filters to remove VCO harmonics?

Is there any small filters commercially available (under 3GHZ range) for remove VCO harmonics?

how do you do it?

http://www.microwavefilter.com/LPmicrominiature.htm
http://www.minicircuits.com/pdfs/LFCN-6000.pdf

AVX, Murata, Toko, ...
Many manufacturers produce low pass filters in very small SMD packages..

except minicircuits ,others give small size filters only for ISM bands.

I tested Minicircuits LFCN ,at stop band as its datasheet said it gives 30 db attenuation to me, I cascaded another one of this filters(seri) to get more attenuation but it does not give more attenuation,why? Is there a way to get more than 30 db atten. for harmonics ?

The harmonic level relative to main signal is -50dB ,Is this good for LO of a mixer?