How to Design a PCB with an Antenna

[@PredictableDesigns]

Prevent mistakes by downloading your FREE DESIGN REVIEW CHECKLISTS for the schematic circuit, PCB layout, and enclosure 3D model design: predictabledesigns.com/design-review-checklists-youtube/ And get your other free guides: Ultimate Guide - How to Develop and Prototype a New Electronic Hardware Product in 2023: predictabledesigns.com/guide From Prototype to Production with the ESP32: predictabledesigns.com/esp32 From Arduino Prototype to Mass Production: predictabledesigns.com/from-arduino-youtube/ From Raspberry Pi Prototype to Mass Production: predictabledesigns.com/rpi Want my personal help on your project? If so, check out my Hardware Academy program: predictabledesigns.com/Academy

[@TheMoschettis]

RF is hard! Where you place your Antenna is just as important as how well its matched. The product you place the antenna in can detune the antenna and kill your performance. Then you quickly end up in a 3D RF Modeling software and keep people like me employed :)

[@PredictableDesigns]

RF is definitely hard, even for many electrical engineers. RF is very specialized indeed.

[@johnnyreb280]

Absolutely....RF antenna design is complex because of several factors, impedance matching to minimize signal reflection, achieving desired radiation patterns, and ensuring wide bandwidth without losing performance. Also, we must account for polarization, size constraints, and material properties all the while maintaining performance across varying environmental conditions. Interference management and isolation between multiple antennas or electronic devices further add to the complexity. I can attest that mastery of electromagnetic theory and practical engineering skills are totally essential to navigate these intricate issues effectively... Lots of my designs have failed but, those that prove themselves exceptional performance make up for the designs that fall flat.

[@Karlemilstorm]

I was wondering about the vias you call stitching vias at 12:50. I understand that they are giving a low impedance connection to the ground plane. But aren't their purpose also to shield the remaining circuit from the electric fields from the antenna - and vice versa?

[@PredictableDesigns]

Yes, correct, and I probably should have said that in the video. Thanks for the comment!

[@robertochostakovis]

One thing I would do is set keep off of couperpour at least 15 mils, mainly on phy filter. You can have miss soldering leaving the gnd pads strong tied to couperpour. Excelent explation about pcb boards with RF!

[@PredictableDesigns]

Thank you!

[@zikoraa]

Thanks John, this was very informative. I will go for more!

[@PredictableDesigns]

Great to hear, thank you.

[@digitalradiohacker]

The next problem is that you have to take into account how the product will be used. If the product is sat on a wooden desk, clear of other objects, you can characterise the radio parts in an accurate manner. If the product is handheld, or the sort of thing that is carried in a pocket, or all of the above (desk/hand/pocket), then you will not be able to put the perfect system toghether because proximity to "other things" will affect impedence, efficiency and radiation pattern. It might be worth noting that if the PCB traces are very short compared to the wavelength, then it makes very little difference how traces are spaced etc. This gets less and less true as the the wavelength gets shorter as the frequency gets higher. A product that works at 433MHz has a wavelength of about 70cm so it is less critical. A product that works at 2.4GHz has a wavelength of about 12cm and trace spacing etc become very imortant. You can self test antenna efficiency by making a cheap field strength meter: www.utaharc.org/rptr/wdr_fsm1.html Analogue meter with something like 100uA @ full scale: www.rapidonline.com/rvfm-model-sd-670-fsd-dc-100-a-moving-coil-meter-range-0-100-a-48-0305 A couple of diodes with low forward voltage as a rectifier. A capacitor to smooth the output of the rectifier. A resistor to discharge the capacitor (make it a trim-pot) A higher deflection on the meter = better overall efficiency, and this also takes into account how it is used (hand/desk/pocket).

[@PredictableDesigns]

Wow, what a great post! Thanks so much for sharing these additional tips!

[@nabilel-sheikh9747]

i have a question please , if i have a PCB external antenna for 4G usage on my board , where is the best placement for it ? above the board , beside the board , perpendicular to the board !

[@panomsuk397]

Thanks John, This video is great that give me an idea for design of GHz range on PCB. I believe it is so complicate compared to my past experience only for external antenna from 40 to 2 meters for amateur radio.

[@PredictableDesigns]

Glad to hear that Panom! Thanks for the comment.

[@alexi5473]

I have a similar design, but I use an ANT3216A063R2400A as an antenna. When I activate BLE I hear "rattling" noises. Is this due to a lack of power supply or is it due to incorrect impedance?

[@caiodutra9635]

Very helpful man, that is a really good work. Thanks a lot

[@PredictableDesigns]

You are most welcome! Thanks.

[@anlpereira]

Hi, great video. Can you make this video for an ESP32-S3 board with MIFA? I’m saw in the Design Guidelines that the output impedance of this IC is 35ohm+0j. So, how to calculate the CLC matching circuit if the output impedance of the ESP32 ? I have seen a few online calculators. Another question is, is it possible to design a 35ohm PCB Antenna and don't use any macthing component? Thank you very much.

[@PredictableDesigns]

Thanks for the suggestion. I've not been doing much antenna design lately but I'll consider it. I'd suggest checking out this video: kzbin.info/www/bejne/r6m4kH6tZ8mYZposi=wSQZ3s4EAoFc_35n

[@husamettinglocs]

thank you very much for nice, clean and straightforward explanations. i very much like your videos. immediately subscribed. thx a lot !

[@PredictableDesigns]

Awesome, thank you!

[@rebecachan3971]

You mentioned third party services that will analyze the board and give you the values for the CLC circuit for max power transfer. Can you give me some names of such services ? or if I do a google search, what would I search for ?

[@PredictableDesigns]

Hi Rebeca, thanks for watching and for your question. Some of the chip antenna manufacturers provide tuning services. You can also google "pcb antenna tuning service" and you will find several companies offering this service.

[@acamelbeke6852]

Hi nice video! I learned a lot! But I'm still wondering how to design the CLC network (values of the C1,C2 and L1) Can you explain this to me?

[@PredictableDesigns]

Great, glad to hear that! Those values are usually determined as part of the tuning process. I've always outsourced the tuning to a 3rd party lab.

[@remy-]

Nice movie! One question: I see a lot of islands, special reason for that, or in the middle of designing?

[@PredictableDesigns]

Thank you! Yes, those unconnected ground plane islands should be removed in the final design. These unconnected islands act like little capacitors. That being said, their impact will be insignificant for a low-speed design such as this one as long as they are not near the antenna feedline. There is an option in DipTrace for copper pours where you can set it so these islands are not created. I obviously did not have that set correctly when I set up this copper pour. This PCB design was from an older design I worked on years ago and I'm not sure of the status, and my intention was just to use it for demonstrating the feedline layout.

[@remy-]

@@PredictableDesigns it’s a great movie!

[@electroroomi]

So, if I select 2 layer PCB, I must use the board with thickness 0.6mm to 1mm (considering coplanar WG). Else the trace width will be very large.

[@PredictableDesigns]

Yes, correct. If the dielectric material between the two layers is thicker, then you require a wider feed line to achieve the 50 ohm impedance.

[@RixtronixLAB]

Nice video, well done, thanks for sharing it with us :)

[@PredictableDesigns]

Thanks for watching!

[@abdifatahaden4761]

I didn't completely understand what you said. Will you or won't you need to get it professionally tuned if you use AppCAD? If it's about the ground plane can you not just simulate the impedance inclusive of the ground plane as well?

[@TheMoschettis]

This is what makes RF so difficult and confusing for people who arent educated on it. There is not going to be a yes or no answer, it is all use depenedent. A lot of times simple matching with a CPWG will work fine and other times where it wont work at all. Like all engineering their is only one way to find out, do it. Their is a knowledge of RF and how it works that can help you make good decisions when designing a system. This will allow you to simplify the process and mostly guarantee success. This is most likely where "Predicatable Designs" lives. They know enough to not make critical mistakes in the early layout process allowing them to prevent time/cost sucking re designs. They dont need to be experts in probably 75% of their work so outsourcing the other 25% isnt a big deal.

[@abdifatahaden4761]

@@TheMoschettis I want to avoid having to outsource if I don't need to. What is the best way to simulate the effects of the enclosure and the shape of the board and ground plane and components? I've seen ANSYS HFSS recommended but are there other options for 3D RF modeling? What is your go to?

[@TheMoschettis]

@@abdifatahaden4761 I do this for my job so I use ANSYS HFSS or CST. Not sure what is a cheaper version of those that can get you to where you want to be. I will say that if youve never used an RF Simulation software before getting set up is going to be incredibly difficult.

[@abdifatahaden4761]

@@TheMoschettis How accurate are the simulations, if you're good can you usually have it be one and done?

[@TheMoschettis]

@@abdifatahaden4761 assuming you need to us a 3D modeler its going to be incredibly complex. Best thing you can do is design a 2D version and try and manually tune it until it works. Might get you by with a prototype for now. You dont want to end up in a 3D modeler. Doing your matching network in ADS or Microwave studio should be the best fix to your problem. You can even design your matching network by hand or using a smith chart if you dont have access to any design software.

[@bhyregowdagr5808]

This is which antenna active or passive

[@PredictableDesigns]

Passive

[@andyqu3395]

谢谢

[@Rayrockny]

Anyone know a good low voltage bluetooth module with antenna that's already certified, for a good price?

[@PredictableDesigns]

I like Nordic based modules from Fanstel.

[@Rayrockny]

@@PredictableDesigns wow I just purchased the BC805M module. I already have my prototype working with an HC-05 but that's no good. I wish I knew about your channel earlier, I would have started with something FCC certified, another learning lesson I guess. I'm going to test the Fenstel chip with my design if it works I'm going to redraw my schematic to incorporate it. Thank for the help again, cheers.

[@hugopristauz3620]

helpful 🙂!

[@dmytromykhailiuta]

DopTrace, its cool ^)