Version 18 of Rectangular Radio Antenna and etcl Slot Calculator Demo Example

Rectangular Radio Antenna and eTCL Slot Calculator Demo Example

This page is under development. Comments are welcome, but please load any comments in the comments section at the bottom of the page. Please include your wiki MONIKER in your comment with the same courtesy that I will give you. Its very hard to reply intelligibly without some background of the correspondent. Thanks,gold

Introduction

gold Here is some eTCL starter code for calculating rectangular antennas from source frequency and other dimensions. The impetus for these calculations was designing rectangular antennas. Most of the testcases involve modeled data, using assumptions and rules of thumb .

The hentenna is a rectangular radio antenna with a cross bar tie for antenna leads. The original hentenna was designed for short wave frequencies on the order of 20 to 50 megahertz. Given a design frequency in megahertz, the various dimensions and proportions of the radio antenna are cut at heigth of wavelength(1/2), width of wavelength(1/6), and cross tie of wavelength(1/10). For simplified calculations, the radio wavelength in meters is equal to the speed_of_light in kilometers per second (300) over the radio frequency in megahertz. For an example of a receiving antenna for 100 megahertz and rounded numbers, the expressions below can be pasted into the eTCL console:

           namespace path {::tcl::mathop ::tcl::mathfunc}
           set megafrequency 100.
           set wavelength [/  300. $megafrequency ]  
           set wavelength2 [/ $wavelength 2.]
           set wavelength6 [/ $wavelength 6.]
           set wavelength10 [/ $wavelength 10.]

Testcases Section

In planning any software, it is advisable to gather a number of testcases to check the results of the program. The math for the testcases can be checked by pasting statements in the TCL console. Aside from the TCL calculator display, when one presses the report button on the calculator, one will have console show access to the capacity functions (subroutines).

Testcase 1

quantity	calc output	hand solution	comment
frequency megahertz	500.	500.	input
antenna height meters	.3	.91	output
antenna width meters	.1	.28	output
tie bar height	.06	.21	output

Testcase 2

quantity	calc output	hand solution	comment
frequency megahertz	144.	144.	input
antenna height meters	.34	.314	output
antenna width meters	1.04	.824	output
tie bar height	.208	.219	output

Testcase 3

A hentenna designed for 99.7 mhz was built from half inch copper pipe. The antenna had sufficiently narrow beamwidth to distinguish between two FM broadcast transmitters about 10 degrees azimuth apart. The hentenna has a horizonally polarized output. The horizontal output cancels out some of the urban noise environment, since many broadcast signals are vertically polarized.

quantity	calc output	hand solution	comment
frequency megahertz	99.7	100.	input
antenna height meters	1.5	.31	output
antenna width meters	.5	.11	output
tie bar height	.3	.6	output

Testcase 4

quantity	calc output	hand solution	comment
frequency megahertz	150	150	input
antenna height meters	1.	.9	output
antenna width meters	.3	.31	output
tie bar height	.2	.25	output

Testcase 5

quantity	calc output	hand solution	comment
frequency megahertz	50.	50.	input
antenna height meters	3.	3.1	output
antenna width meters	1.	.9	output
tie bar height	.6	.61	output

Screenshots Section

figure 1.

figure 2.

figure 3.

figure 4.

figure 5.

References:

Antennas, Balanis

Appendix Code

appendix TCL programs and scripts

         # pretty print from autoindent and ased editor
        # rectangular radio antenna calculator
        # written on Windows XP on eTCL
        # working under TCL version 8.5.6 and eTCL 1.0.1
        # gold on TCL WIKI , 9feb2014
        package require Tk
        namespace path {::tcl::mathop ::tcl::mathfunc}
        frame .frame -relief flat -bg aquamarine4
        pack .frame -side top -fill y -anchor center
        set names {{} {frequency megahertz:} }
        lappend names {answer: wavelength meters:}
        lappend names {wavelengthsq  meters sq: }
        lappend names {surface area meters sq: }
        lappend names {answer: antenna height meters}
        lappend names {antenna width meters:}
        lappend names {cross tie height meters: }
        foreach i {1 2 3 4 5 6 7} {
    label .frame.label$i -text [lindex $names $i] -anchor e
    entry .frame.entry$i -width 35 -textvariable side$i
        grid .frame.label$i .frame.entry$i -sticky ew -pady 2 -padx 1 }
        proc about {} {
            set msg "Calculator for Rectangular Radio Antenna
            from TCL WIKI,
            written on eTCL "
            tk_messageBox -title "About" -message $msg } 
        proc calculate {     } {
            global answer2
            global side1 side2 side3 side4 side5
            global side6 side7 testcase_number 
            global wavelength wavelength2 
            global wavelength6 wavelength10
            global wavelengthsq surfacearea  
            global megafrequency
            incr testcase_number
            set megafrequency $side1
            set wavelength [/  300. $megafrequency ]
            set wavelength2 [/ $wavelength 2.]
            set wavelength6 [/ $wavelength 6.]
            set wavelength10 [/ $wavelength 10.]
            set wavelengthsq [* $wavelength2 $wavelength2 ]
            set surfacearea [* $wavelength2 $wavelength6 ]
            set side2 $wavelength
            set side3 $wavelengthsq
            set side4 $surfacearea
            set side5 $wavelength2
            set side6 $wavelength6
            set side7 $wavelength10
            }
        proc fillup {aa bb cc dd ee ff gg} {
            .frame.entry1 insert 0 "$aa"
            .frame.entry2 insert 0 "$bb"
            .frame.entry3 insert 0 "$cc"
            .frame.entry4 insert 0 "$dd"
            .frame.entry5 insert 0 "$ee"
            .frame.entry6 insert 0 "$ff"
            .frame.entry7 insert 0 "$gg"}
        proc clearx {} {
            foreach i {1 2 3 4 5 6 7} {
                .frame.entry$i delete 0 end } }
        proc reportx {} {
            global side1 side2 side3 side4 side5
            global side6 side7 testcase_number 
            global wavelengthsq surfacearea
            global megafrequency
            console show;
            puts "testcase number: $testcase_number "
            puts "frequency (f) megahertz: $side1 "
            puts "wavelength (w) meters: $side2 "
            puts "wavelengthsq (w*w) meters sq: $side3 "
            puts "surfacearea meters sq (h*w) : $side4 "
            puts "wavelength/2 meters: $side5 "
            puts "wavelength/6 meters: $side6 "
            puts "wavelength/10 meters: $side7 "
            }
         frame .buttons -bg aquamarine4
        ::ttk::button .calculator -text "Solve" -command { calculate   }
        ::ttk::button .test2 -text "Testcase1" -command {clearx;fillup 146. 2. 1. .35 1.0981  .34 .205 }
        ::ttk::button .test3 -text "Testcase2" -command {clearx;fillup 99.7 3.2 2.2 .75 1.5  .5 .3 }
        ::ttk::button .test4 -text "Testcase3" -command {clearx;fillup 500. .6 .09 .03 .28  .1 .06 }
        ::ttk::button .clearallx -text clear -command {clearx }
        ::ttk::button .about -text about -command about
        ::ttk::button .cons -text report -command { reportx }
        ::ttk::button .exit -text exit -command {exit}
        pack .calculator  -in .buttons -side top -padx 10 -pady 5
        pack  .clearallx .cons .about .exit .test4 .test3 .test2   -side bottom -in .buttons
        grid .frame .buttons -sticky ns -pady {0 10}
        . configure -background aquamarine4 -highlightcolor brown -relief raised -border 30
        wm title . "Rectangular Radio  Antenna Calculator "

Pushbutton Operation

For the push buttons, the recommended procedure is push testcase and fill frame, change first three entries etc, push solve, and then push report. Report allows copy and paste from console, but takes away from computer "efficiency".

For testcases in a computer session, the eTCL calculator increments a new testcase number internally, eg. TC(1), TC(2) , TC(3) , TC(N). The testcase number is internal to the calculator and will not be printed until the report button is pushed for the current result numbers (which numbers will be cleared on the next solve button.) The command { calculate; reportx } or { calculate ; reportx; clearx } can be added or changed to report automatically, but is not recommended as computer efficiency is impaired. Another wrinkle would be to print out the current text, delimiters, and numbers in a TCL wiki style table as

  puts " %| testcase $testcase_number | value| units |comment |%"
  puts " &| volume| $volume| cubic meters |based on length $side1 and width $side2   |&"

Initial Console Program

        # pretty print from autoindent and ased editor

Comments Section

Please place any comments here, Thanks.

Category Numerical Analysis