Question on Y-factor measurement on mixers NF

[Rainleo]

y factor to measure nf

I am performing a measurement of NF on my mixer, using the Y-factor method. Could someone please explain to me my results is single-sideband or double sideband? Thanks.

 

[RF-OM]

y factor dsb

I am not sure I understood your question correctly. SSB and DSB noise differ 3 dB. If you need help with Y-method I include two papers about this method. Definitely they may be helpful for noise measurement.

Best regards,
RF-OM

 

[Rainleo]

nf measurement y factor example

Thanks for the reply. My question is, for example, I use Y-factor to measure the noise figure of my mixer, and I got my noise figure from NF=ENR/(Y-1) is 6dB. 6dB is DSB NF or SSB NF ?
I am a little bit confused on this.

 

[RF-OM]

y factor , noise measurement

Now it is more clear. If you do not use filter at the mixer output it means you are measuring DSB. When you use the filter to remove one of the side bands you have the SSB signal. In this case you are measuring LSB or USB, depends on which SB you are filtering out.

 

[Rainleo]

I will put a notch filter and do the measurement on Monday.
Thx...

 

[RF-OM]

Are you sure about notch filter? Usually band-pass filter used to chose one of the sidebands. Notch filter you need when it is necessary to suppress some part of the spectrum but pass all other frequencies. For example when you need to additionally suppress the carrier.

BR,
RF-OM

 

[Rainleo]

I am thinking about notch out either USB or LSB to see the SSB noise figure. Bandpass is good also.

 

[RF-OM]

I think you understanding of this problem is right and in this case it is not a big difference what king of filtering you are using if filter properties are matching your goal.

BR,
RF-OM