EMRFD Message Archive 7822

Message Date From Subject
7822 2012-09-29 14:35:49 Chris Trask Active Loop Antenna Circuitry
Much of the time I spend with electronics these days has to do with
circuitry that is directly related to loop antennas, both active and
passive. In the past week I have designed an amplifier with close to zero
ohms input impedance:


as well as a pair of stable active negative inductors for cancelling the
inductive reactance of loop antennas:


The two used together should make a pretty interesting active loop

7824 2012-09-30 08:16:52 Brooke Clarke Re: Active Loop Antenna Circuitry
Hi Chris:

Have you done any comparis
7825 2012-09-30 08:21:48 Chris Trask Re: Active Loop Antenna Circuitry
> Have you done any comparison testing?

No, not yet. I've been trying to devise a realisable active negative inductor for years, and this is the first time I've come up with just one circuit that PSpice says will be unconditionally stable. I'm anxious to try out the Bipolar NIC version as it has the best overall NF and IMD potential. If it works out, then I'll combine one with the low input resistance amplifier and see how well they play together.

Chris Trask
Senior Member IEEE