penetrating microwave (high frequency) on water. - RF Cafe Forums

The original RF Cafe Forums were shut down in late 2012 due to maintenance issues - primarily having to spend time purging garbage posts from the board. At some point I might start the RF Cafe Forums again if the phpBB software gets better at filtering spam.

Below are the old forum threads, including responses to the original posts.
-- Amateur Radio
-- Anecdotes, Gripes & Humor
-- Antennas
-- CAE, CAD, & Software
-- Circuits & Components
-- Employment & Interviews
 -- Miscellany
-- Swap Shop
-- Systems
-- Test & Measurement
-- Webmaster

elia_lyza
 Post subject: penetrating microwave (high frequency) on water.
Posted: Fri Dec 19, 2008 1:23 am 
 
Lieutenant

Joined: Thu Dec 18, 2008 10:56 pm
Posts: 4
Location: shah alam,selangor
is there any advantage or disadvantage when using microwave(high frequency) on water?
 
   
 
nubbage
 Post subject:
Posted: Fri Dec 19, 2008 12:22 pm 
 
General
User avatar

Joined: Fri Feb 17, 2006 12:07 pm
Posts: 268
Location: London UK
Hi Elia
From your other post it is clear you are making (permittivity??) measurements.
A lot depends on what is mixed with the water and in what ratio. As I mention in my previous post to you, I always used closed containers like coaxial or waveguide transmission support, or resonant cavities, and a Vector Network analyzer or other impedance bridge methods. Containing the field makes the measurement easier to set up and the results more accurate and repeatable, and the errors calculable with confidence.
The open tank free space approach is obviously important if the water is flowing and not static.
What are you considering for the Free Space Method? There are 2 or 3 ways to approach it in that case. What sort of frequency range are you using?




Posted  11/12/2012