3 Summary

This application note presented the test results of how fast the user can switch the RF signal output from two LMX2820s with a RF switch in a ping-pong architecture. LMX2820 only takes 10 ns to mute or unmute, the overall switching time is basically determined by the RF switch. With the chosen RF switch for use in this application note, the switching time is around 40 ns, which is still much shorter than a typical VCO frequency switching time of a synthesizer.

When muted, LMX2820 leakage is about 50 dBc. The RF switch provides another 40 dB isolation, making the overall system isolation to around 90 dB.