EMRFD Message Archive 747

Message Date From Subject
747 2007-05-10 16:43:12 Kevin Purcell Using a diode ring DBM as an 50dB range current controlled attenuat
A useful trick ... using a diode ring DBM as an 50dB range current
controlled attenuator with a 50dB range.

From

<http://www.minicircuits.com/pages/pdfs/mxr1-25.pdf>

> Q. I need to attenuate low frequencies, from 1 KHz to 2 MHz, and
> PIN diode attenuators won't do the job. Can I use a DBM for this
> application?
>
> A. Yes. A DC current flowing thought the IF port can provide
> isolation or attenuation between the LO and RF ports. With no
> current through the IF port, maximum attenuation (50 dB or more)
> exists between the LO and RF ports. As IF port current flow
> increases, attenuation decreases to about 2 dB.


--
Kevin Purcell
kevinpurcell@pobox.com