The Designer's Guide Community Forum

The Designer's Guide Community Forum
https://designers-guide.org/forum/YaBB.pl
Design >> RF Design >> Basic Receiver module
https://designers-guide.org/forum/YaBB.pl?num=1270238691

Message started by Muss on Apr 2^nd, 2010, 1:04pm

Title: Basic Receiver module
Post by Muss on Apr 2^nd, 2010, 1:04pm

I am working on a project for school and as part of the project we have to send a wireless signal from one module to another. I have a transmitter that is generating a 3MHz signal. I just need a proof of concept so I just need to get the receiver to detect the signal reliably at a distance of a couple of feet. A group member has tried to design a receiver that is just a long wire feeding a passive bandpass filter, but it isn't giving a reliable result even after I have added a opamp to amplify the signal from the antenna. Can anyone give some advice on a very rugged design that we can implement to be able to send our signal a couple of feet away, if so I would really appreciate it. Thanks in advance!

Title: Re: Basic Receiver module
Post by aaron_do on Apr 3^rd, 2010, 7:36pm

Hi,

you could try a few things.

1) directly connect the transmitter to the receiver using a wire just to check that the everything is working. Or you could directly feed an input into the receiver from a signal generator, and also directly measure the transmitter output using an oscilloscope.

2) after doing the above, make sure the bpf center frequency is correct.

3) Maybe the antenna (a wire?) isn't long enough. Maybe it's not pointing in the right direction. If they're just wires I believe they should both be pointing up.

cheers,
Aaron

Title: Re: Basic Receiver module
Post by loose-electron on Apr 4^th, 2010, 6:59am

at 3MHz your wavelength is longer than the distance you are trying to communicate. Hmmm... Not sure what to suggest here.

Title: Re: Basic Receiver module
Post by ACWWong on Apr 4^th, 2010, 9:13am

hi muss,

you're better off doing infra-red to get a wireless link.

a transmitter with an infra-red LED
a receiver with PIN diode and then opamp/bandpass filter

best of luck with it.

cheers
aw

Title: Re: Basic Receiver module
Post by Muss on Apr 6^th, 2010, 8:29am

I appreciate all of your suggestions, but I realized one of the problems was with the opamp that I was using was designed for small signals. I am in the process of getting a opamp for larger RF frequencies so when I get it hopefully most of my problems will be fixed. If not I will be back. Thanks again for your help!