donkehote
Newbie level 4
I am working on a PA design that is supposed to work upto 3 GHz. It seems that some of the designs I have come across in my study use an Murata High frequency wirewound inductor in series with an RF bead for the bias. I understand that the purpose of an RF choke is to present a large impedance and choke out the resonance, while letting the dc go. However I dont understand why an RF bead would be used in series with the large inductor.
The value of the large inductor is 880 nH, with an SRF at 200 MHz, and the RF bead is a ferrite chip bead rated at 1000 ohms, and 200 mA.
I understand that the RF bead is usually added as a series element with a choke to make a broad band choke. How exactly does it accomplish that. Can someone please explain it from first principles. I would be really grateful.
Thanks,
DK
The value of the large inductor is 880 nH, with an SRF at 200 MHz, and the RF bead is a ferrite chip bead rated at 1000 ohms, and 200 mA.
I understand that the RF bead is usually added as a series element with a choke to make a broad band choke. How exactly does it accomplish that. Can someone please explain it from first principles. I would be really grateful.
Thanks,
DK