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Please suggest Schottky diodes for RF mixer 10...20GHz range, 3-pin SOT323 or like.

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Hello! I am searching for 3-pin Schottky diodes. Two diodes connected in series in one SOT package. Diodes i use recently worked okay, but mixer sensing is poor. I searched in internet for rf mixing diodes and found BAT15 and some other diodes designed specially for rf mixer usage. But i cant buy them. So i am searching for such diodes in SOT package with average performance. I tried 6 types of diodes from old pcb. Only two worked in rf, and only one with acceptable performance. Although i found excellent diodes on the market but actually they are too small and difficult to use in hobby project, as it uses some kind of thin wire welding under microscope! Maybe there are some 4-pin alternatives, with one pin NC.
 

Whould it perform better than hsms-2822 with capacitance Ct of 1pF, and BAT-64 typical is 4pf?
Datasheet on hsms-2822 states, that it can be used for mixers up to 6GHz, performance in my 11Ghz mixer is average - the same as some unknown diode from old board. I did not found GHz range notes on BAT-64, so it is difficult to guess.

Also i found theese ones: SMS7621-096 (up to 26GHz and higher applications).
SMS7621-060,SMS7630-061,DMF2828-232/222,DMF2831-232/222,DMF2833-232/222 and BAT15-124. But did not found the place where i can buy small amount of them (4-5pcs, as they are different kind), minimum amount is about thousand of them.
 

there is not a prayer of chance an SOT package will work at 20 Ghz. Don't even bother.

Beam lead or wirebond is best, but if you need surface mount, you can use something like this:
**broken link removed**

in that CS19 package
 
Maybe in theory is true, but in practice a made a quick change of a HSMS microwave type diode with a BAT15-AW (SOD 323) and there was no difference up to 18GHz, which was the limit of that particular circuit.

This selection guide of Schottky diodes prove the same, and give the high frequency limit for various packages and diodes:

**broken link removed**
 
Found many guides at rfmicrowave.it, thanks.

One more question. Is it good idea to try ZBD (zero bias detector) or so called Detector diodes in mixer? As such diodes have very low barrier and more sensitive, or there is some problem with that?
 

hi ..
now i am duing my design related the attached paper but i dont know how to plot the Efficiency verses Power(dBm) curve .pls any one simulate and tell me. thanks in advance.please reply soon.
 

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