I am a beginner in antenna design and tuning.
I want my antenna to have a resonant frequency of 2.45GHz for low-energy Bluetooth communication, and I want to know what to consider for the matching process.
I have made some measurements of my antenna with a NanoVNA. I have a resonance frequency of 2.28GHz and at this frequency, I have an impedance of 47.8-7.06j.
Can I take the value of this impedance at this frequency for the matching process or do I have to take the value of impedance at 2.45GHz?
Where should I take the value of impedance for tuning?