Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Question about RF trace width on a PCB

Status
Not open for further replies.

wccheng

Full Member level 5
Joined
May 16, 2004
Messages
287
Helped
1
Reputation
2
Reaction score
0
Trophy points
1,296
Activity points
2,710
Dear all,

I have question about the RF trace width on the PCB. I hope anyone could give me a help. Thanks first :)

For example, I have calculated the width of the trace based on the equation. I found that the width = 1mm, then the trace is 50ohms impedance. However, there are impossible to make the RF trace as same width as the whole length becaues the trace need to connect some SMD components and the chip pins. As you know this pin are very small in size. So, I need to be narrow the trace to connect it. Then, how could I know the effect of the narrow part? What is the varation from 50ohms?

Does any rule of thumb to route this RF trace width on the PCB? Is I don't need to care the width of the trace when the length of the trace is shorter than (lamda/20)?

I hope anyone could help me.

Thanks

wccheng
 

boy

Advanced Member level 1
Joined
Sep 30, 2002
Messages
481
Helped
96
Reputation
192
Reaction score
55
Trophy points
1,308
Location
Thailand
Activity points
3,963
pcb trace width

So you gonna use that with you murata switch? the step impedence will act as a low pass filter. you can use a CAD tool to see the effect by connecting two diferrent width transmission lines and simulating it.
 

wccheng

Full Member level 5
Joined
May 16, 2004
Messages
287
Helped
1
Reputation
2
Reaction score
0
Trophy points
1,296
Activity points
2,710
rf trace width

Dear,

Any simulator could simulate it? ADS or HFSS?

thanks
wccheng
 

boy

Advanced Member level 1
Joined
Sep 30, 2002
Messages
481
Helped
96
Reputation
192
Reaction score
55
Trophy points
1,308
Location
Thailand
Activity points
3,963
pcb trace width rule

ADS would do the job. There are two ways in ADS: using the empirical model (fast) orf momentun. HFSS is a fullwave simulator. you will get a better result but it will take longer time to simulate.
 

jarod5724

Junior Member level 1
Joined
Nov 17, 2005
Messages
16
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,394
rf pcb trace to rf pin

ads has a particular tool ""to calculate the width and electrical degree about the certain impedance microstrip , use it
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top