Microwave Laboratory

Preliminary Testing

During the early construction stage of the anechoic chamber, testing of the power meter and RF source were conducted by a summer student, Jonathan Langleben (Uni. Surrey). Two tests were conducted that involved recording power measurements using our TK THz Power Meter. The meter was attached to a Zaber motorised linear stage and a transverse scan was conducted for 4 different longitudinal positions. This was conducted for two different speeds. The two graphs below show the results of the scan. A copy of the data can be found in the Excel spreadsheet here or attached at the foot of the page.

1. mm/s Scan:
   

1. 5 mm/s Scan:
   

The first scan at 1mm/s clearly shows that the peak power varies with distance from source as expected, however the curves clearly aren't smooth. This is due to the stage being unable to maintain constant speed, resulting in the movement becoming staggered. The second scan at the higher speed provided a smoother curve.

There is also an apparent shift in peak intensity with longitudinal position, however this can be explained by the RF source module being at a a small angle with respect to the power meter. A 2D plot of the power is shown below.

* 2D Power Plot:

Further experiments are currently in progress to provide additional measurements with a more reliable linear stage.

References

* http://en.wikipedia.org/wiki/Gaussian_beam