Problem in generating IF using SA612A mixer

sanketpatel2020 — Tue, 26 Jul 2016 05:39:37 GMT

Hi! Greetings!

I am new to NXP community. I have started working on SA612A mixer. Since few days, I have been struggling in generating IF (KHz) output.

NXP SA612A pin description (A quick reference so that you don't have to refer to the datasheet):

Pin1,2: differential RF input pins

Pin3: Ground

Pin4,5: differential IF output pins

Pin6,7: LO differential input

Pin8: +5V

My circuit configuration and problem detail:

44.94MHz RF applied to pin1 through DC blocking capacitor. Pin2 is grounded via capacitor. RF signal level on pin1 is: <-15dBm (200mV peak to peak into 1.5kOhm input resistance of SA612) (<-15dBm ensures linear operating range considering IIP3)
44.88MHz LO applied to pin 6, pin7 left open as suggested in datasheet/ application note:AN1993. LO level on pin6 is: 230mV peak to peak (as per datasheet, it has to be 200mV to 300mV peak to peak)
Expecting to see 60Kz output (difference frequency) peak in the spectrum analyzer.

60KHz signal seems totally immersed in the noise, not a peak at all, what can be the reason? Tried with other frequencies as well.

Please share your views on this.

Regards,

Sanket

Wireless MCUのトピックProblem in generating IF using SA612A mixer