ESP32 + PCB Antenna Hardware Design Tutorial - Phil's Lab #90
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- เผยแพร่เมื่อ 18 พ.ค. 2024
- How to design custom hardware using ESP32 MCUs (ESP32-C3, NOT pre-made modules!) and PCB antennas (inverted F, in this case). PCBs by PCBWay www.pcbway.com
Showing examples and real, working hardware (WiFi scan test), a full schematic walkthrough, and a PCB design walkthrough. Final test using Arduino IDE & ESP32 expansion.
Many more ESP32 firmware & hardware tutorial videos to come!
[SUPPORT]
Free trial of Altium Designer: www.altium.com/yt/philslab
PCBs manufactured and assembled by PCBWay: www.pcbway.com
Patreon: / phils94
Mixed-signal hardware design course: phils-lab-shop.fedevel.education
Advanced Hardware Design Course Survey
forms.gle/X4jwvtZeJ1jTXh7r9
[GIT]
github.com/pms67/ESP32-USB-Do...
[LINKS]
Instagram: / philslabyt
ESP32 Hardware Design Guidelines: www.espressif.com/sites/defau...
ESP32-C3 Datasheet: www.espressif.com/sites/defau...
TI PCB Antenna Application Note: www.ti.com/lit/an/swra117d/sw...
[TIMESTAMPS]
00:00 Introduction
00:29 Altium Designer Free Trial
00:49 PCBWay
01:19 ESP32-C3 and Hardware Overview
04:28 ESP32 Hardware Design Guidelines
06:14 Schematic - ESP32-C3 Power Pins
07:26 Schematic - Crystal
08:50 Schematic - Chip Enabled (Reset)
09:16 Schematic - SPI FLASH
10:21 Schematic - USB and Power
12:29 Schematic - UART, Sensor
13:26 Schematic - Bootmode Select
14:10 Schematic - PCB Antenna
17:43 Schematic - RF Matching Network
22:15 PCB - Overview & Stack-Up
23:47 PCB - Controlled Impedance
24:10 PCB - General Guidelines, Decoupling
25:54 PCB - Antenna and Matching Network
29:22 WiFi Test (Arduino IDE)
33:37 Outro - วิทยาศาสตร์และเทคโนโลยี
![ใจดำกับฉันก่อน - วงทัพห้า [Official MV]](http://i.ytimg.com/vi/I48wa4qurAU/mqdefault.jpg)
New ESP32 hardware design tutorial coming soon!
Some comments: 1) I'd strongly recommend using off-the-shelf, pre-certified modules unless you have a very good reason not to. This video is more of a 'fun demonstration', rather than something that should be used practically. 2) Although I haven't had issues so far, the chip-enable cap (C19) value should be increased for reliability (as otherwise the default bootmode and chip enable come up at the same time on power on). 3) The antenna matching network and antenna itself will need to be tuned on the real PCB. These are just ballpark values. 4) There is a variant of the C3 (C3FN4) which contains built-in 4MB flash. Meaning you don't need external flash - however, these SPI pins on the C3FN4 cannot be used. Additionally, I believe the C3FN4 is NRND.
Thanks so much for putting this video back up Phil. Me and the rest of the beginner ESP32 designer guys really appreciate it. Why'd you put it back up btw? Also, for any of you guys reading this, you can just use the ESP32-C3FH4X, ESP8685H4, or upcoming ESP8686 for your new designs as they are either active or about to be released.
Once again, Phil has come to the rescue by making a video of exactly what I need, as if by telepathy. This is the 2nd time this has happened and that’s strange.
Glad to hear it's helpful! Hopefully just by coincidence rather than telepathy :D
Next video is Phil's Lab 'Cerebro'...
Ya. Happened to me as well. He's a weird German....in a positive way
@Phil....great job
If I had a nickel for every time that's happened then I'd have two nickels... Which isn't a lot of nickels, but it's weird that it happened twice.
Dude same wtf
I've learned more electronic design from you than the entire five years of my master's of EE university studies.
Glad to hear the videos are helpful - it's a sorry state of affairs when it's this way round though :(
@@PhilsLab The course was very theory-heavy. We never got to actually design a PCB, build it and bring it up.
Thanks to your videos, I'm more confident now designing my own PCBs.
Me too. 6 yrs of grad and 20yrs of work and I never picked up this much.
@ simple question, do you designed pcb with this complexity at school or it was more soft ?
More ESP32 plz. Great video!
Cheers, Phil. Amazing content.
Amazing project! I'll hope you'll continue with it!
Thanks! Firmware videos coming next :)
Literally the exact video I needed. Don’t forget the strapping pins when developing the board. I forgot to pull in of them high when I was designing the board and it caused it to fail when programming. Once I added a trace to 3v3 it all worked again
Awesome, I've never saw those unique ESP32 design! Thank you for great video.
Thanks for watching!
Phil, congratulations for making such exquisitely detailed videos. You expound every detail, offer practical advice and support for your growing community of subscribers.
Thank you very much for your kind words, Luc!
Thank you Phil for another awesome pcb project video!
Thank you very much for watching!
Once again, a great video and very informative. Looking forward to the further firmware videos with this board.
Thanks, David - firmware video coming out this month!
Awesome video Phil, an absolute joy to watch and learn. Was looking into antennas in general and wanting to learn. This would be a great start! Thanks again!
Thank you very much! Hope this proves to be helpful for your designs :)
This was really what I needed! Created a similar board a few months ago, and this video has really answered a lot of questions I had.
Very glad to hear that, thanks!
100x better than any college course and free. I hope you realize that you’re helping a lot of people!
As a rookie PCB designer, I am always in awe of what you do taking us to the design considerations used to produce boards that we buy off the shelf. I have no intention of reproducing this particular design (obviously above my paygrade) but I enjoyed watching the detail description of this author. Thank you very much professor Phil.
Truly amazing content, a lot of different subjects, HW, SW, indepth practical design. Thank you so much
Thank you for watching, Rick!
@@PhilsLab are you maybe planning on a similar board with some LoRa IC + PCB antenna?
You can use the C3FN4 variant of the ESP32-C3 which has a built-in 4 MB flash memory instead of a dedicated memory.
Nice catch
So, in the C3FN4 variant do you just leave one of the SPI pins as Not Connected or can they be used as normal SPI pins?
@@KPruthviRaajas far as i know, other pins need to be strapped - read the doc!
Super impressive and relevant
I am learning enormous things from your tutorials ....Really thanks
Thanks for watching :)
Thanks for your content! It is amazingly useful for learning. I'm considering to use the ESP32-C3 for my next project 😁
Thanks for watching, Sergio!
i need to say that you are the best embedded systems channel on youtube by far. watching your videos motivate me to learn more and more and tbh comparing myself to last year i've improved a lot in pcb designs and it's thanks to your videos and robert feranec's. hope you continue this quality containt and thanks for the efforts.
Thank you very much, Yacine! I'm glad to hear that - hopefully I can keep up with interesting videos!
Wow I've been working on a bare ESP32 project and have been stuck on the antenna part for a while. This video just comes 2 weeks after, amazing thank you so much!
Glad to hear the timing's right :)
I just want to thank you for your free videos that you release on these topics. It has led me to discover what I want to study in college end goninto as a career. Thanks Phil
That's awesome, thanks!
I have just discovered your channel today and have been watching several of your videos on KiCad and I have picked up a wealth of information, I happen to be in my mid-seventies, a retired electronics design engineer, very much into RF design, and this old dog is still learning new tricks. Well done, Mate! Looking forward to watching more of your Great instructional videos .
Thanks a lot, Harry - glad to have you here! :)
Aww. As someone who’s 25, I always worried that I won’t be able to do as much or learn as much when I’m older because I’m already so much slower than I was since I was a teenager, glad to know that you can still do cool stuff when you age !
I was waiting for a video like this for so long!!! Thanks you Phils
Thanks for waiting! :)
Awesome video!
Nice work 👍👍👍
Very cool video! I design hardware with the ESP32 Wroom modules for work so it's super cool to see a design with the ESP32 C3 chip itself
What does your company make? Seems weird as we are not allowed to use esp32 as it's not 'a real mcu'. We use pic24, FPGAs, etc
Great video Phil! Certainly a project I’m planning on doing at some point. Love the Wi-Fi name!
Haha thanks, Alex!
Thank you! I thought to make custom esp32 board with pcb antenna and after research came up with similar guidelines. But did not make it yet ... :) Now I will have more confidence that this thing will work, can't wait for your next videos!
Thank you, Dmitriy - good luck with your design!
Really good video, explains the design process even to those, who don't know all this.
Thanks you!
great video, always blown away
Thank you, Jack!
your videos are soooo invaluable. thank you
Thank you!
This is amazing. I learned so much.
I made a pcb a couple of weeks ago and I thought I did quite well but I now know there are so many small mistakes in it after seeing this video haha.
It might be fun to do a video about my pcb and point good/bad things out along the way.
Thanks, Emiel! I do design reviews on the channel, if you'd like - send it in via phils-lab.net/contact :)
@@PhilsLab hi thank you for your reply.
I have sent my design in via the link you gave me. If there are any questions please let me know.
I hope my design is not too bad 😬
Great tutorial! Thank you
Thank you!
I was looking for something like this too…. Phils lab is theee best!
Awesome, glad to hear that!
This is fantastic, thanks
Thanks, Juma!
Oh yes exactely what I was waiting for!!! Thanks!
Glad to hear that - thanks for watching!
@@PhilsLab Could the ESP32 c3 also be used to negotiate other USB-PD voltages or would I always need a separate IC for that?
I guess you could try and control the CC lines through the ESP32 directly, but it's far easier to use a dedicated USB C PD IC, which interfaces to ESP32 via I2C, for example.
@@PhilsLab Okay so if it's a size-constrained application it might be possible but if I have the space is probably not worth the hustle. Thanks!
You'll have to add in control circuitry + FETs as well in any/most cases, so I'd definitely just go with a dedicated controller that has the right gate drivers, etc. as well.
I was looking for antenna design for esp all over the internet, but all of them were difficult and I lost hope. Now I got your notification, let's see.
Hope it's helpful!
Golly! great video!!!!!!!!!
Thanks, Tony!
You are Awesome
thank you
Very nice, I was designing esp32 data logger some time ago, and I remember including "reset" circuit connected to the external IC USB to UART and that had Data Terminal Ready and Ready to Send control output connected through two transistors to the EN and BOOT pin on ESP32, that helped with the reset after sketch upload. I wonder if this can be implemented in the SOC when the UART chip is "build in"
Thank you so much , very helpful.
Thanks for watching!
Great video!
I've been working with ESP boards for years now (developing ESPEasy) and I alway wondered what made one board work great with WiFi and why it worked so bad on others.
I really would like to know how the WiFi quality is of this board, compared to other boards when running the same kind of scan at the same location in your house.
Maybe also nice to check running some AP on various channels to see whether you hit the perfect center frequency and what the actual bandwidth/range is of your PCB antenna.
Perhaps let some ESP board run a few meters away, starting AP mode on the next channel every minute and let your board (and others) scan and compare the RSSI values.
Still this will of course also include some offsets caused by the "bad" antenna of the other ESP board acting as an AP.
So maybe you could also test using a real access point and test on channels 1, 6 and 11 to cover the entire 2.4 GHz spectrum.
Also really nice to see those ESP32-C3 are so easy to wire and program due to their internal USB interface.
Meaning I really should start supporting the C3 also in ESPEasy :)
Thank you very much, Phil. We've been producing boards using the ESP32 modules because we haven't found yet an in-depth tutorial on customization such as this and also the concern about FCC compliance.
Thanks for watching! Yeah, FCC compliance of course can be quite a hurdle when going the custom route...
Great video, thank you.
Thanks!
Great video again Phil, love it. I downloaded STM32CubeMX and have been working through the tutorials. The software sounds awesome. I usually use Studio code composer, I might be switching to CudeMX for a while.
Thank you very much, Bill. If you haven't already, I'd highly suggest given the newer STM32CubeIDE a try!
@@PhilsLab I already downloaded it. I got my hands on a STM32 nucleo. I also enjoy using MSP430 series as well.
Thanks
Phil i ove your videos. so clear, clean, ogranized and amazing in general. so informative. please do one with standalon bluetooth audio SOC. I will forever be grateful.
Thank you very much, Srijan!
wow, this is exactly what I have been looking for, the TH-cam algorithm nailed me with this one. Just throwing it out there, but I'd also be really interested in a guide for how to use ceramic antennas in designs
Thanks, Josh - glad to have you here! Great suggestion as well!
For my semester project i literally have to implement an ESP32-C3. It is as if god sent you Phil.
Awesome, good luck with your project!
Finally, this topic😂
Very nice video, TNX Phil.
Thanks, Nicola!
Very nice! Thanks for the video - I enjoyed it as usual. By the way, you should change your wifi access point off of channel 6. According to your new scanner that band looks quite congested :)
Very detailed video about the whole steps that is essential to create an excellent PCB! But I have one suggestion for improvement that you can comment on: It's necessary for PCB antennas to open solder mask above them. Solder mask dielectric constant can dramatically change the characteristics of the created antenna, because it is located in the path of radio waves propagation.
Question: without soder mask, the antenna will then be affected by the finish (ENIG or HAS). Wouldn't that affect also be an unknown variable?
I love it! only thing missing, is a CAN bus IC (SN65HVD230DR). 😅
Ironically as it may sound, I was trying to design a depth measure system using the same MCU and a ToF but I found myself with difficulties specially designing the antenna part.
So thank you once again Phil, for the wonderful surprises, and help you've been giving me. Waiting for your new course.
Very glad to hear that! Thank you for your support, Ricardo :)
Hi Phil, Nice video overall. It was refreshing to hear you admit that there were going to be many external factors that will impact the overall tuning of the onboard antenna. A very realistic approach since the end user can put the board into a completely unknown environment with various other nearby metalic elements which will all impact upon the tuning and performance of the antenna. It was amusing to then see you worry about the PI matching network to match the 35j10 to the 50 ohms (nominal) IFA impedance. If by some chance your antenna ends up at 50 ohms (unlikely in the real world) without any actual verification / trimming then the power loss from the resulting mismatch is still pretty much negligible. All made more novel by the "close enough" values of the PI elements ;-) I realise the whole point is to demonstrate a complete RF path from the chip to the antenna and you did that well. Some people go to extraordinary lengths to try and get the match of some onboard antenna and matching network perfect whilst ignoring the reality that it will only ever be "right" at that moment in time on their bench lol.
Just one more thing, in your layout you had the PI matching network inductor close and parallel to (I think) one of the RF power rail inductors. Personally I'd seperate those or put them at right angles to reduce any possible coupling but it again may make no practical difference! I'm not going to touch the whole solder mask or not issue in the RF path. All the best.
Funny to see you here. I cannot imagine who you may be referring to above... 🫠
Amazing video again 😍
Hope yo do same video for a GPS module
Because i have to put components on the pcb with its antenna but i didn't find much resources
you awesome bro..thanks
Thanks!
Nice bro
Thanks!
Thank you
Thanks for watching, Tim!
THANK YOU FOR THIS!!!!!!!!!!!!!!!!!!!!
I am designing my own ESP32 based board and didnt want to do what everyone else does and just solder on a single ESP32 pre-built board (the one with the wifi antenea and such, not the full dev board, tho i've seen that too).... I am wanting to use the SOC direct and then design my own firmware and setup for it... and the ESP32-S3 is STUPID cheap and so simple!!! I just am getting hung up on the design of the memory and flash and such... I think i'll do an SD card for the flash part... but playing around with options...
I am doing an external antenea plug in on the board since it will be in a case and wanted to have the full range available. But this helps out so much! i've been looking at recommendations from other sites and reading all the SOC documentation inside and out and printed it all out and marking my notes...
This is by far the biggest custom PCB project i've taken on for my own little things... I normally would do the ESP32 and solder the wifi pre-made package board on it. But I wanted something more "professional". Learning to design and build PCB's self taught can be pretty steep learning curve. Only my Electrical Engineering classes in highschool from the late 90's is what I have education wise and all self taught componant diagnosis and repair and small self designed PCBs.
But NO ONE has an SOC totorial for me to go through and verify my design and deployment based off the technical and design documentation from espressif direct.
New sub from me! Love this walk thru! Simplified some of my questions I was dealing with trying to figure out via documentations.
Thanks for the video, it is really informative and I am glad that the content is of such a high quality! I had a couple of questions though. First of all, could you have just connected the antenna ground pin to the GND plane on the top layer. Of course adding a via to GND is also a neccessity there, but it seems against any logic not directly grounding that pin to the top layer of the ground. I checked some designs online and I see this being grounded to the top (if the top pour is GND that is). So potentially did you manage to find some information that was against doing this? Another questions is that I see people adding a picket-fence around the antenna feed line and the antenna itself, which should reduce stray signals from antenna entering the PCB and the opposite. I thought it is quite essential, but you seem to have managed to make it work without adding one. I wonder how would that affect the SNR overall.
Thank you very much for putting time and effort into this great work. I had a question, you interfaced the USB_P and USB_N of the esp-32 with the USB port, thought the USB gives 5 volts which the esp-32 pins can't handle, does this means that the USB ESD Protection will take the 5volts down to a 3.3v, or that the esp-32 USB pins are 5v tolerant.
I used Ti's ISM PCB antenna app note for Lora pcb design, fortunately they had shared gerber so creating footprint was a breeze
I manufactured an ESP32-S2 board and the impedance I got on the RF input was very different from the one on the datasheet ( 11 + 1j vs 31 + 1j ). This means the impedance matching network I designed actually reflected 95% of the signal at the 2.4Ghz carrier frequency, it actually worsened the problem instead of improving it, as removing the network and using a 0 Ohm resistor only reflected 50% of the signal. I have to say my stackup was completely different too from the one recommended in the datasheet. It might be worth to mention to ALWAYS leave an u.FL connector on the board to hook up a vector analyzer in case it doesn't work properly (and it will not if you make even a slight change on the stackup)
I might mention, the change I did to the stackup was using 0.8mm thick 2 layer board instead of 1.6mm thick 4 layer board. It also changed the impedance of the PCB antenna from 50 + 0j Ohms to 30 + 0j Ohms. Luckily I left an u.FL connector in place to know this information, and also pads to solder a Pi Network on the antenna end
Sir, could you tell me in what position did you place the U.FL connector? Was it between the ESP pin and the matching network or between the matching network and the PCB antenna? Thanks.
Your video is great and saved me from making a critical error. I read the docs and didn't see anything about the LNA_IN output impedance (35 + j10) so assumed it was 50 ohm since that's the "standard". Turns out its not listed in the datasheets but is mentioned on the hardware forum.
Thanks, glad to hear that it helped!
Just for anyone watching, there is a version of C3 with built in flash as well (C3FN4, C3FH4, 4MB flash). I've used it on my own board and I thought that meant the SPI pins could be used for other things then but appears that the internal flash is connected to the same pins as they would for external. (yes I know it's stated in the datasheet that these pins are not recommended for other use, but I thought that was fi external flash was used). So good to know so you don't do the same mistake as me. :).
Thanks for the informative video. Is there any guidance on these ground planes on the top layer? Why some designs have them, but others don’t? When holes are required? Why there are some uncovered blanks spots?
This content is worth a lot, I struggle to find books and Udemy courses that will teach me more about embedded systems on this level. Please consider turning some of your work into Udemy courses in future.Thank you.
Could you please make a video on GPS module/ system design
Thanks you Phil for all the videos you´re making, i´ve learn a lot on pcb design thanks to you!!. Great content and very professional. Since you make the antenna design topic, if you can, could you make something on the "gnss" topic?, based on a module or an IC. Once again thanks!!!
Thanks, Giovanni! Is there anything specifically to a system with GNSS you'd like to see? Usually there isn't much to incoporating those modules in designs.
@@PhilsLab You are right!, i want to implement a ublox module (NEO-M8N) and i saw that the most relevant component it´s an inductor on the antena line for active antennas. But my insecurities appear hahahaha.
Wow, really cool. First of all, your video with the ESC FOC controller helped me, because I was experimenting with BLDCs at that time and now this year I wanted to start a project with an esp32. Thanks for that. Will there be another video about the ESC and the FOC? Many greetings Michael. The content on your channel is great and so helpful.
Thanks, Micha. Glad to hear the videos have been helpful. Yes, I'd like to make a follow up vid to the ESC design, however, I have many projects ongoing at once, so it can take a bit of time I''m afraid.
Can you make a video discussing high current or high power switching devices like relays?
Video is gold, I´ve seen extremely few people going over so much detail and the correct reason behind it over the years. And yes, technically you are being a bit naughty with the USB. As per IF-standard you should not draw more than 100mA continuously before enumeration, that being said, you would probably still be fine, if the first thing that you try to do when the device connects is to try to enumerate before activating the RF section. I do not know the C3 specifications, but I would guess, if you really wanted to turn this into a product with the USB-IF approved logo on the outside, it should not be a problem. But rumor has it, they turn a blind eye with a lot of products anyhow.
Wowee, so interesting!
Thanks, Roman!
I enjoy your AP name being "Cheeky WiFi 'n That"
Haha I've been listening to too much Karl Pilkington...
@@PhilsLab "not getting on a camel" is a frequent reference in my household
Thank you so much for making this video. It gives me alot of insight of making pcb board with MCU, i am wondering you like to add CLC pi filter to the power supply and analog supply, any tips for this kind of filter? For eg how to select the right value of the components. Thank you!
After this being the somewhat twenty-x-ish video of Phil I watched, I realised I have not yet subscrided to this channel, which I "fixed" immediately. I would love to hear and see even more about design considerations for EMI/SI ,because at least to me it appears that most people (including me) have still a lot to learn in this field.
Glad to hear that you subscribed!
Definitely will be making more videos on SI/EMC techniques.
I have found SimSmith (free JAVA-based software) excellent for designing various matching networks. Of course, a basic understanding of Smith Charts is needed but the program will choose "standard" values for the various network types you want to implement and give you a pretty good Smith Chart representation of how it should react (also Bode plots).
Yes, I use SimSmith myself sometimes as well - really neat tool.
Phil. Great videos. Leant much. Why did you terminate the GND of the antenna at the GND pour directly instead going have a gap around that leg?
Great video again!
Why did you go for the C line and not the S line? Is it because it is RISK V ?
Also in the future when you will cover more firmware will you use Arduino or the ESP-IDF?
I noticed that the antenna is in the Kicad RF Antenna footprint library as RF_Antenna:Texas_SWRA117D_2.4GHz_Right and RF_Antenna:Texas_SWRA117D_2.4GHz_Left.
Awesome video! Please add firmware videos!
Thanks, Alexandros - firmware vids are coming!
I'm currently working on a SAE Hydrogen powered formula and we need a solution for a boost converter. We found some off the shelf solutions but you are slowly making me get the job of developing it! hahahhaha So cool to make the PCB and also the simulation and control are related to my masters dissertation.
Oh god i will have to much to do this year
Haha glad to hear this is making you do design work! :D
Amazing! Thank you so much for sharing. Did someone send this to PCBway for manufacturing and assembly? I would like to know how expensive it is.
For me the in between here is the Espressif modules. Not dev boards, the modules. They come with the flash already setup under the can and ... quite importanly an FEC Certificate of compliance. The chips on the other hand do not come pre-certified so any product that wants to carry the logo and get an ID has to go through it's own certification, submit it's own test/lab results etc.
FCC* ?
you have to do the FCC testing for the whole device anyway.
@@martincerny3294 true, so why complicate things? Pre-shielded mcus makes it for easier self certification, where acceptable,jurisdictionally, no?
For Antenna i'm just using cracked CST studio. For studying it's very cool.
As always, a quality content from you Phillip. Thank you for this. Can you also explore STM32WB55 mcu for BLE, We are currently had a designed custom board from this but having some RF issues.
Thank you, Ian! The STM32WB* series is definitely something I'd like to feature in upcoming videos.
Thank you for sharing your knowledge with us! Great video, as usual, but I would like something similar made with KICAD if possible.
Yeah mate.
Need more videos in KiCad as I'm a beginner.
Thank you so much for making this great, educational video.
With the implementation of the PCB antenna and matching network, how do you know if the design achieved a low SWR? Is there any practical way of measuring it?
NanoVNA
The Espressif guideline for PCB antenna is no ground plane underneath.
If you want to have a receiver and transmitting antenna (one with high gain) one with low gain, can we use the LNA pin since it's I/O?
The ESP32-C3 looked fun to play with since it's riscv, but I found the wifi/bluetooth and other parts of the device are closed source binary blobs. Would be perfect if they were open sourced. I'm currently looking at the nRF52840 because I *think* the wifi/BLE is open source.
Thanks for the video. It is very informative. I got a question. Is there any minimum or maximum feed line length after the PI filter? and what is the minimum gap length between feed line and ground?
if source impedance value not given in the ic datasheet then how to get value of source impedance for RF matching network
Great videos. It would be great to see the performance of the atenna and the matching network. The USB VNA from Amazon should be a good cheap way of measuring the 50ohm matching. I think they are
Thanks! Yes, I really need to get my hands on one of those.
is rf antenna integrable with any kind of mcu? i'm asking because i bought sygonix minicam and i want to integrate antenna and connect it with wifi to make it remote.