Electronics-Related.com
Forums

PIN diode for RF switching

Started by Ralph Mowery April 2, 2023

Can anyone recommend a PIN diode that can be used for up to switching a 
RF amplifier in and out of the transmission line at 150 MHz and 450 MHz.

The powewr level ia 50 watts RF.

On 4/2/2023 11:57 AM, Ralph Mowery wrote:
> > > Can anyone recommend a PIN diode that can be used for up to switching a > RF amplifier in and out of the transmission line at 150 MHz and 450 MHz. > > The powewr level ia 50 watts RF. >
This guy gives a great tutorial on PIN diode switches and mentions that the one he is showing was used in a 50W transceiver. Maybe helpful. <https://www.youtube.com/watch?v=XpYsCM_Wf50> -- Dogs make me happy. Humans make my head hurt.
On Sun, 2 Apr 2023 12:57:12 -0400, Ralph Mowery
<rmowery42@charter.net> wrote:

> > >Can anyone recommend a PIN diode that can be used for up to switching a >RF amplifier in and out of the transmission line at 150 MHz and 450 MHz. > >The powewr level ia 50 watts RF.
I've used MACOM pins, but only tiny ones, basically signal level. I used them for switching attenuators in and out in a pulse application, which didn't work well. Pulses got distorted more than I expected. If you don't need switching speed, you might consider a relay. I like the tiny, cheap Fujitsu telecom parts, which are sure easy to drive compared to a PIN. https://www.dropbox.com/s/se162xpw86hpmzs/DSC06884.JPG?raw=1
Am 02.04.23 um 19:16 schrieb John Larkin:
> On Sun, 2 Apr 2023 12:57:12 -0400, Ralph Mowery > <rmowery42@charter.net> wrote: > >> >> >> Can anyone recommend a PIN diode that can be used for up to switching a >> RF amplifier in and out of the transmission line at 150 MHz and 450 MHz. >> >> The powewr level ia 50 watts RF. > > I've used MACOM pins, but only tiny ones, basically signal level. I > used them for switching attenuators in and out in a pulse application, > which didn't work well. Pulses got distorted more than I expected.
PINs do not work well when there a frequencies below 2 MHz involved. Some go a little bit deeper, but not much. And carrier lifetime is unknown to Spice, so the simulations are not realistic. Gerhard
On 4/2/2023 12:46 PM, Gerhard Hoffmann wrote:
> Am 02.04.23 um 19:16 schrieb John Larkin: >> On Sun, 2 Apr 2023 12:57:12 -0400, Ralph Mowery >> <rmowery42@charter.net> wrote: >> >>> >>> >>> Can anyone recommend a PIN diode that can be used for up to switching a >>> RF amplifier in and out of the transmission line at 150 MHz and 450 MHz. >>> >>> The powewr level ia 50 watts RF. >> >> I've used MACOM pins, but only tiny ones, basically signal level. I >> used them for switching attenuators in and out in a pulse application, >> which didn't work well. Pulses got distorted more than I expected. > > PINs do not work well when there a frequencies below 2 MHz involved. > Some go a little bit deeper, but not much. > And carrier lifetime is unknown to Spice, so the simulations > are not realistic. > > Gerhard > >
Ummm... he says 150 to 450 MHz. That's a bit higher than 2MHz. -- Dogs make me happy. Humans make my head hurt.
In article <0mdj2i9ntgmu2upudncd09u97clbs14iv4@4ax.com>, 
jlarkin@highlandSNIPMEtechnology.com says...
> > I've used MACOM pins, but only tiny ones, basically signal level. I > used them for switching attenuators in and out in a pulse application, > which didn't work well. Pulses got distorted more than I expected. > > If you don't need switching speed, you might consider a relay. I like > the tiny, cheap Fujitsu telecom parts, which are sure easy to drive > compared to a PIN. > > https://www.dropbox.com/s/se162xpw86hpmzs/DSC06884.JPG?raw=1 > > >
Problem is I need the speed. Just thinking I forgot about the 100 watt amp I have so needs to handle 100 watts at 450 MHz. Project is using an amplifier to get more power for a DMR radio at 450 MHz. There is not much difference in driving the PIN or relay as this is going to be RRF switched and not hard wired.
On 03/04/23 04:45, Ralph Mowery wrote:
> In article <0mdj2i9ntgmu2upudncd09u97clbs14iv4@4ax.com>, > jlarkin@highlandSNIPMEtechnology.com says... >> >> I've used MACOM pins, but only tiny ones, basically signal level. I >> used them for switching attenuators in and out in a pulse application, >> which didn't work well. Pulses got distorted more than I expected. >> >> If you don't need switching speed, you might consider a relay. I like >> the tiny, cheap Fujitsu telecom parts, which are sure easy to drive >> compared to a PIN. >> >> https://www.dropbox.com/s/se162xpw86hpmzs/DSC06884.JPG?raw=1 >> >> >> > > Problem is I need the speed. Just thinking I forgot about the 100 watt > amp I have so needs to handle 100 watts at 450 MHz. > > Project is using an amplifier to get more power for a DMR radio at 450 > MHz. > > There is not much difference in driving the PIN or relay as this is > going to be RRF switched and not hard wired.
You might succeed in using an old (slow) power rectifier diode, which has PIN structure. You need to provide enough forward current to conduct without (much) waveform distortion, and more than the peak RF voltage to turn it off, but that's all PIN diodes. The only real question is whether the off capacitance (reverse biased) provides enough attenuation, but if not, use more stages. Clifford Heath.
Am 02.04.23 um 20:04 schrieb John S:
> On 4/2/2023 12:46 PM, Gerhard Hoffmann wrote: >> Am 02.04.23 um 19:16 schrieb John Larkin: >>> On Sun, 2 Apr 2023 12:57:12 -0400, Ralph Mowery >>> <rmowery42@charter.net> wrote: >>> >>>> >>>> >>>> Can anyone recommend a PIN diode that can be used for up to switching a >>>> RF amplifier in and out of the transmission line at 150 MHz and 450 >>>> MHz. >>>> >>>> The powewr level ia 50 watts RF. >>> >>> I've used MACOM pins, but only tiny ones, basically signal level. I >>> used them for switching attenuators in and out in a pulse application, >>> which didn't work well. Pulses got distorted more than I expected. >> >> PINs do not work well when there a frequencies below 2 MHz involved. >> Some go a little bit deeper, but not much. >> And carrier lifetime is unknown to Spice, so the simulations >> are not realistic. >> >> Gerhard >> >> > > > Ummm... he says 150 to 450 MHz. That's a bit higher than 2MHz.
No. JL wrote about a pulse application with unknown (to us) switching times. Gerhard
On Mon, 3 Apr 2023 01:24:03 +0200, Gerhard Hoffmann <dk4xp@arcor.de>
wrote:

>Am 02.04.23 um 20:04 schrieb John S: >> On 4/2/2023 12:46 PM, Gerhard Hoffmann wrote: >>> Am 02.04.23 um 19:16 schrieb John Larkin: >>>> On Sun, 2 Apr 2023 12:57:12 -0400, Ralph Mowery >>>> <rmowery42@charter.net> wrote: >>>> >>>>> >>>>> >>>>> Can anyone recommend a PIN diode that can be used for up to switching a >>>>> RF amplifier in and out of the transmission line at 150 MHz and 450 >>>>> MHz. >>>>> >>>>> The powewr level ia 50 watts RF. >>>> >>>> I've used MACOM pins, but only tiny ones, basically signal level. I >>>> used them for switching attenuators in and out in a pulse application, >>>> which didn't work well. Pulses got distorted more than I expected. >>> >>> PINs do not work well when there a frequencies below 2 MHz involved. >>> Some go a little bit deeper, but not much. >>> And carrier lifetime is unknown to Spice, so the simulations >>> are not realistic. >>> >>> Gerhard >>> >>> >> >> >> Ummm... he says 150 to 450 MHz. That's a bit higher than 2MHz. > >No. JL wrote about a pulse application with unknown (to us) >switching times. > >Gerhard
It was a shaped pulse, max 25 ns wide, that modulates a rather large laser. The PIN lifetime is specified at 200 ns, but maybe that means really, really depleted. At any rate, the PIN wrecked the waveform. This was a home-made single-step attenuator, and the PIN was an on/off switch to ground; I expected that to work. I changed it to a SAV541 phemt, which worked fine.
On Sunday, April 2, 2023 at 9:57:20&#8239;AM UTC-7, Ralph Mowery wrote:
> Can anyone recommend a PIN diode that can be used for up to switching a > RF amplifier in and out of the transmission line at 150 MHz and 450 MHz. > > The powewr level ia 50 watts RF.
I haven't looked for awhile, but check Macom. They bought Metelics too, so they have a lot of stuff. Skyworks had some stuff too, but less of a selection. I was looking into stuff at that power, but higher frequency. Chip'n'wire microcircuit stuff. But these companies have the diodes.