksheets
As stated above, Mathcad formulas appear in normal written form
on the worksheets. There are some small differences in interpretation of
symbols. For example, a data entry expression is made up of a variable
on the left, followed by a special equal sign which looks like a colon and
an equals sign as follows := . An equals sign alone is followed by a
calculated answer. It’s worthwhile to study the HELP contents in order
to benefit most from the worksheets, as well as to do your own mathematical
calculations.
Graphs
A couple of the worksheets have graphs. If you want to find a
particular coordinate and the resolution of the axes is not sufficient,
click on the graph with the right mouse button. Click on Trace. Move
the cursor on the plot and see the coordinates in the Trace window.
Units of Measure
One of the special features of Mathcad is the ease of using units of
measure. You don’t have to use any conversion factors when changing
units. For example, if the default unit of length in a yellow data input
expression is cm (centimeters) and you prefer to enter your data in
inches, simply insert the number of inches, then replace “cm” with “in.”
Similarly, the units of measure in the blue solution expressions can also
be replaced.
Helical.mcd — Helical Antennas
Helical antennas are commonly used for portable short-range transmitters
and receivers, and you can get a good start on the design of one
using this worksheet. After you insert the global parameters — frequency,
antenna diameter, and wire diameter—you have two choices for
the remaining data. If you know the turns per inch of the winding for the
antenna, start from section (1) and insert the data. The antenna height
will then be calculated. In section (2) right click on the yellow expression
for height, then click “Disable Evaluation” in the pop-up window.
Check sections (3) through (7) to see the results of your design.
If both the height and the diameter of the antenna are known, enter
the height in the yellow expression under (2). (If the expression had
been disabled as shown above, there will be a small black rectangle in it.
Right click on it and click “Enable Evaluation.”) The required number
of turns for resonance will be shown in the blue expression. Get more
information from sections (3) through (7).