Author Topic: Current requirement for a microwave switch  (Read 1468 times)

0 Members and 1 Guest are viewing this topic.

Offline medical-nerdTopic starter

  • Regular Contributor
  • *
  • Posts: 198
  • Country: gb
  • What's that coming over the hill?
Current requirement for a microwave switch
« on: February 08, 2017, 11:12:37 pm »
Hiya all

I have a number of presumably pin diode SPDT microwave switches originally from a military receiver.
MVS P/N 2S3020-93   SC00131-01

These require +/-5V

I have a low noise supply that provides +/- 6V that I want to use.
I have done the usual searches over the past few months and have found nothing regarding these.
Other microwave switches have a supply voltage tolerance of 5% so I was going to use a 5.1V zenner as a shunt regulator to drop down the voltage, presuming that the current requirement would be relatively low.

However I can't find information on current requirements - can anyone give a ballpark figure??

I have considered using the voltage drop from a silicon diode but since I don't know what this beasties tolerances are do not want to risk breaking it since they are obviously irreplaceable. (and I don't want to go down the LDO regulator route, I'm already having difficulties since the beastie I'm building has voltage requirements of +/-5V, +6.5V, +8.5V  +/-12V, +15V, +/-24V, +30V).

Cheers

Steve
'better to burn out than fade away'
 

Offline TimFox

  • Super Contributor
  • ***
  • Posts: 7948
  • Country: us
  • Retired, now restoring antique test equipment
Re: Current requirement for a microwave switch
« Reply #1 on: February 08, 2017, 11:27:25 pm »
A reverse-biased PIN diode (switch OFF) needs only the low leakage current.  The reverse voltage needs to be larger than the peak AC voltage.
When forward biased (switch ON), the device requires sufficient DC current to pass the AC current at the operating frequency.
The stored charge is the product of the DC bias current and the storage time (diode parameter), and the stored charge must be larger than the integral of the AC current over a half cycle at the lowest operating frequency.
 

Offline medical-nerdTopic starter

  • Regular Contributor
  • *
  • Posts: 198
  • Country: gb
  • What's that coming over the hill?
Re: current requirement for a microwave switch
« Reply #2 on: February 08, 2017, 11:31:59 pm »
I have other pin diode rf switches that I know have integrated electronics for control of switching - thus my noobie question.

cheers

Steve
'better to burn out than fade away'
 

Offline medical-nerdTopic starter

  • Regular Contributor
  • *
  • Posts: 198
  • Country: gb
  • What's that coming over the hill?
Re: Current requirement for a microwave switch
« Reply #3 on: February 08, 2017, 11:52:22 pm »
Application notes such as MACOM AN3021  PIN Diodes for Microwave Switch Designs give an impression of a shunt bias of 10-20mA per diode plus current for the driving electronics for the device- or am I misinterpreting this

cheers

Steve
'better to burn out than fade away'
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf