Title :
Balanced MMIC QPSK modulator with low amplitude and phase errors
Author :
Seong-Mo Moon ; Han Lim Lee ; Dong-Hwan Shin ; In-Bok Yom ; Moon-Que Lee
Author_Institution :
Satellite & Wireless RF Technol. Res. Sect., ETRI, Daejeon, South Korea
Abstract :
A broadband monolithic microwave integrated circuit (MMIC) quadrature phase shift keying (QPSK) modulator with low amplitude and phase errors is proposed. The presented modulator adopts two wideband reflection-type binary BPSK modulators, each consisting of a modified Lange coupler with additional λ/4 transmission lines, varactor diodes, inductors and resistors. The proposed QPSK modulator is implemented in 0.15 μm GaAs low-noise pHEMT process. The measurements show an error vector magnitude and a demodulated I/Q offset <;5.8% root-mean-square and -16.1 dB, respectively, from 18 to 26.5 GHz.
Keywords :
III-V semiconductors; MMIC; gallium arsenide; high electron mobility transistors; microwave field effect transistors; modulators; quadrature phase shift keying; semiconductor device measurement; BPSK modulator; EVM; GaAs; RMS; additional λ/4 transmission line; amplitude error; balanced MMIC QPSK modulator; broadband MMIC quadrature phase shift keying modulator; demodulated I-Q offset; error vector magnitude; frequency 18 GHz to 26.5 GHz; gain -16.1 dB; inductor; low-noise p high electron mobility transistor process; modified Lange coupler; pHEMT process; phase error; resistor; root-mean-square; varactor diode;
Journal_Title :
Electronics Letters
DOI :
10.1049/el.2013.2444
