I agree with Ed that there is no problem using switches, but I don't see the need for 18 GHz, all the measurements you describe stop at 30 MHz. I don't see why Mini-Circuits would be out-of-line here, and you can check losses by using a tracking generator or known signal sources.
---------- >From: "Price, Ed" <[email protected]> >To: [email protected] >Subject: RE: Coaxial Switches - use with spectrum analyzer and gear? >Date: Thu, May 23, 2002, 11:53 AM >>-----Original Message----- >>From: Jim Eichner [mailto:[email protected]] >>Sent: Wednesday, May 22, 2002 12:55 PM >>To: [email protected] >>Subject: RE: Coaxial Switches - use with spectrum analyzer and gear? >> >> >> >>In our pre-compliance lab, we've got a pair of LISN's, a LISN-mate type >>thing that I'll call a DMRN (DM rejection network), a >>transient limiter, >>some clamp-on RF current probes, an amplifier, the front end of the >>analyzer, and a 50 ohm terminator. All this gear is connected and >>unconnected a hundred times a day when we're deep into >>trouble-shooting, and >>I'm sick of doing up and undoing coax connectors. I don't >>trust push-on >>coax connectors. >> >>What I envision is a system with a few of these coax switches >>in it. The >>analyzer input would go to a switch that selected either the >>amp (used only >>with the clamp-on probes) or the transient limiter (used with >>the LISN's). >>The limiter input would go to a switch that selected between >>the output of >>the DMRN or the Line LISN or the Neutral LISN. Etc. You get the idea. >> >>Is there anything to stop me from using coax switches with suitable CW >>power, insertion loss, and frequency spec's? Am I headed for >>trouble if I >>have 2 or 3 of these switches in the signal path, due to cumulative >>insertion loss? >> >>Thanks for your feedback, >> >>Regards, >>Jim Eichner, P.Eng. >>Manager, Engineering Services >>Xantrex Technology Inc. >>Mobile Power >>web: www.xantrex.com <http://www.xantrex.com> >>Any opinions expressed are those of my invisible friend, who really >>exists. Honest. >> > > > Jim: > > There's no reason why you can't implement the switching system you > described. The only concern is that you use really good parts. (Your > spectrum analyzer likely has a couple of internal relays in its signal > path.) Since you likely need to measure up to about 5 GHz, I would use > components rated for up to 18 GHz. This is not the place to skimp on cost. > Don't use Dow-Key relays with SO239 UHF connectors; go with something like > Agilent relays with SMA connectors. Connect the internal paths with > semi-rigid solid-wall coax, and use a good grade of flexible external coax > cabling too. If your system is computer-controlled, you can use something > like an IEEE488 Relay Driver interface to automate the switching functions. > > Your lab procedures should be amended to include some type of periodic > verification of the loss along all signal paths. > > Regards, > > Ed > > Ed Price > [email protected] > Electromagnetic Compatibility Lab > Cubic Defense Systems > San Diego, CA USA > 858-505-2780 (Voice) > 858-505-1583 (Fax) > Military & Avionics EMC Services Is Our Specialty > Shake-Bake-Shock - Metrology - Reliability Analysis > > ------------------------------------------- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > [email protected] > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Ron Pickard: [email protected] > Dave Heald: [email protected] > > For policy questions, send mail to: > Richard Nute: [email protected] > Jim Bacher: [email protected] > > All emc-pstc postings are archived and searchable on the web at: > http://ieeepstc.mindcruiser.com/ > Click on "browse" and then "emc-pstc mailing list" > ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
