Is there challenges in RF application under 600MHz ?

There are the same challenges as in RF design above 600 MHz. Designing and building a device that meets the specifications, at an appropriate cost, that is manufacturable in quantity.

Making things small is a bit of an issue, since component values tend to be larger, especially inductors. Embedded transmission lines become a problem because they become long. Antenna's become larger. Power levels become larger because cellular/mesh systems are not as prevalant, and point to point networks are widely used.

Dave
www.keystoneradio.com

Many of the challenges at lower frequencies are non-communications applications.
There are systems in the tens and hundreds of KW and higher that are tough to design, require fast tuning and sophisticated control but whose end results are induction heating parts on the inside of non-metalic barriers, or dielectric heating of uneven materials on a belt travelling at high speeds, or in sputtering or other particle application.

I have CMOS 1μm technology, I'm looking for Rf applications with this technology

Hi

What do you think about Power amplifiers under 600MHz ?