Thank you for sharing your notes and talking through them. So many resources focus on the multitude of possible schematics that the details get disjointed across the entire piece of literature if they are included.
Hi, Mr. Sengupta. From what you've said at around 18:40 on the video, could you explain with some more detail what is the averaging of the signal from the LNA?
He doesn’t want the RF signal to appear at the output of the mixer, only the down converter frequency. It’s called double balanced because the differential switches will prevent the local oscillator’s frequency from appearing at the output while the cross coupled switches prevent the input RF frequency from going to the output. Balanced just means they have the same effect in both directions, so when the switches flip it’s like the same thing is happening twice in opposite direction i.e. averaging to zero.
Source is at Vcm gate is at either Vcm+VLO or Vcm, the former results in Vgs = VLO requires VLO to be larger than Vth of the gate for the switch to close while the latter results in Vgs = 0 meaning the switch is off if it is constructed out of enhancement mode devices.
Thank you for sharing your notes and talking through them. So many resources focus on the multitude of possible schematics that the details get disjointed across the entire piece of literature if they are included.
Best combination of theory and practical implementation. Please keep uploading videos like that.
Very nicely explained sir..
Great tutorial for anyone who needs reference on RFIC concepts
Hi, Mr. Sengupta. From what you've said at around 18:40 on the video, could you explain with some more detail what is the averaging of the signal from the LNA?
He doesn’t want the RF signal to appear at the output of the mixer, only the down converter frequency. It’s called double balanced because the differential switches will prevent the local oscillator’s frequency from appearing at the output while the cross coupled switches prevent the input RF frequency from going to the output. Balanced just means they have the same effect in both directions, so when the switches flip it’s like the same thing is happening twice in opposite direction i.e. averaging to zero.
24:23 don't quite understand, how Vcm+VLO comes to Vg when LO clock is high...
Source is at Vcm gate is at either Vcm+VLO or Vcm, the former results in Vgs = VLO requires VLO to be larger than Vth of the gate for the switch to close while the latter results in Vgs = 0 meaning the switch is off if it is constructed out of enhancement mode devices.
great video but the noise is unbearable