Antenna for MICS Band

[ccwjames]

Hi, I am looking for antenna used for Medical Implant Communication Service Band. May I know which manufacturers design such antennas? Thanks

 

[ferdows]

its easy to design you can design it too but if u want to buy you can fine in Kathrein-Scala web site

 

[ccwjames]

its easy to design you can design it too but if u want to buy you can fine in Kathrein-Scala web site

I had gone through the web site but can't find any antenna for MICS band? Any other recommendation?

 

[Mark W. Ingalls]

It's just that you need to look for "UHF", James, instead of "MICS". Or look for "401-406 MHz.

(BTW, I have done a few "low profile" designs at those frequencies...)

 

[ccwjames]

It's just that you need to look for "UHF", James, instead of "MICS". Or look for "401-406 MHz.

(BTW, I have done a few "low profile" designs at those frequencies...)

Hi Mark, yes I did look through all the antenna at this website **broken link removed**

but most of them are too big as i need the antenna for medical device which is very small and able to implant into human body.

Any other suggestion?

 

[Mark W. Ingalls]

Hi Mark, yes I did look through all the antenna at this website **broken link removed**

but most of them are too big as i need the antenna for medical device which is very small and able to implant into human body.

Any other suggestion?

For that, you will need something like this: **broken link removed**

Is this a research project? I only know of such antennas as being implemented by the medical equipment vendors; each application is custom made (in my experience), so there is not likely to be anything available commercially of the shelf.

 

[ccwjames]

Hi Mark,

Thanks for the info. The antenna design by Kiourtni & Nikita indeed very small. I have tried to do some simulation using CST MWM and found something.

The antenna will have good response at 403MHz if it is place inside human body openly without any casing/capsule. If I include a casing/capsule then the antenna will have big differents response and the excitation maybe falls in few GHz. Any idea?

 

[Mark W. Ingalls]

Hi Mark,

Thanks for the info. The antenna design by Kiourtni & Nikita indeed very small. I have tried to do some simulation using CST MWM and found something.

The antenna will have good response at 403MHz if it is place inside human body openly without any casing/capsule. If I include a casing/capsule then the antenna will have big differents response and the excitation maybe falls in few GHz. Any idea?

One idea is that you have probably changed the dielectric constant and loss tangent of the medium in which the antenna is immersed, yes?

 

[ccwjames]

Nope, nothing changed. Just that the antenna needs to have direct contact with medium with high Er value(example human tisuue Er=46.7). If I put the antenna inside a capsule with low Er, and after that this capsule is immersed in medium with high Er, it will not work this way as the resonance change completely. Is this normal?

 

[Mark W. Ingalls]

One idea is that you have probably changed the dielectric constant and loss tangent of the medium in which the antenna is immersed, yes?

Nope, nothing changed. Just that the antenna needs to have direct contact with medium with high Er value(example human tisuue Er=46.7). If I put the antenna inside a capsule with low Er, and after that this capsule is immersed in medium with high Er, it will not work this way as the resonance change completely. Is this normal?

...erm, except you just described the change I asked you about. The antenna is immersed in a low Er medium (your capsule) which is in turn immersed in tissue.

Yes, it is completely normal that the frequency would go up when the Er surrounding the metal parts is reduced.

 

[ccwjames]

If this is the case then how we gonna have a very small antenna that resonate at 403MHz if we were to put the antenna inside a capsule and then immerse in tissue? or this is just a simulation error? which we should simulate just the antenna and not with the capsule?

 

[Mark W. Ingalls]

Sorry, ccwjames, I've been travelling.

I am "pretty sure" that what you are simulating is not an error, at least the Er part. If you filled your capsule with a high Er material, similar to tissue in character, wouldn't you expect the frequency come back down?

Perhaps it might be a good idea for you to do some reading about planar antennas loaded by dielectrics.

If this is the case then how we gonna have a very small antenna that resonate at 403MHz if we were to put the antenna inside a capsule and then immerse in tissue? or this is just a simulation error? which we should simulate just the antenna and not with the capsule?