Question about FM theory.. reception and transmission..

EDAboard.com Forum Index -> RF, Microwave, Antennas and Optics -> Question about FM theory.. reception and transmission..

Author

Message

ahmad_abdulghany

Joined: 12 Apr 2005
Posts: 1369
Helped: 212
Location: Cairo, Egypt

28 Apr 2006 0:15 ne564 application notes

Hello all

If I want to design and understand a WBFM Rx (and also a WBFM Tx), i think i should first know the available confgurations,
know the adv/disadvantages of each one,
choose one,
start to simulate it,
build circuit board,
test,
and finally debug it..

I think this is the logical way to make it or in general to build most of systems.. right?

Okay, Can anyone help me to follow the above steps to build a WBFM Rx with IF of 10.7MHz, and carrier frequency either 100MHz, 433MHz, or anyother frequency (i can use mixer after that to change carrier frequency)

Please help me but I'm sorry, I think it may be difficult to get ready kits or modules, i want to make my own circuit with discrete components (I may also be able to get either NE564 PLL or 74HC4046A PLL or TDA7000)

Also, I want to understand the circuit you give to me.. not only be able to build it, but to understand, simulate, and modify if possible..

You may help me by guiding me through the correct suggested way to flow in, not important to give me the ready made circuit, you may suggest useful application notes, books, papers, ...etc. or suggest steps, such as you say: go and read in demodulators in the ... link, then try to build a mixer....etc.
but please in the limit of my request..

Thanks alot in advance,
Ahmad,

ahmad_abdulghany

Joined: 12 Apr 2005
Posts: 1369
Helped: 212
Location: Cairo, Egypt

30 Apr 2006 15:10 Re: Question about FM theory.. reception and transmission..

Why no one replies??

Add even small comment

Thanks,

Ahmad,

Google
AdSense
Google Adsense

30 Apr 2006 15:10 Ads

mwmmboy

Joined: 18 May 2001
Posts: 145
Helped: 6

02 May 2006 13:16 Re: Question about FM theory.. reception and transmission..

Hi,
to start I suggest you to see the block diagram of an IC like SA636.
On the data sheet you can find information about hot to demodulate an FM signal with 10.7 MHz IF.
Basically you need to have the signal carring the FM information limited and the you have to pass it through a an FM demodulator.
You can find many configuration of an FM demodulator in nearly all electronics book.

I hope this can help you to start.

Bye.

boy

Joined: 30 Sep 2002
Posts: 563
Helped: 39

02 May 2006 14:11 Question about FM theory.. reception and transmission..

Most FM IC demodulation (such as SA636) use quadrature detector. The trick you have to find a good IF can from a reliable source. For detail about quadrature detection and IF can.

http://hem.passagen.se/communication/quadcoil.html