Quadrature Modulator design [hlp]

Hello Everyone;
How I can design a quadrature modulator with wideband I & Q inputs and a constant frequency LO? I want to have very good sideband suppression.

Key to having good sideband suppression is keeping the imbalance under control.

Analog IQ modulators come in different kinds, but generally the rule is that the higher the carrier freq is, the more imbalance you will get. Therefore it is better to modulate at lower freqs and upconvert.

On-chip this architecture stinks because steep off-chip filters are required. Ofter a baseband modulator is used and the imbalance is compensated through other techniques like DSP.

The best sideband suppression can be reached by using digital upconverters. The performance is very good, but it sinks loads of power. But probably you'll need that anyway for proper broadband operation.

How do you intend to generate the quadrature LO?