What are the RF designing rules?

[luckyali]

Hallo every one.
Since I am totally new to PCB designing. and have very little knowledge about RF designing.
I would like to know what are the important technical parameters or RF designing Rules that should be studied before stepping into designing.
I mean to say what things should be considered. e.g if some one say 1st keep in mind the selection of material, types of connectors or so so.

Any thing else please help me out in this field.
I hope I cleared my Question

 

[srizbf]

Re: new to PCB designing

the pcb material is to be selected for rf use.

not all is suited for rf use , like , the lowend , phenolic types.
glass epoxy and others are to be considered.

for rf , fore most thing in pcb track is the shortest track length possible.

this again depends on your frequency of operation.

but as a general rule shorter the better.

adequate shielding must be provided in pcbs for rf.

probaly if your freq is known , then some more advice may come.

 

[luckyali]

Re: new to PCB designing

actually i will be doing my university project and we will deal with 20 Ghz, so we want to design a Frequency Up down converter from 4 Ghz to 20 Ghz. the component IC's have been ordered now we have to work in Eagle CAD for designing all the schematics and layout of this board.
(in our university we have ROGERs but still we have to find better for higher frequencies)
so i have few things my self in mind,
1st of all select the material for 20 Ghz,
2. The dimension of the board
3. Thickness of the board
4. Width of traces
5. Impedance of lines

I would like to know about different approaches to calculate these things or anything else which should be considered ???

 

[cks3976]

Re: new to PCB designing

.....
(in our university we have ROGERs but still we have to find better for higher frequencies)
so i have few things my self in mind,
1st of all select the material for 20 Ghz,
2. The dimension of the board
3. Thickness of the board
4. Width of traces
5. Impedance of lines

I would like to know about different approaches to calculate these things or anything else which should be considered ???

1. Rogers is a good material for RF applications. Its one of the expensive dielectric materials available..
2. Dimension of the Card depends on the number of components you will be placing on the Card, traces and other mechanical fixtures. Its purely driven by your requirement. There is no hardened rule for that.
3. Thickness of the Card depends on what thickness can your fabricator manufacture. It depends on thickness of laminates you will be using & impedance control requirements of your design- again there is no formula for this.
4. Width of trace depends on the target impedance of the trace. Check Impedance Calculators - Mantaro Product Development Services for impedance calculators. There are several other good web resources.
5. ANSWERED

Hope this helps