Quadrature Modulation Using Radio Frequency Wave Correlation In Multiport Network

Abstract

This paper presents design and implementation of radio frequency quadrature modulator using multi-port network. The modulator utilizes Schottky diodes as high-speed variable impedance loads controlled by baseband data. The reflection coefficients produced by these variable loads modulate the RF carrier in proportion to the baseband signals. The paper also demonstrates test bed for generating differential in-phase and quadrature-phase baseband signals corresponding to digital modulation scheme. The hardware is designed and fabricated for operating at center frequency of 2 GHz. The results show successful modulation of 20 MHz LTE signal using 16 QAM data.