Title :
A 1.9-GHz-band GaAs direct-quadrature modulator IC with a phase shifter
Author :
Yamamoto, Kazuya ; Maemura, Kosei ; Andoh, Naoto ; Mitsui, Yasuo
Author_Institution :
Mitsubishi Electric Corp., Hyogo, Japan
fDate :
10/1/1993 12:00:00 AM
Abstract :
A 1.9-GHz-band direct-quadrature modulator IC has been successfully developed for digital portable telephone use. In the 1.9-GHz high-frequency band, both image and carrier rejections as low as -40 dBc have been obtained with a low-power dissipation of 110 mW at a single power supply of 3.1 V, corresponding to a phase error below 1.1. In order to reduce undesired sideband spectral components required for digital modulation, a newly developed circuit configuration that combines a quadrature phase shifter with drivers for amplitude imbalance compensation and makes spectrum efficiency and low-power dissipation possible is used. The modulator IC may be used in enhanced digital mobile radiocommunication systems such as digital portable telephones
Keywords :
III-V semiconductors; MMIC; digital radio systems; field effect integrated circuits; gallium arsenide; mobile radio systems; modulators; phase shifters; radiotelephony; 1.9 GHz; 110 mW; 3.1 V; GaAs; UHF; amplitude imbalance compensation; digital mobile radiocommunication systems; digital modulation; digital portable telephone; direct-quadrature modulator IC; drivers; low-power dissipation; phase shifter; single power supply; Amplitude modulation; Digital integrated circuits; Digital modulation; Frequency conversion; Gallium arsenide; Land mobile radio; Phase modulation; Phase shifters; Power dissipation; Telephony;
Journal_Title :
Solid-State Circuits, IEEE Journal of
