I want to thank everyone for their input. I have a sketch of a circuit with the
diodes series connected for DC purposes and paralled for the RF.
A word on the bias:
The 2110 diode is specifically designed for low frequency applications with a
long
minority carrier lifetime of 25uS typical.
Also, its forward bias requirements are different from most other PIN diodes I
have seen.
None of the curves provided indicates more thatn 100ma needed per diode to
acheive the
minimum series resistance. The 250ma spec I gave earlier was for 2 diodes. On
the reverse
bias, the minority carrier lifetime is very long, so I believed I could get
away with the -80V on 1.8Mhz in
a well matched system. The VSWR shutdown sense is after the PIN switch (on
paper), so I can
preserve the diodes hopefully.
For anyone interested, the spec for the diode is at:
http://www.microsemi.com/datasheets/WT6-13.PDF
And Microsemi has published a design handbook which is wonderful. I don't know
if it is a repeat
of the Unitrode, book, but I suspect so.
George K. Watson
K0IW
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