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

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

Webmaster:

Kirt Blattenberger,

BSEE - KB3UON

RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The World Wide Web (Internet) was largely an unknown entity at the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps while tying up your telephone line, and a nice lady's voice announced "You've Got Mail" when a new message arrived...

All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged.

My Hobby Website: AirplanesAndRockets.com

My Daughter's Website: EquineKingdom