A current-mode RF transmitter for 6-9 GHz MB-OFDM UWB application
This paper presents a current-mode 6-9 GHz RF transmitter for MB-OFDM UWB systems. The proposed current-mode transmitter consists of current-mode IQ LPF, current mirror amplifier, IQ up-conversion mixer (up-mixer), differential power driver amplifier (PA) and high-speed divider with LO buffers for generating IQ LO signals. All circuits are designed to possess high linearity and wide bandwidth. The transmitter is fabricated in TSMC 0.13 mu m 1P8M RF CMOS technology with a die area of 1.56 mm(2). Measurement results show that a maximum output power of -0.7 dBm with an LO leakage/sideband rejection ratio (LOL/SB RR) around -33/-35 dBc is achieved, and that this transmitter excels the traditional voltage-mode counterpart in terms of high linearity (about +1 dBm output 1-dB compression point, +10 dBm output IP3 in average) with comparable power consumption (drawing 48 mA current from 1.2 V supply).
current-mode rf transmitter mb-ofdm uwb high linearity cmos high speed divider