Measure Return Loss of Mixer LO port

[TXRX]

Hi,

I wand to desigh a matching circuit to the Mixer LO Port.

I have VNA HP 8720B (2-port), Do you have any idea how to measure the Return Loss of only the LO Port of the Mixer ?

TXRX

 

[kh4n]

calibrate vna
terminate rf and if ports
turn on supply voltages, if mixer needs any
connect lo port to any vna port
and measure

 

[TXRX]

Hi kh4n,

But the maximum power from the VNA is -10dBm and i want to measure the return loss at LO= +7dBm.

 

[kh4n]

thats a different case, i did not measure before but
maybe signal source, amp, att, coupler to measure incident and reflected power , power meter might help

 

[BigBoss]

LO Return Loss is not a very significant measure.Because LO port is a "hard drivien" port and this LO signal will drive your mixer-either diode or transistor- to switch the commutating components and Retrun Loss has less importance.However, VNA's have generally +13dBm output power but if yours doesn't, simply amplify it but you can not measure accurately Return Loss because Output Return Loss of your amplifier will serve as your source and calibration wouldn't work since if you can find an ideal like amplifier.