i am design an up conversion mixer in TX , but the IF power is saturating the mixer in my design , when i use 0 dbm as the IF input , i found that the output power is about -6 dbm
but when i just made the input power -30 dbm IF , i found the upcomverter singal have about -18 dbm , this means i have about 12 db gain
i need to make the mixer work in 0 dbm , any recommendations
you have voltage gain more than 3dB, so you must use gilbert cell.
Assume you use CMOS transistor
In case the IF signal is so large that makes the input transistor works in linear region instead of in saturation region, I think you should decrease the load resistor and increase the transconductance gm.
have you tried the resistive fet mixer yet? I've seen compression points at least in this ballpark at this frequency range using the NE32/4210 devices.
Why don't you use a Hittite mixer? hmc219ms8.pdf has a typical input referred 1 dB compression point of 10 dBm. I would certainly advise a passive mixer for better linearity.
i need to design a dual band mixer (GSM - 900 MHz and 1800MHz). i used a dual band hybrid coupler in ADS, converted this layout in to schematic and added diodes.My desired IF is 500MHz.I designed a filter for tht frequency also.Now my problem is i dont know how to give inputs(RF and LO) and to which ports of Hybrid coupler in ADS.dont know how to use tht sweep plan. can anybody suggest me the solutions....
Maybe you can using DESIGN GUIDES,that have some sample can be pratices.
I'd ever using transistor design UP-converter.
maybe you can using BFT25 transistor, good luck