Comparative Analysis of Broadband Quadrature Modulator and Demodulator Parameters Digital Adjustment in Simulation and Measurements

Modulators and demodulators are devices that transmit information wirelessly. Quadrature modulation and demodulation are used to improve the transmission of information. The quadrature method makes it possible to achieve a significant sideband suppression. In addition to sideband suppression, gain, linearity, consumption, and quadrature mismatch are important parameters. To control them, an integrated digital adjustment is introduced into the circuit. The article presents the results of the design of a quadrature modulator and demodulator with built-in digital control of parameters for operation in the frequency range from 1.8 GHz to 6 GHz. The circuits are made in SiGe BiCMOS process and measured on equipment in the temperature range from -60 to +85 degrees. A comparison of the results obtained in the simulation and in the experiments was carried out. The digital adjustment use effectiveness has been proven.