フリップ・フロップ型90°移相器を適用したデュアルLOスイッチング型直交変調器の設計

抄録

In recent years, the number of mobile wireless devices that use the modulation such as QAM is increased, and it requires high-precision quadrature modulators and low-cost circuits composed of CMOS devices. In this paper, we propose a quadrature modulator, composed of a newly configured quadrature mixer with function to correct the phase error of LO signal, a flip-flop frequency divider for quadrature LO generation, and an RC-polyphase filter for delay correction. Moreover, we reveal that this circuit has compensation mechanism for the duty-cycle-error of the frequency-doubled-LO (2LO) input signal.