Pin-diode choice for high power applications

[el_coronel]

Hi there.

I'm curios now with a choice of a pin-diode for a high power switch.
The power conditions are:

• Ppeak = 1 kW;
• Pcw = 40 W;
• tpulse = 4 us;
• doble gaussian pulse

Also average power might be decreased down to 10 W, while peak power would be still 2.1 kW (it depends on quantity of pulses).

There are few point that confounding me:

1. Which concrete power should be used for diode choice? I used to belive that in this case CW power shoud be compared with diode dissipation power through the well-known formulas. However in case of high duty cycle, I suppose, peak power becomes more relevant. Here I have a paradox: power strengh of a diode decrease with decrease of average power.
2. Breakdown voltage. I also used to belive, that this parameter characterize a value of voltage, that diode can handle in a closed state. In other words, I should calculate voltage from the signal power through a diode resistance in a closed state. If it is true, again the question is, what type of powe should be used.

Thank you in advance!

 

[G4BCH]

Before you design your switch you need to know something about the components you will be using try this, 'The PIN Diode Designer's Handbook' for a start.

https://www.microsemi.com/sites/default/files/datasheets/Products/rf/PAGE1.pdf

A Google search for 'PIN diode switch design' will get a number of other application notes and other design material from various manufacturers.

Since you are asking quite a basic question (nothing wrong with that, it is good, we all have to learn) a word of caution if this is not a paper excercise, get it wrong and high power RF and microwave BITES, and can bite hard in more ways that the immeadiately obvious.

Peter

 

[el_coronel]

Well, yes, thanks, everything fell into place.

The Avago pin-diode handbook seems to be most relevant in the regard of high power switches issue.

 

[G4BCH]

Be aware that since Broadcom took over the Avago line of semiconductors that most if not all the descrete semiconductors have been made obsolete; last ime buy is I think June this year. There are still other manufacturers, but they are getting fewer and fewer.

Peter

 

[el_coronel]

Thanks for the heads-up.

I only talked about theirs pin-diode handbook. I use Microsemi diodes.