Title :
A 5 GHz-band SiGe-MMIC direct quadrature modulator using a doubly stacked polyphase filter
Author :
Nakajima, Kensuke ; Sugano, Takayuki ; Suematsu, Noriharu
Author_Institution :
Inf. Technol. & R&D Center, Mitsubishi Electr. Corp., Kanagawa, Japan
Abstract :
A 5 GHz-band SiGe-MMIC direct quadrature modulator using a doubly stacked polyphase filter (PPF) is described. The doubly stacked PPF can dramatically reduce the output phase and magnitude imbalance corresponding to the transmission line length inside the RC PPF networks. The quadrature modulator using two-stage doubly stacked PPF performs the error vector magnitude of 3.6 %rms, magnitude error of 3.0 %rms, and phase error of 1.2 deg at LO frequency of 5.8 GHz for π/4-shifted QPSK (2 Msps) modulated signals. Wideband characteristics from 5.0 to 6.5 GHz are also demonstrated. This modulator dissipates 11.3 mA at 3.3 V supply voltage.
Keywords :
Ge-Si alloys; MMIC; error analysis; microwave filters; quadrature amplitude modulation; quadrature phase shift keying; radio equipment; semiconductor materials; 11.3 mA; 3.3 V; 5 GHz; 5.0 to 6.5 GHz; 5.8 GHz; LO frequency; RC PPF networks; SiGe; SiGe-MMIC direct quadrature modulator; doubly stacked PPF; doubly stacked polyphase filter; error vector magnitude; magnitude error; output magnitude imbalance; output phase imbalance; phase error; quarter wave-shifted QPSK modulated signals; supply voltage; transmission line length; wideband characteristics; Costs; Distributed parameter circuits; Frequency; Information filtering; Information filters; Information technology; Insertion loss; Research and development; Transceivers; Transmission lines;
Conference_Titel :
Radio Frequency Integrated Circuits (RFIC) Symposium, 2004. Digest of Papers. 2004 IEEE
Print_ISBN :
0-7803-8333-8
DOI :
10.1109/RFIC.2004.1320637
