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The task is to test multiple DUT's (sequentially) for Transmitter & Receiver testing in multiple unlicensed frequency bands supported by the DUT. I could connect a single RF Signal Generator to 2 DUT's either using a 2:1 Power Splitter or an SPDT RF Switch.

I understand that Port Isolation for Power Splitter is usually lower (~30dB?) compared to an RF Switch (~90dB?) between the 2 output ports. But I am curious (assuming all the ports are well terminated with 50 ohms attenuators), which would be a preferred way to test a particular DUT at a time?

I also understand the RF Switch + Controller assembly could be expensive, but I am trying to understand the application differences between the 2, accuracy-wise, or understand does the comparison even make sense.

The setup is fairly straigh forward, VSA/VSG connected to 2 to 1 splitter/combiner OR SPDT switch which is connected to 2 DUTs. Its a 2.4/5 GHz 802.11 abgn signal, testing Rx signal at -70 dBm sensitivity PER test and Tx signal at 20 dBm power level to measure Power & EVM. Again this will sequential test, where DUT1 gets tested first followed by DUT2.

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  • \$\begingroup\$ It would depend on what tests and need for crosstalk rejection of leakage RF. Rx is likely ok but Tx would have to be Mux'd by some digital method. I presume you may have some self tests for Rx but Tx may need shared Analyzer for impedance, spectral response etc. \$\endgroup\$ – Sunnyskyguy EE75 Mar 6 '17 at 3:11
  • \$\begingroup\$ We could be able to help if your shared some additional information about your test setup, frequency bands, power levels and measurements to be done. \$\endgroup\$ – Enric Blanco Mar 6 '17 at 8:43
  • \$\begingroup\$ The setup is fairly straigh forward, VSG connected to 2 to 1 splitter/combiner OR SPDT switch which is connected to 2 DUTs. Its a 2.4/5 GHz 802.11 abgn signal, testing Rx signal at -70 dBm sensitivity and Tx signal at 20 dBm power level to measure Power & EVM. \$\endgroup\$ – eecs Mar 6 '17 at 15:22
  • \$\begingroup\$ I would imagine that acceptable loss from the signal generator to the DUT is specified by the relevant ETSI standard. Start there. \$\endgroup\$ – Lundin Mar 6 '17 at 15:58
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High isolation RF switches are expensive and mechanical switches have finite lifetimes. Also, there is the time involved in switching. If you can use a splitter, you avoid the limited lifetime and time delays.

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  • \$\begingroup\$ Thanks for the pros & cons. Any comments on accuracy wise? \$\endgroup\$ – eecs Mar 9 '17 at 6:30

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