Can mixers be used to upconvert?

[SPOORTHI GANGARAJ]

can mixers be used to upconvert 70Mhz frequency to 2040Mhz frequency?

 

[goldsmith]

Hey Dude!
Hi
Yes . it is possible. with mixers , you can multiply your frequency as well as . why you don't use a simple HF diode and tank circuit as multiplier?
Respect
Goldsmith

 

[SPOORTHI GANGARAJ]

hey i am doing a satellite project,so i need the mixer which can upconvert 70Mhz to 2040Mhz

---------- Post added at 18:55 ---------- Previous post was at 18:48 ----------

Hey Dude!
Hi
Yes . it is possible. with mixers , you can multiply your frequency as well as . why you don't use a simple HF diode and tank circuit as multiplier?
Respect
Goldsmith

do you the circuit for this mixer?

 

[goldsmith]

Again Hi
With EHF diodes you can do it as well as. or with EHF transistors.
you can find them simply !
Kind regards

 

[dick_freebird]

Sure, if you happen to have 1970MHz or 2110MHz laying about, and don't
mind the image tone 140MHz away (which at that frequency will not be
real easy to filter away, only 3% offset).

Think harder about what you are trying to do. Make a tone, or modulate?
Are you going to be criticized for spurious emissions later?

 

[enjunear]

can mixers be used to upconvert 70Mhz frequency to 2040Mhz frequency?

You probably want to do two up-mixes. If you go from 70 to 2040 directly, you could use an LO at (2040-70) or (2040+70), so 1970 or 2110 MHz, respectively. However, in the first case, you'll have the RF (desired) signal at 1970+70 (2040), and an image frequency at 1970-70 (1900). As Dick mentioned, this would be a real pain in the backside to filter off (very close-in).

Maybe think about mixing up to a UHF-band IF, say 730 MHz. If you start with 70, mix with 800, you'll get 730 and 870. That will be much easier to make a steep bandpass filter for. Then you can mix from 730 to 2040 using something like 1310 MHz. Then you'd have the RF at 1310+730 (2040) and an image at 1310-730 (580). All you'd need is a nice highpass filter to kill that image frequency.

You can play around with the mix products, picking the right pair is more of an art than a science. There are other things to consider, so be sure you're working with someone that's done a bunch of receiver design, if you have one in your company.

Don't forget to properly terminate the harmonics of the mixer with your filter... look at using a diplexer design (the fundamental frequency goes to one branch... on to the next RF stage, and the harmonics go down the other branch... to a 50 ohm termination resistor).

Lots of mixers to start looking at here:
RF Mixers / Multipliers | RF ICs | Analog Devices