RF Project

[ParkerWeb]

Hey! I'm building a 24 GHz FMCW radar from scratch this summer as a personal project (this is my first RF project I have designed two pcbs before (not RF)). The idea is that the radar transmits a chirp and when it bounces off an object, the echo comes back slightly delayed. By mixing the transmitted and received signals together, I get a LF beat signal whose frequency tells me how far away the object is. By transmitting many chirps in sequence and tracking how the phase of that beat signal shifts from chirp to chirp, I can also extract the velocity of moving objects. I'm designing a custom microstrip patch antenna array on Rogers 4003C substrate and Im using the BGT24MTR11 chip from Infineon which handles the 24 GHz signal generation and mixing, and processing everything in real time on an STM32H7 microcontroller running range and Doppler FFTs. The end goal is a working radar that can detect objects, measure their distance to centimeter-level accuracy, and show a live range-Doppler map on my laptop.Do you think this is a reasonable project for my first RF project and as a junior in EE? what are your recommendations ?

 

[prcguy]

I've built a lot of instrumentation radar VHF through 96GHz but designed by someone else. Timing can be critical depending on pulse width and the timing circuits were more complex than the RF parts. Sounds like you have an ambitious project.

 

[K4EET]

Do you think this is a reasonable project for my first RF project and as a junior in EE?

I take it that you are a junior in college? My first EE lab project was taking an old VHF pager and converting it into a FM radio for music (non-tunable and non-stereo). Due to its poor sensitivity based on my modifications, it was set to the school’s FM radio station run by students next door to the EE lab. That was quite an undertaking where we could only use parts we found in the school’s electronics junk bin. That was back in the mid-1970s. By the way, the audio sounded terrible! 😂

Your first EE project sounds like a real challenge, especially starting from scratch. Technology is a lot different 50-some years later. I would probably take on a project like yours if I were in school today and be darn proud of my project when it came alive and did what it was designed to do! Best wishes to you and have fun with your project!

 

[ParkerWeb]

I've built a lot of instrumentation radar VHF through 96GHz but designed by someone else. Timing can be critical depending on pulse width and the timing circuits were more complex than the RF parts. Sounds like you have an ambitious project.

That's really helpful context, thank you! I'm using the BGT24MTR11 MMIC which handles the chirp generation internally, so the timing complexity is somewhat abstracted but I'm realizing the chirp trigger timing and ADC sampling synchronization on the STM32H7 side is something I need to think carefully about. Did you find that timing issues were more of a problem at certain frequency ranges or pulse widths?

 

[ParkerWeb]

I take it that you are a junior in college? My first EE lab project was taking an old VHF pager and converting it into a FM radio for music (non-tunable and non-stereo). Due to its poor sensitivity based on my modifications, it was set to the school’s FM radio station run by students next door to the EE lab. That was quite an undertaking where we could only use parts we found in the school’s electronics junk bin. That was back in the mid-1970s. By the way, the audio sounded terrible! 😂

Your first EE project sounds like a real challenge, especially starting from scratch. Technology is a lot different 50-some years later. I would probably take on a project like yours if I were in school today and be darn proud of my project when it came alive and did what it was designed to do! Best wishes to you and have fun with your project!

Thank you so much! I love that story, the creativity of working with whatever you could find sounds like an incredible engineering training. And yes! I just finished my junior year in college and I've just started a hardware coop this summer (It will be for 12 months). I'm hoping to land a RF focused internship before starting my senior year, next summer. Really appreciate the encouragement from someone with 50 years in the field!