quaternion
Joined: 12 Nov 2006
Posts: 201
Helped: 11
Location: Cairo , Egypt
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 03 May 2007 0:53 suitable transmitter type and design |
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I am not sure that I post at the right place.
I am new in the field of transmitting and recieving.
The transmitter is a wireless one.
It is a part of a project and not stand alone one and so minimizing complexity and cost is a must. It is used as a control for a semi on-off operation.It is contained in a device (also under design and can be changed) that operates with a PIC micro-controller that checks for a secret code and if the code is right control is enabled,and the Tx transmitt signals that control the on-off operation which is also controlled by a PIC µC(i.e. a Rx give the info to the PIC and the PIC controls the operation ).Noting that there are other work in the same project that i didn't talk about so the design needed to be less complex as I said before.Also notnig that the PICs are small ones that are used in normal control applications.
So in order to minimize Rf problems I was recommended to work at 1MHz carrier. As a start I think to transmit the digital info as ASK(amplitude shift keying) but I face some problems that make me to rethink about the modulation type to be used.Also the transmitter and its PIC info source are wanted to operate with a DC source in the range of 9 to 12 V (is this sufficient knowing that the transmitter operating range is no more than 20 meters).Also I decided to use a class AB power amplifier to drive the antenna, which is choosen to be a normal loop antenna (coil around a ferrite rod).
Which modulation type is recommended in this case and if a suitable IC for modulation and mixing is available please I need its no.
And many thanks in advance.
I forgot to say some thing the available time to finish the whole project is 2 weeks.
(It seems to me impossible but I have no choice0
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