Title :
Analysis of Direct-Conversion IQ Transmitters With 25% Duty-Cycle Passive Mixers
Author :
Mirzaei, Abdolreza ; Murphy, Damian ; Darabi, Hooman
Author_Institution :
Broadcom Corp., Irvine, CA, USA
Abstract :
The performance of direct-conversion IQ transmitters with 25% duty-cycle passive mixers is analyzed. The up-conversion transfer function is calculated and it is shown that due to lack of reverse isolation of the passive mixer, the high- and low-side conversion gains can be different. The contribution of thermal noise from mixer switches to the total output noise of the transmitter is formulated. It is also revealed that the up-conversion of the baseband signal to higher order harmonics places more stringent linearity requirements on the post-mixer driver.
Keywords :
mixers (circuits); switches; thermal noise; transfer functions; transmitters; baseband signal; direct-conversion IQ transmitter analysis; duty-cycle passive mixers; higher order harmonics; low-side conversion gains; mixer switches; post-mixer driver; thermal noise; up-conversion transfer function; Baseband; Harmonic analysis; Mixers; Noise; Radio frequency; Transfer functions; Transmitters; 25% duty-cycle; Direct-conversion; linearity; noise; passive mixer; transfer function; transmitter;
Journal_Title :
Circuits and Systems I: Regular Papers, IEEE Transactions on
DOI :
10.1109/TCSI.2011.2142790
