Title :
A compact mixer and DAC for implementation of a direct conversion OQPSK transmitter
Author :
Chahardori, Mohammad ; Mehrmanesh, Saeid ; Zamanlooy, Babak ; Atarodi, Mojtaba
Author_Institution :
Microelectron. Res. & Dev. Centre, Tehran
fDate :
Oct. 30 2007-Nov. 2 2007
Abstract :
A compact low power circuit for implementation of a direct conversion OQPSK modulator is proposed. The circuit consists of a digital to analog converter, a low pass filter and an up-converter mixer. By embedding these three blocks, the circuit performance is enhanced and the total power consumption is reduced. The mixer is designed base on a Gilbert cell with on chip inductor loads. Instead of transconductance transistors of Gilbert cell, a fully deferential current mode DAC is used and proficiently a low pass filter is embedded between them and therefore the linearity of total system is improved. All of circuits are designed based on 0.18 mum CMOS technology with a single 1.8 volt power supply.
Keywords :
CMOS integrated circuits; digital-analogue conversion; integrated circuit design; low-pass filters; low-power electronics; mixers (circuits); modulators; quadrature phase shift keying; radio transmitters; radiofrequency integrated circuits; CMOS technology; Gilbert cell; chip inductor; current mode DAC; digital-to-analog converter; direct conversion OQPSK modulator; low pass filter; low-power circuit; power consumption; size 0.18 mum; up-converter mixer; voltage 1.8 V; CMOS technology; Circuit optimization; Digital-analog conversion; Energy consumption; Inductors; Linearity; Low pass filters; Power supplies; Transconductance; Transmitters; Digital to Analog; Gilbert cell; Low-Pass Filter; OQPSK modulator; Up-converter Mixer;
Conference_Titel :
TENCON 2007 - 2007 IEEE Region 10 Conference
Conference_Location :
Taipei
Print_ISBN :
978-1-4244-1272-3
Electronic_ISBN :
978-1-4244-1272-3
DOI :
10.1109/TENCON.2007.4429101
