RF front end in system level

[bzaki]

Hello,

I want to design RF front end in system level.

Can anyone please tell me what do I need from books/papers/software to understand terms such as IP3,NF , dynamic range, image rejection and to design the RF front end in system level using simple models for mixers, amplifiers and filters?

Thanks in advance.

Regards,
Bassem Zaki

 

[cmosbjt]

Please read books from Razavi and Tomas Lee. They can be downloaded from this forum.

 

[bzaki]

I took a look in all these books but still didn't find a detailed explanation for IP3 or NF

I also need to know how to convert the standard specifications into circuit specs for mixers, amps and filters

 

[biff44]

You need to do the following steps:
1) determine the transmit and receive requirements for your system as a black box
2) Choose appropriate components for the Tx and Rx components
3) Plug the component performance values into a cascade analysis program. This will compute, for example, the Rx total noise figure from you stated LNA NF and gain, mixer NF and loss, IF amp NF and gain, etc. It will compute cascaded gain, NF, IP3, etc.
4) If the system performance is poor, look over the cascade analysis spread sheet, replace the worst component or two with a better one, and run the analysis again.
5) After you are close, try varying things, like the receiver gain due to AGC circuits, etc.

Good luck. It is 1/3 art, 2/3 calculations.

 

[RFDave]

Hi:

Biff44 has pretty much nailed the process. Step 2 could be expanded a bit. You need to make an assumption about the Receiver topology that you are targeting. If you assume that you are targeting a dual-conversion superhet receiver, then you will get different block level specifications than if you target a direct conversion receiver topology.

Step 1 can be very tedious. If you are targeting something like TD-SCDMA or CDMA, the specification's that you need to pull out for an accurate black box analysis are typically scattered throughout the spec, and so you need to make sure you go through the entire spec a couple of times to make sure you catch everything.

You might want to look at the Vizmuller RF Design Guide book it's got a pretty clear explanation of all of this stuff.


Dave

 

[wpsch]

Try the book "Microwave and RF Design of wireless system", by Pozar. It describes both NF and IP3 for a system.

 

[hcseu]

<<Microwave and RF Design of wireless system>>
this book is easy for understanding

 

[qiang]

first ,I think your question is not how to design the RF front end,but the base knowlege of the system.you should have more base kowlege of this subject.you can find some book in the UESTC .

 

[DonJ]

Hi

With the basic knowledge at hand, you get a pretty good understanding and an overall view by (even) using an Excel sheet.

For an integrated solution, i.e. not 50 ohms interface, you should use the equations for NF and IIP3 according to Razavi's book (1/2-factor). The difference between your simulated and estimated results might be within 0.3dB for NF.

All the best

 

[dsjomo]

Try the book -

"CMOS CELLULAR RECEIVER FRONT-ENDS - from specification to realization" by J. Janssens & M. Steyaert.

I think this is want you want.

 

[spweda]

First you need look at the system specification for your system design. For CDMA, look at the IS98 minum performance specification for mobile phone, For GSM, look at the ETSI soument. From the minimum perforamnce, decide the overall noise figure (NF). Patition the NF into different stages (LNA, Mixer, Analog filter, VGA, A/D). You need a simple excel program to look at the NF partition. You need some experiences to make the partition.

 

[ChaoFan]

first ,I think your question is not how to design the RF front end,but the base knowlege of the system.you should have more base kowlege of this subject.you can find some book in the UESTC .

Can you tell me in detail what UESTC is ? And how to find the books?

Added after 3 minutes:

Try the book -

"CMOS CELLULAR RECEIVER FRONT-ENDS - from specification to realization" by J. Janssens & M. Steyaert.

I think this is want you want.

I need the book you said too, Could you tell where I can downlaod it for free?
Thank you in advance.

 

[bzaki]

You can find this book on this forum here is the link:

 

[dr_em]

Try the book "Microwave and RF Design of wireless system", by Pozar. It describes both NF and IP3 for a system.

Pozar's "Microwave Engineering" is also another good book.