I just came across your channel and I have to say I found exactly what I was looking for for long time. Your channel presents very informative content in easy to understand commentary. I am not ham radio operator but in some cases I can use this information for higher frequencies designs. I need your advice for one of my multiband antenna design for 915 mhz LoRa band, 1575 mhz GPS band and 2.4 ghz WiFi band. I wanted to use this one antenna for all 3 bands at the same time. GPS is only for receiving but other 2 bands receive and transmit. I have following simulated results for all bands: Frequency Gain Antenna VSWR Impedence Antenna height MHZ DBi Pattern Real Moderate gnd 915 (LoRa US) 2.28 Omnidiectional 1.64 60.7+j25.50 Free space 915 (LoRa US) 8.31 Omnidiectional 1.66 60.8+j26.10 3 feet 1575 (GPS) 3.19 Omnidiectional 7.13 356+j5.83 Free space 1575 (GPS) 9.21 Omnidiectional 7.12 356+j6.07 3 feet 2440 (WiFi) 4.53 Omnidiectional 1.63 73.9-j18.00 Free space 2440 (WiFi) 10.60 Omnidiectional 1.62 73.6-j18.00 3 feet My question is how to design either PCB impedance matching network or Coax impedance matching network so that it can be matched to 50 Ohms feed lines. Thank you.
Yes, that is correct. The only issue is the PCB is designed for 75 Ohm F-connectors, so using those F connectors you would need to use an adapter for a 50 Ohm coax connector.
@@ve6wz I just posted my splitter+LNA design in the RTLSDR subreddit, I wonder if you could take a look. I have a couple questions, but I cannot post a link to my schematics here.
Your videos are a Ham's must view. Excellent series. Nice to see a new video. 73!
Sir, Wow! It's always a learning experience with all you do. More, Please?
Steve
Thanks for another great video.
Lots of good info in all you're videos thank you very much.
Fred KB4QZH
I just came across your channel and I have to say I found exactly what I was looking for for long time. Your channel presents very informative content in easy to understand commentary. I am not ham radio operator but in some cases I can use this information for higher frequencies designs.
I need your advice for one of my multiband antenna design for 915 mhz LoRa band, 1575 mhz GPS band and 2.4 ghz WiFi band. I wanted to use this one antenna for all 3 bands at the same time. GPS is only for receiving but other 2 bands receive and transmit. I have following simulated results for all bands:
Frequency Gain Antenna VSWR Impedence Antenna height
MHZ DBi Pattern Real Moderate gnd
915 (LoRa US) 2.28 Omnidiectional 1.64 60.7+j25.50 Free space
915 (LoRa US) 8.31 Omnidiectional 1.66 60.8+j26.10 3 feet
1575 (GPS) 3.19 Omnidiectional 7.13 356+j5.83 Free space
1575 (GPS) 9.21 Omnidiectional 7.12 356+j6.07 3 feet
2440 (WiFi) 4.53 Omnidiectional 1.63 73.9-j18.00 Free space
2440 (WiFi) 10.60 Omnidiectional 1.62 73.6-j18.00 3 feet
My question is how to design either PCB impedance matching network or Coax impedance matching network so that it can be matched to 50 Ohms feed lines.
Thank you.
As always, very educational 73! de LA7THA
Another useful video Steve - tnx! Which PC board fabricator are you using?
I use JLCPCB.
To make it 50 Ohm, I only need to change the resistors, 150 Ohm to 100 Ohm and 75 Ohm to 50 Ohm? Also, can this be used in the 470 Mhz range?
Yes, that is correct.
The only issue is the PCB is designed for 75 Ohm F-connectors, so using those F connectors you would need to use an adapter for a 50 Ohm coax connector.
@@ve6wzThanks. I'm planning to make my own PCB. But I just found the Mini-Circuits SCA-4-10+, I think I will use that.
That looks like an easy solution if you plan to build up your own board. Numbers look good.
@@ve6wz I just posted my splitter+LNA design in the RTLSDR subreddit, I wonder if you could take a look. I have a couple questions, but I cannot post a link to my schematics here.