tape.art

一个很小和天线计算程序

SUBJECT:  Tape Antennas

       Thanks goes to Jim Grubs for the idea.  

       Tape antennas seem to be an interesting way for apartment dwellers,
travelers, and others who need a quick antenna that can be used locally.

       For these experiments I used copper tape, 1/2-in wide for my tests.
       The following antenna types were tested:

               o       J-Pole
               o       Half-wave Dipole
               o       Full-wave Loop

       Tape antennas are not new.  I haven't seen much about tape antennas
with the exception of SAREX, used aboard the Shuttle.  Even this antenna
was quasi-tape-type. 

       In general, the tape antennas had some interesting propagation 
results due to the location of testing.  Locally, the antenna is excellent.
Within a mile or two, the antenna works as well as an outside antenna.  But,
due to the single floor building I work in these results may be better
if the antenna was located on a higher floor. 

       Propagation outside the local area was a function of which way the
window faces.  Generally, the antenna pattern was not omni, but rather an
attenuated omni pattern to the side where the building faces.

       Figure 1:  Signal levels in dBm.

 -21           -20        -17     1      12     16          18



 -21                                                              21
                       ------------                        
                       |          |                         
 -22                   |          |                                 23
                       |          |X                        
                       |          |                                 24
                       |          |                          
                       |          |                                 22
 -21                   ------------                          

                                                              19

-22          -19          -16         2        11         17



       These were the results of the Half-wave Dipole.  Input level was 
30dBm, CW, at 145 MHz.  I hope FIDO didn't screw up the picture.  The 
distance from the building was taken at 100 feet using an EMC testing
dipole and an HP-8562 spectrum analyzer.  Coax was a 72" section of 
Adams-Russell 1999-0072 with precision 'N' connectors.

       All readings were taken at ground level (standing there normally).
The transmitter was placed in a window at 4-ft off the ground at the feed.

       Further results will be posted after I finish testing a few other
designs.


-WS