Research and Development of Wideband Quadrature Signal Generator

The article presents the development of a broadband quadrature signal generator (QSG) from 10 MHz to 6 GHz. When designing the QSG in broadband of frequencies, there are some difficulties when using SiGe BiCMOS technology. The problems of linearity and broadband matching are most challenging to solve when using traditional solutions: using a polyphase filter or a digital D-trigger. The article presents a structure that allows you to develop a broadband quadrature signal generator with a range of operating frequency from 10 MHz to 6 GHz, using the method of dividing the operating frequency band. At frequencies from 1 to 6 GHz, the quadrature signal is generated using a polyphase filter, and at frequencies less than 1 GHz using a frequency divider. It is shown that using this method, and the following characteristics QSG are achieved: the difference in the amplitudes of quadrature signals is less than 0.3 dB; the SWR is less than 1.6 in the entire frequency range; the transmission coefficient is not less than -2 dB with a 0 dBm heterodyne power; at a frequency of 6 GHz, P1dB is not less than three dBm. The experimental results are in good agreement with the simulation data.