What an excellent presentation... Really clear and tells the viewer how he things through the design. Why could my college professors not be this clear???? Very good....
You have a easy way to speack about complex issues... Even my self that dont speack english very well could understand your ideas... (ofcourse i repeated the videos a lot of times.. lol) Congratulatios guy!
Sebastian, Very good explanation. I have one question for you. I was reading one of the text books and could not understand how the S-parameter matrix elements are obtained for these power dividers. So, could you please make a video or even give an explanation about the S-parameter matrix explanation for resistive and Wilkinson power divider ? Regards, Vinay Hegde
Hi, Excellent video. I learned something here! Although I was confused with the tear down portion of the video. Why were you surprised to find 2 inductors in the splitter? Your white board diagram did show 2 pi networks each with an inductor. Thanks
Hi Sebastian, I've just noticed that your back to making videos and I have just watched your white board tutorials on the Wilkinson splitters again. I found that watching them again 6-9 months later that things very quickly fell into place, enough that I picked up on some important points that I had missed first time around. (Probably concentrating on the maths too much rather than the concepts) Your comments on the wave travel time to achieve the 180 degree phase shift really nailed for me one more aspect of transmission lines which I'm very shaky on at best. Any time you feel that you wish to expand on the "aside" of using and intermediate frequency and a second 1/4 wave transmission line to increase the bandwidth, I for one will be very happy to watch and learn. Thanks very much for the lessons... Rubin
+Rubin Jeffs Thanks for your comment Rubin. I will try to continue to work through microwave and RF "basics" such as this. So I definitely will expand on some greater details and different types. I absolutely want to make a video in which I'll walk my audience through a practical design of a stripline splitter / combiner.
Hi KF5OBS, I think the signals traveling total lamda/2 distance is actually 360 degree not 180 degree. So the signals from port2 to port3 are in in phase not out of phase. as wilkinson dividers are equal magnitude and equal phase on the output ports. As lamda/2 is equal to 360 degree as because in smith chart it accounts both transmitted and reflected wave which is total 360 degree. Please shed some light on it. Thanks.
No, it's 180 degrees as I correctly said in the video. 1/4 lambda being 90 degrees in terms of transmission. So from the star-point to port 2 or 3 it's a phase coherent output. But From port 2 to 3 or 3 to 2 it's 180 degrees.
Sebastian, Good teaching! Question: I ran an ADS model for a 2way Wilkinson combiner with 0dBm 0deg on each leg and output was +3dBm. Can you explain why when I either open or short one of the combiner inputs my output power goes to -3dBm? Also, is there a similar equation for an N way combiner as there is for an N-way splitter, that is, like dB=10log(1/N) ? thanks
I am looking into to connect my HF antenna to my transceiver and my SDR (the function of padadapter). I will use some relay (with enough isolation) to disconnect the SDR from the transceiver when transmitting. As when receiving both receivers needs to be combined maybe I can use this circuit. One thing I don't know is will it (or better how much) degrade the input signal (that insertion loss) from the antenna?
A Wilkinson is not very broadband. Your project sounds like you need to split a large frequency range, correct? In that case, the Wilkinson divider would not be a good design choice.
@BalticLab Thanks. I enjoyed your lesson. I have realized the relatief constraint, as you work with a resonant circuit. Most of the time I use the 20m band though. But yes, not ideal solution indeed. Before this I was thinking about a simple source follower with an hf fet, but I need to figure it out, as I don't want to degrade the signal from the antenna to this SDR receiver.... Any other ideas?
Is there a way to use the traces to minimize parasitics of the resistor? literally assuming 0.5pF parallel capacitance and it reduces my isolation from 20dB to 11dB. I'm operating in the S band (2-4GHz), and my resistor is resonating at 2.5GHz. Based off the theory... I could select a resistor value (assuming capacitance is the same) so that I get 2*Zo impedance at my desired frequency. of course this would result in a narrow band wilkinson, but my application is also narrow band
You could compensate for that, but if your SRF is that close to your operating frequency, use different components... Stack different values if necessary.
The math is still a complete mystery some examples would be nice 108mhz is the goal... I would like to upgrade all of my transmitters to Wilkinson combiners but I cannot figure out the math and I'm currently using resistive combiners...
Hey Terry, I made another video showing the math for a 2-way equal split Wilkinson. Check it out: ua-cam.com/video/3IAVJ4gVunE/v-deo.html Also note the text article in the video description.
Hi! Thanks for the Wilkinson article. I have a couple of questions. First, suppose I need much narrower bandwidth...say...the FM Broadcast Band. 88-108 MHz. I need really good port isolation above 150 MHz (40 dB). Can I achieve that with an 8 port design? How do I calculate the value for C and L? Thanks!
Lyn Williams I might be wrong, but I believe you'll get isolation between ports only within the the bandwidth it's designed for (FM band).. If you want isolation at the margins, you'll need to adjust the resistor value...But changing the resistor value, will change impedance and VSWR.....
I wish someone would explain this with resistors every antenna uses a 50ohm load so when you try to throw all the mumbo jumbo in it just doesn't make any sense or just say what is needed to make one
Hey David! Unfortunately, we're not dealing with resistance here but with an impedance. Your antenna and the coax cable also have a 50 Ohm impedance. But their resistance will be a completely different value, usually. I posted another video where an actual example is calculated and built: ua-cam.com/video/3IAVJ4gVunE/v-deo.html If you prefer to read, check out the corresponding article on my blog: baltic-lab.com/2014/09/lumped-element-wilkinson-splitter-combiner-design/
Hi, I'm trying to matching or coupling impedance between the transmission line and an antenna in an AM transmission, how I can use the Wilkinson Bridge to achieve this? Can you help me?
![Building a Wilkinson Splitter/Combiner [RF Circuit Design]](http://i.ytimg.com/vi/3IAVJ4gVunE/mqdefault.jpg)
![Building a Wilkinson Splitter/Combiner [RF Circuit Design]](/img/tr.png)
![Resistive Splitters and Combiners [RF Circuit Design]](/img/n.gif)
What an excellent presentation... Really clear and tells the viewer how he things through the design. Why could my college professors not be this clear???? Very good....
Easy to follow with practical equipment application. Kudos
You have a easy way to speack about complex issues... Even my self that dont speack english very well could understand your ideas... (ofcourse i repeated the videos a lot of times.. lol)
Congratulatios guy!
+Marcos Norte Thanks so much for your feedback!
Very clear and intuitive explanation. Thank you very much
LamarSweeney Glad you liked it!
Sebastian,
Very good explanation.
I have one question for you. I was reading one of the text books and could not understand how the S-parameter matrix elements are obtained for these power dividers. So, could you please make a video or even give an explanation about the S-parameter matrix explanation for resistive and Wilkinson power divider ?
Regards,
Vinay Hegde
Grate Video, and no complains about the Drawings.
Glad you like them!
Hi,
Excellent video. I learned something here!
Although I was confused with the tear down portion of the video. Why were you surprised to find 2 inductors in the splitter? Your white board diagram did show 2 pi networks each with an inductor.
Thanks
Many thanks, did most of my project using this
Awesome, glad I could help!
Hi Sebastian,
I've just noticed that your back to making videos and I have just
watched your white board tutorials on the Wilkinson splitters again.
I found that watching them again 6-9 months later that things
very quickly fell into place, enough that I picked up on some
important points that I had missed first time around.
(Probably concentrating on the maths too much rather than the
concepts)
Your comments on the wave travel time to achieve the
180 degree phase shift really nailed for me one more aspect
of transmission lines which I'm very shaky on at best.
Any time you feel that you wish to expand on the
"aside" of using and intermediate frequency and a second 1/4
wave transmission line to increase the bandwidth, I for one will
be very happy to watch and learn.
Thanks very much for the lessons... Rubin
+Rubin Jeffs Thanks for your comment Rubin. I will try to continue to work through microwave and RF "basics" such as this. So I definitely will expand on some greater details and different types. I absolutely want to make a video in which I'll walk my audience through a practical design of a stripline splitter / combiner.
Hi KF5OBS, I think the signals traveling total lamda/2 distance is actually 360 degree not 180 degree. So the signals from port2 to port3 are in in phase not out of phase. as wilkinson dividers are equal magnitude and equal phase on the output ports. As lamda/2 is equal to 360 degree as because in smith chart it accounts both transmitted and reflected wave which is total 360 degree. Please shed some light on it. Thanks.
No, it's 180 degrees as I correctly said in the video. 1/4 lambda being 90 degrees in terms of transmission. So from the star-point to port 2 or 3 it's a phase coherent output. But From port 2 to 3 or 3 to 2 it's 180 degrees.
Sebastian, Good teaching! Question: I ran an ADS model for a 2way Wilkinson combiner with 0dBm 0deg on each leg and output was +3dBm. Can you explain why when I either open or short one of the combiner inputs my output power goes to -3dBm? Also, is there a similar equation for an N way combiner as there is for an N-way splitter, that is, like dB=10log(1/N) ? thanks
People with fabulous equipment make me feel like disappearing!
Thanks for that. I learned something here.
What is a Tyco Ma-Com H-8-4 2-2000 MHz? Presumably too wide in bandwidth to be Wilkinson.
this video is really rad dude thank you
Late to the show but of course, enjoyed it just the same. Very interesting. My brain is playing catchup. Thank you 👍😁 SUBBED! ❤
9:24 ''Once again, you can clearly see why I had an F in all arts related classes''... Lol
I am looking into to connect my HF antenna to my transceiver and my SDR (the function of padadapter). I will use some relay (with enough isolation) to disconnect the SDR from the transceiver when transmitting. As when receiving both receivers needs to be combined maybe I can use this circuit. One thing I don't know is will it (or better how much) degrade the input signal (that insertion loss) from the antenna?
A Wilkinson is not very broadband. Your project sounds like you need to split a large frequency range, correct? In that case, the Wilkinson divider would not be a good design choice.
@BalticLab Thanks. I enjoyed your lesson. I have realized the relatief constraint, as you work with a resonant circuit. Most of the time I use the 20m band though. But yes, not ideal solution indeed. Before this I was thinking about a simple source follower with an hf fet, but I need to figure it out, as I don't want to degrade the signal from the antenna to this SDR receiver.... Any other ideas?
Very helpful videos. Keep it up.
Is there a way to use the traces to minimize parasitics of the resistor? literally assuming 0.5pF parallel capacitance and it reduces my isolation from 20dB to 11dB. I'm operating in the S band (2-4GHz), and my resistor is resonating at 2.5GHz.
Based off the theory... I could select a resistor value (assuming capacitance is the same) so that I get 2*Zo impedance at my desired frequency. of course this would result in a narrow band wilkinson, but my application is also narrow band
You could compensate for that, but if your SRF is that close to your operating frequency, use different components... Stack different values if necessary.
The math is still a complete mystery some examples would be nice
108mhz is the goal...
I would like to upgrade all of my transmitters to Wilkinson combiners but I cannot figure out the math and I'm currently using resistive combiners...
Hey Terry, I made another video showing the math for a 2-way equal split Wilkinson. Check it out: ua-cam.com/video/3IAVJ4gVunE/v-deo.html
Also note the text article in the video description.
Hi! Thanks for the Wilkinson article. I have a couple of questions. First, suppose I need much narrower bandwidth...say...the FM Broadcast Band. 88-108 MHz. I need really good port isolation above 150 MHz (40 dB). Can I achieve that with an 8 port design? How do I calculate the value for C and L? Thanks!
Lyn Williams I might be wrong, but I believe you'll get isolation between ports only within the the bandwidth it's designed for (FM band).. If you want isolation at the margins, you'll need to adjust the resistor value...But changing the resistor value, will change impedance and VSWR.....
11:50 I would never think that those two capacitors are parallel
Very informative. Great teaching skills, thank you! 73 de YO6SSW
do you know something about power divider topology? 0-180° fot
Thank you
I wish someone would explain this with resistors every antenna uses a 50ohm load so when you try to throw all the mumbo jumbo in it just doesn't make any sense or just say what is needed to make one
Hey David! Unfortunately, we're not dealing with resistance here but with an impedance. Your antenna and the coax cable also have a 50 Ohm impedance. But their resistance will be a completely different value, usually. I posted another video where an actual example is calculated and built: ua-cam.com/video/3IAVJ4gVunE/v-deo.html
If you prefer to read, check out the corresponding article on my blog: baltic-lab.com/2014/09/lumped-element-wilkinson-splitter-combiner-design/
Hi, I'm trying to matching or coupling impedance between the transmission line and an antenna in an AM transmission, how I can use the Wilkinson Bridge to achieve this?
Can you help me?
how to design radial power combiner on IE3D software. from where i can get thoses files. need some help for my project.
thanks a lot
what happens is one of the input port is left unconnected or unterminated? How much signal will reflect back?
You just kind of don't... That's what my professor told us at least.
Life saver
thank you