I don't know that shortening it even more makes all that much difference. You can guestimate the loss and to a first order, you're looking for reasonably flat S11 across your band, right? So if 174 it's <1 dB round trip, and you get -10 dB S11, then it's probably really something like -9.
How picky is your source about reflected power?(most low power sources aren't very picky)
-10 dB is only 10% reduction in radiated power (assuming it doesn't reflect back to the antenna and get radiated <grin>)
Those antennas aren't super efficient anyway.
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-----Original Message-----
From: <
[email protected]>
Sent: Feb 24, 2025 10:21 AM
To: <
[email protected]>
Subject: Re: [nanovna-users] Am I in the right track ?
Let me apologize if my yesterday's post was not clear. The pictures I posted are actually the result of the recommendation you gave me. I took a 30cm RG-316 cable I have and calibrated at the very end. Then I made a 6in RG-174 from that end that connect on the pcb. I added a 760ps delay to compensate for the RG-174. Tonight I will try to shorten it as much as I can and some measurements.
The radio transceiver I intend to use has a 50ohm output. The feedline I created on the pcb should also be a 50 ohm line. I made the pcb fabricated with controlled impedance. This way, the fab house provides the dielectric constant of the pcb stack up and provide trace width recommandation to achieve the desired impedance, which I followed. The antenna I chose is also 50ohm.
I will follow up.
Thanks again
