How to design an antenna for undersea communication

[nisha dinakar]

How to design an undersea communication as the conductivity and permittivity changes.
please help me to find a software to work on.

 

[throwaway18]

Are you sure you want to use radio waves, not sound waves?
What frequency do you plan to use?
What range are you hoping to communicate over?
Click here for a page with a graph of loss per meter versus frequency in salt water. It suggests that at 400MHz the loss is about 30dB per meter, with typical radio system maximum path loss of 130 to 140dB you get four or five meters range. At 27MHz path loss about 2dB per meter so maybe 70meters but an efficient antenna will be large, bigger than a diver would like to carry.

Click here for another interesting article about underwater radio waves

 

[nisha dinakar]

I wish to do in MHz range frequencies.can u suggest software for this design. Many of the work done in this area are based on HFSS ,CST,FEKO. Since i have no funding agencies,I would like to go for a free ware for simulation .Please suggest how to start with.

Can any one help me with this.

 

[jiripolivka]

Forget about software and look for real data! SUbmarines do communicate by radio, with frequency from 12 to 70 kHz. Good antennas are either coils on ferrite cores or loops, the large continental stations use long peninsulas with buried wires as "short-wire" antennas. Loss is high, so be ready to transmit by kilowatts of power.

 

[nisha dinakar]

i like to design a bo w tie antenna with R$ epoxy substrate and copper as element.but getting few errrors.Any one please sent me a bow tie which work in any frequency short range with water_sea as the radiating space

 

[jiripolivka]

First find sea water permittivity to scale the size of your dipole. Next read again what I wrote above.

 

[godfreyl]

short range

How short? 1m? 2m? 10m? 50m? 100m?

 

[nisha dinakar]

How short? 1m? 2m? 10m? 50m? 100m?

distance is 10m