A Low-Voltage CMOS Current Mode Integrated Transmitter Front-end for 2.4-GHz Wireless Communications

Abstract

This paper presents a low-voltage low-power current mode transmitter front-end for 2.4 GHz wireless communication applications, which is fabricated in a chartered 0.18-mm CMOS technology. The direct up-conversion is implemented with a current mode mixer employing a novel input driver stage, which can significantly improve the linearity and consume a small amount of DC current. The driver amplifier utilizes a transimpedance amplifier as the first stage and employs an inter-stage capacitive cross-coupling technique which enhances the power conversion gain as well as high linearity. The measured results show that at 2.4GHz, the transmitter front-end provides 15.5dB of power conversion gain, output P-1dB of 3dBm, and the output-referred third-order intercept point (OIP3) of 13.8dBm, while drawing only 6 mA from the transmitter front-end under a supply voltage of 1.2 V. The chip area including testing pads is only 0.9 mm 1.1 mm. Index Terms –CMOS, up-conversion mixer, driver amplifier, transmitter, current mode, high linearity, low-power