Title :
A switched-capacitor image rejection filter, for complex IF receivers
Author :
Pun, Kong-Pang ; Franca, José E. ; Azeredo-Leme, C.
Author_Institution :
Centre for Microsyst., Inst. Superior Tecnico, Lisbon, Portugal
Abstract :
This paper presents a switched-capacitor (SC) image rejection filter to solve the image problem in complex IF receivers, caused by mismatches between the in-phase (I) and quadrature (Q) paths. The proposed filter is actually a complex FIR Hilbert transformer with a notch frequency at +¼fs, (fs is the sampling frequency). An SC realization, as a part of the sampling units of the analog-to-digital convertor (ADC), is proposed. As demonstrated by circuit simulations, over 70 dB of image rejection can be achieved in the presence of 1% capacitance mismatch
Keywords :
FIR filters; Hilbert transforms; analogue-digital conversion; circuit simulation; digital radio; radio receivers; switched capacitor filters; SC realization; analog-to-digital convertor; capacitance mismatch; circuit simulations; complex FIR Hilbert transformer; complex IF receivers; mismatches; notch frequency; sampling frequency; sampling units; switched-capacitor image rejection filter; 1f noise; Circuit simulation; Costs; Digital communication; Finite impulse response filter; Frequency; Image converters; Image sampling; Local oscillators; Receivers;
Conference_Titel :
Circuits and Systems, 2000. IEEE APCCAS 2000. The 2000 IEEE Asia-Pacific Conference on
Conference_Location :
Tianjin
Print_ISBN :
0-7803-6253-5
DOI :
10.1109/APCCAS.2000.913426
