Multi-band quadrature generator based on the virtual LO phase shifting technique

The paper describes a new digitally programmable multi-band precise quadrature generator. The proposed approach leads to high-phase resolution joint to uniform performances in all the sub-bands of synthesis. It is easily scalable in frequency and suitable to implement any calibration technique to compensate the typical phase imbalance generated in the front end. The theory governing the quadrature generation and the operation of the used multi-band VCO are described. A prototype reporting a phase error less than 0.5° over the two sub-bands confirming the architecture capabilities is finally reported.