RF Microstrip PCB Design with a Normal Circuit Simulator: A Wilkinson Combiner

RF Microstrip PCB Design with a Normal Circuit Simulator: A Wilkinson Combiner

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Other parts in this series:

In this video, I'll show you how to design and build a two-stage Wilkinson power splitter/combiner. A power combiner is an incredibly useful building block in RF electronics. I’ll explain the basic theory behind it (which involves quarter-wave transformers) and demonstrate how to design and simulate such a circuit. Additionally, I’ll guide you through creating the RF PCB layout and share the measurement results using a NanoVNA. The results are impressive, especially considering that I’m using standard FR4 material and a very simple design process which does not require expensive EM simulators like HFSS or Microwave Studio.

00:00 Introduction
00:23 Power combiner fundamentals
01:05 Different ways to try and build one
03:09 Quarter Wave Transformers explained
04:53 Info about my new course
06:06 Quarter Wave Transformers in a Spice like simulator
09:08 Quarter Wave Transformer Calculations
11:03 Quarter Wave Transformer Measurement Demonstration
12:45 Return Loss in a Simulator
13:37 How to fix Matching and Isolation in a Wilkinson Combiner
15:16 How to simulate all parameters of a Wilkinson Combiner
16:09 How to design a Dual Stage Wilkinson Combiner
17:35 How to get the parameters for the PCB Layout
18:21 Dual Stage Wilkinson Combiner Layout
18:43 Measurement Setup
19:16 Dual Stage Wilkinson Measurement Results
19:41 Comparison of Measurements and Ideal Simulation
20:26 Achieved Specifications compared to Ideal Simulation
20:56 Hope you enjoyed it

[t]

Time flies when you're having fun. That was a complicated video that really challenged me. Thanks!

[jeremiahrex]

I agree I have good taste and you make good videos! Smith charts have confused me since university. I need to watch that R&S video just to conquer them finally!

[VoiceofNH]

Really, really excellent presentation. Thank you!

[IZXAF]

When there is RF stuff I have all the attention that you want, really nice done!

[Kotbenek]

Great video, thanks for explaining RF topics in the way that is easy to grasp!

[CristianoFénix-zb]

I have no idea what you’re talking about. But am interested in circuits. Excellent stuff.

[tommihommi]

QUCS (or qucs Studio which adds some nice features) should be much more suited for this job
I haven't used it much myself, but for one, it comes with smith charts built-in...

[gerriegoeree]

Greetings from your former collegue!! Following you now and then in your video's, enjoy them very much.

Gerrie

[SaltyPuglord]

Thanks for this video, great stuff! I posted it over at Reddit, on the RFElectronics subreddit. Hope I can drive some more views your way - you've certainly earned them with your amazing content!

[andresmartinezmera]

Great video! IMHO, Qucs-S is best suited for this. It also comes with a power combining design tool.

[perenis-zr]

Thanks, that was really informative. You mentioned ε is a bit uncontrolled in commercial FR4; is it possible to work back from your results to find the actual average value for an improved iteration? Presumably your looped traces give a better average value than a straight trace, due to the weave of the PCB.

[aquahoodjd]

I hit you up right when you started on LinkedIn saying you were a great so I said I'm receiving a signal of one pulse per second or have gone ahead and put it through temperature controlled or ocxo module and have a 10 megahertz signal and I want to divide that up between 4:00 SMA outs! I I'm already using a really good pulse per second and a microcontroller to create my own network time so I would like to sync all of my RF devices with the same 10 MHz clock.

[Sergei_Goncharov]

A transformer with ferrite core working at frequencies up to 3GHz looks like a miracle. I can't believe it's true, the loss in the core will be too large. Once I needed to design a galvanic isolation for TV line with low loss and working frequencies up to 900MHz and I didn't find a proper ferrite transformer.

[marcfruchtman]

Great info. This video gives me some cool ideas for the kinds of tools that are helpful in electronics. I really appreciate the exceptional knowledge that you are sharing.
As far as attention span, 20 mins is a good soft "max" for a video. Of course, it does depend on the content.
Do you have tools that allow you to show "viewing time" on a individual viewer basis or perhaps "average viewer" basis?

[susanrobins]

Good Stuff, and yes I have a attention span.

[glasslinger]

Let's get to the more fun stuff. 20 to 40 ghz. The 2 ghz stuff is like working with audio! What do you do when the smith charts don't work any more!

[Jeroen]

Have you ever tried Sonnet Lite? It's a free RF electromagnetic planar structure simulator.

[rjordans]

Python can do schmitt charts quite niceliy with the scikit-rf package

[aquahoodjd]

I'm assuming that a 10 MHz quarter wavelength it's going to be a pretty long transmission line

[ats]

I'm a little confused why you went through a long procedure at 9:30 for calculating the impedance of the quarter wavelength stub rather than just taking the geometric mean of 50 and 100 ohms. Anyway, very nice video! Thanks.