Insulating Liquids for Antenna Measurement

I am conducting some measurement for implanted antennas.
And I need some insulating liquids (to insulate antenna with environment) which have permittivity 10 and 18?
Can you suggest me some liquids like that?

Many thanks

Hi,

i′m sorry i can′t help you with a liquid name.
But if you′re thinking of 2 component coating then be careful, because the permittivity varies with temperature.

Klaus

Water relative dielectric constant is there around at 50GHz and 25*C.
Conductivity is also an important antenna factor.
If knowing frequency and temperature and what body parts that will be involved, dielectric and conductive proprieties can be found at this site: http://niremf.ifac.cnr.it/tissprop/h...e/htmlclie.htm
Other sources may give minor variations of these values, and some sources have separate tables for man, child and woman.
Making a solution with similar properties as body tissue is commonly done by adding salt(NaCl) in a sugar and water solution.
Some common mixtures can be found here, p38: http://www.fcc.gov/Bureaus/Engineeri...t65/oet65c.doc
FCC's dielectric values are given for whole body-parts, not a certain tissue.
Mix boiling water and sugar and let cool down to room temperature.
Check dielectric value. I use a VNA for that.
Adjust by adding water or another water/sugar mixture. Do never add pure sugar, it will take forever to melt and become stable.
Finally add small amount of almost saturated salt-water for correct conductivity. Do not add pure salt directly.
If need to adjust, it requires a lot of slow stirring. To fast stirring and air-bubbles are added, which gives a unstable solution.
Add something that stops fermentation, which else changes electrical properties.
Observe that electrical properties changes with temperature also for final solution.

looks like ammonia is pretty close:

http://www.engineeringtoolbox.com/li...ts-d_1263.html

what about using:
Silicon epsilon = 11 - 12.
BUTANOL Eps =17.8 (at 68 degree K)
ALCOHOL, INDUSTRIAL Eps = 16 -31;
AMYL ALCOHOL Eps =15.8 (at 68 degree K)
CASTOR OIL (HYDROGENATED) Eps =10.3 (at 80 degree K).

These liquids need to be almost perfect insulating. The test is conducted at 400 MHz, 20-25 degree C.
How can I know the electrical conductivity of organic substances? I have a table for dielectric constant of many substances.
Many thanks

Why do you want insulating fluids? That is not how most body fluids behave.
Conductivity of body fluids and tissues was given in the table previously provided http://niremf.ifac.cnr.it/tissprop/h...e/htmlclie.htm

Thank E Kafeman very much.

I my experiment, I need both 2/3 tissue-simulating fluid and insulating fluids.

I have recipe for making 2/3 tissue-simulating fluid as you showed me already.

I also need insulating fluids to insulate antenna from 2/3 tissue-simulating fluid. Insulating fluids work as insulators for implanted antenna. That's the way my antenna works.
How can I know the electrical conductivity of organic substances as I showed in my pdf file.

Thanks

Deionized water have very low conductivity at 400 MHz. Mix it with sugar for a certain level of dielectric constant. Sugar have minimal effect of solution conductivity.