Hi Kent, nice to see you here. I have a couple of your pcb logper antennas (850-6500 MHz) that I use in my lab. Great antennas, real bargain!
Tip for buyers: buy 2 of them, then you can measure the gain of these antennas with your NanoVNA. No need for an expensive calibrated antenna if you need to do some serious measurements.
Reinier
Op 28-10-2020 om 13:09 schreef KENT BRITAIN:
toggle quoted message
Show quoted text
Except for the high dollar RF materials, yes the Er of common fiberglass
PCB material does change with frequency!!
The Er = 4.4 measurement is made at 1000 Hz!?? Audio range.
By the time you get to 2.4 GHz is has dropped to the 3.8-3.9 range
I have made thousands of antennas on FR4 type materials.
Kent WA5VJB
On Wednesday, October 28, 2020, 2:47:03 AM CDT, Erik Kaashoek <erik@...> wrote:
And here is the 0-2GHz scan of a 3cm coplanar stripline on FR4 that seems to confirm the impedance is changing with frequency
The marker is at 1GHz
