Replying to Avatar A.A.Ron

By convention, the impedance of the final amplifier stage in radio transmitters is 50 ohms. You get maximum power transfer from the amplifier to antenna when the load and source impedance match.
Avatar
Ruminant Llama 1y ago

I'm familiar with impedance matching and the resulting efficiency. But still - If free space is 376 Ohm then why not match it to this impedance?

Reply to this note

Please Login to reply.

Discussion

Avatar
A.A.Ron 1y ago

Good point. I believe that 50 ohms was selected because it was efficient and practical to build 50 ohm coax.

Avatar
LO₿ONODE 1y ago

Antennas are actually designed to be matched to free space intrinsic impedance of 377 ohm. They are basically working as a matching network that converts that 377 ohm down to 50 ohm. Good question!