A low local input 1.9 GHz Si-bipolar quadrature modulator with no adjustment

Author

Otaka, Shoji ; Yamaji, Takafumi ; Fujimoto, Ryuichi ; Takahashi, Chikau ; Tanimoto, Hiroshi

Author_Institution

Res. & Dev. Center, Toshiba Corp., Kawasaki, Japan

Volume

31

Issue

1

fYear

1996

fDate

1/1/1996 12:00:00 AM

Firstpage

30

Lastpage

37

Abstract

A 1.9 GHz quadrature modulator with an onchip 90° phase-shifter was fabricated using a silicon bipolar technology. This paper investigates error factors caused by a limiter amplifier. It is found that a gain enhancement technique in a phase-shifter circuit is effective in realizing an adjustment free quadrature modulator; we propose a new high-gain phase shifter circuit for this purpose. This technique employs a current mode interface and an on-chip inductor. An image-rejection ratio of over 45 dBc and a carrier feedthrough of below -40 dBc were attained at -15 dBm local oscillator power. This quadrature modulator operates at 2.7 V supply voltage. The operating frequency ranges from 1.2 GHz to 2.3 GHz. The die size of the quadrature modulator IC is 2.49 mm×2.14 mm

Keywords

UHF integrated circuits; UHF phase shifters; bipolar analogue integrated circuits; elemental semiconductors; limiters; modulators; silicon; 1.2 to 2.3 GHz; 1.9 GHz; 2.7 V; 90° phase-shifter; Si; bipolar quadrature modulator; carrier feedthrough; current mode interface; die size; error factors; gain enhancement technique; image-rejection ratio; limiter amplifier; local oscillator power; operating frequency; phase-shifter circuit; Capacitors; Circuits; Energy consumption; Frequency; Inductors; Local oscillators; Mutual coupling; Phase modulation; Silicon; Voltage;

fLanguage

English

Journal_Title

Solid-State Circuits, IEEE Journal of

Publisher

ieee

ISSN

0018-9200

Type

jour

DOI

10.1109/4.485862

Filename

485862