Problem solved. I changed the test fixture and made it as small as possible and added more absorber to try to get rid of any reflections that might be occurring. I got the results that were expected and was able to repeat the results. Thanks for all the help and suggestions.
I don't know when the chamber was last examined, but I do know that it has a flat field of about 5 feet. I am well inside of that. It is completely enclosed and lined with absorber. I am going to give it another whack tomorrow morning and try some different setups. If all else fails I'll...
Yes, I agree. I have moved the panel towards the transmitter. The standard test is moving by 1/4 wavelength and then averaging the results. I still come up with the same results of an increase in received power. I think that it is obviously a testing error. Otherwise I have created a panel...
No, the fabrication process is strictly controlled. I don't think that it's a problem with the panel. I think that the problem is in the test. I just haven't been able to isolate it yet. My next idea is to simply test the panel outside the chamber using a different setup. I'm thinking of...
I am dealing with EM the panel will ultimatley be a radome. That is if I can get some data that makes more sense. I am a student soon to be engineer someday and have looked in the IEEE archives and other handbooks but have found nothing on the topic which makes me believe that I am making a...
I am testing a composite panel in an anechoic chamber. I have a transmit antenna at one end and a receive antenna(horn) mounted to a positioner at the other end. The chamber is about 20 feet long. I record a reference power level. After recording the reference I place a flat composite panel...
I don't recall what the dielectric constant is. I am testing at 16 GHz. However, yes the reflections do match what the reflection coefficient would be. signal is increasing at some angles by 0.1- 0.2 db. loss in the panel should be no more than 0.3 db, which is what the results indicate. I...
In testing the loss through a fiberglass panel I experienced instances where the received power level increased. I have checked and double checked my setup and changed the distances between the horn and panel, I still am seeing odd results. Has anyone had any experiences such as this. I am...
It is referring to the plane of incidence. So I think that if I have a vertically polarized source horn and cut in the h plane then I am parallel to the plane of incidence on a flat panel. It is still a little coudy, but I think that is correct.
I am reading a book about radomes and am confused about what is meant by parallel and perpendicular polarizations. I am familiar with vertical and horizontal. I am having trouble determining the connection between them. Anyone?