Basic concepts and issues in RF design

[zeerum]

hi
i m a computer graduate and doing masters in rf communications
we were given little concept of rf and then given an assignment which carries 80 percent of our grades
since i have a litter background in this field so can anyone help me with basic issues and concepts in design...is there any one with whom i can discuss these things?
i have very little time to read books on it as there are four more subjects as well...so please dont advise me to read up on it now......i m reading about it but cant do more than that cause u know it would affect other subjects as well
so anyone?

 

[bcl]

Re: any rf expert here

Not sure there is any way around reading up on the subject; perhaps you would consider dropping one of the other classes? Good luck!

 

[VSWR]

Re: any rf expert here

Why do you believe RF & Microwaves can be learned without studies? There are no shortcuts...

 

[rectifier]

any rf expert here

Hey Zeerum, what help do you want from us??

 

[zeerum]

Re: any rf expert here

its not about shortcuts dear
we dont have background knowledge of that field...so they were supposed to teach us about that before giving us that task to accomplish....we were totally clueless where to start from when we were assigned that task....n it wasnt with me only....every body in class was going through same condition

anyways....thnx rectifier for an encouraging reply...i will post ma prob in next reply as m not having specifications with me right now

 

[zeerum]

Re: any rf expert here

hiya
well we have designed a single superhet receiver whose IF turns out to be 380 MHz

now we have to design a transmitter..the carrier frequency that we were given in specifications was 2.4GHz....n we designed our superhet according to it
now there is a dispute in our group about the frequency of modulation...two guys say that we need to modulate actual bit stream with IF frequency i.e. they say that we shouldnot take carrier frequency to be 2.4GHz but instead should take it to be 380MHz as in superhet our working frequency is 380MHz
and other guys disagree with it
can u help me with it as i myself m confused ...i believe it should be 2.4GHz but if m wrong please elaborate how

 

[rectifier]

any rf expert here

You can modulate the signal using IF if your superhet is used only for a single carrier. But it will be a problem if there are more than 1 carriers. In that case, you would need frequency converter to downconvert the RF carrier to IF.

 

[Darren_pan]

any rf expert here

I suggest you should read one simple book or article which introduce the concept of RF,No one can explain the RF clearly in here...you know the field is complicated as your field.. you need spend a little on it.

 

[bcl]

Re: any rf expert here

If the receiver front end is designed to receive 2.4 GHz, the the transmitter carrier frequency better be 2.4GHz. Whether you get to 2.4GHz via an IF or direct modulation is a design trade off. Having an IF requires more parts, e.g., mixer, filters, etc., but the LO leakage issue will not be nearly as tough as direct conversion to 2.4 GHz.