Buffer for VCO at 2GHz

[moisiad]

Hi

I have designed an integrated VCO, operating at 1.5GHz with 1.2V. The VCO is capable of driving a capacitive load (up to 500f) and not a low resistance value (e.g 50 Ohm), since it is fabricated to drive the gates of a MOS mixer. The problem is that i want to measure it as a standalone circuit with a network analyser, which has one 50 Ohm port. Do you know any commercial buffer that can help to perform such a measurement. In fact the buffer should be suitable to operate up to 2GHz, has a high input resistance (>10KOhm) and adequately drive 50Ohm in the output.

Thanks

 

[BigBoss]

**broken link removed**

 

[radiohead]

You cannot measure a VCO with a network analyzer. You can test the spectrum with a spectrum analyzer.

In case you are interested in the phase noise at the fundamental you might consider sniffing the signal with a self made probe: A coax-line and a pigtail at the end connecting ground and signal conductor does the trick. Fix it mechanically around the oscillator and I'm sure you will pick up something big enough to measure the phase noise.