Schottky diodes for RF application

Dec 09, 2019 3 Replies
A

Could someone here shed some light on this ? I am experimenting with envelope detection at RF frequencies with SPICE. The mixer is a simple SPICE B signal source as B0 3 4 V(1)*V(2) where



1, 2 are the nodes at which the two signal sources are attached. THe mixer output is fed into a Schottky diode(1N5818, BAR42 etc.,) and a shunt capacitor is attached to the Schottky diode cathode. However, the diode input signal looks identical to the output - no envelope is detected. So, could someone suggest some Schottky diodes that might work at 100 MHz - 500 MHz range, and where could I get their SPICE device models. Thanks in advance for your help.
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B

Do you have an inductor to ground on the door input? And capacitor resistor on output?

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J

It's not likely that a different diode will help. You can't just throw something together and expect it to work.

For starters, tell us the frequencies and the amplitudes of your sources.

Jeroen Belleman

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J

What's your frequency? Power schottkies have huge capacitances, basically a short at RF.

We use tiny low-barrier RF schottkies, like SMS7621 or BAT15 for fast RF detection and switching.

We did a signal detector recently for our I/Q modulator project. We thought it would be cool to light up LEDs when the customer applied a carrier.

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I have Spice sims for that somewhere. Oh, here it is:

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John Larkin Highland Technology, Inc lunatic fringe electronics
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