A notch filter alignment circuit for wireless communication FDD systems

Author

Bormann, Dirk ; Frischen, Andreas R. ; Schrey, Moritz ; Kaehlert, Stefan ; Wunderlich, Ralf ; Heinen, Stefan

Author_Institution

Integrated Analog Circuits & RF Syst., RWTH Aachen Univ., Aachen, Germany

fYear

2010

fDate

7-10 Dec. 2010

Firstpage

1308

Lastpage

1311

Abstract

In this paper a circuit is presented that is capable to measure the transfer function of a notch filter as it could be used in modern wireless FDD systems like LTE and UMTS. As in FDD systems the TX PLL is always running during signal reception, its output is used to downconvert the TX leakage voltage after the notch filter to DC. A logarithmic amplifier boosts the dynamic range of the system to 30 dB. The whole system consumes less than 1 mA from a 1.4 V supply which is compensated for by the selectivity gain of the better adjusted notch filter. The circuit has been simulated on a 90 nm commercial technology.

Keywords

frequency division multiplexing; mobile radio; notch filters; transfer functions; TX leakage voltage; logarithmic amplifier; mobile wireless device; notch filter alignment circuit; size 90 nm; transfer function; voltage 1.4 V; wireless communication FDD system; Calibration; Dynamic range; Gain; Mixers; Production; Receivers; Tuning; Calibration; Circuit tuning; Notch filters; Q factor; tunable filters;

fLanguage

English

Publisher

ieee

Conference_Titel

Microwave Conference Proceedings (APMC), 2010 Asia-Pacific

Conference_Location

Yokohama

Print_ISBN

978-1-4244-7590-2

Electronic_ISBN

978-1-902339-22-2

Type

conf

Filename

5728502