Publications (7)0 Total impact

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    ABSTRACT: A flexible multimode receiver architecture for software defined radio systems with focus on GSM, WCDMA and CDMA systems has been designed in a 120 nm CMOS technology. The receiver consists of a wideband coilless common gate LNA2 with gain switches and a high linearity down-converter with current interface between mixer and baseband-filter. The LO signal of a 8 GHz VCO and divider with ratio 4 respectively 8 covers the whole receiver frequency range. The receiver consumes 32 mA at 1.5 V supply voltage
    Wireless Technology, 2006. The 9th European Conference on; 10/2006
  • Soeren R. Sappok · Andreas Neyer · Andre Kruth
    Proceedings of the Third IASTED International Conference on Circuits, Signals, and Systems, Marina del Rey, CA, USA, October 24-26, 2005; 01/2005
  • G. Ordu · A. Kruth · S. Sappok · R. Wunderlich · S. Heinen
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    ABSTRACT: An analog quadricorrelator demodulator is presented. The short introduction to this demodulator is followed by a discussion about the important DC offsets question. To eliminate this, co-channel performance degrading aspect switches are added to the quadricorrelator architecture. System simulation results show how robust the demodulator becomes with this small modification to the structure.
    Radio Frequency Integrated Circuits (RFIC) Symposium, 2004. Digest of Papers. 2004 IEEE; 07/2004
  • S. Sappok · A. Kruth · G. Ordu · R. Wunderlich · S. Heinen
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    ABSTRACT: A new straightforward ΣΔ-fractional-N modulation-loop design methodology is proposed in this paper. In contrast to present design approaches the closed loop transfer function can be used for pulse forming. An algorithm is presented which allows loop filter design based on the desired transfer function shaping. Using this technique, a closed loop modulation with low reference frequency for Bluetooth can be achieved without the need for predistortion. Using a 5<sup>th</sup> order loop filter, the ΣΔ modulator of order three will maintain the required noise specifications for the commonly used 13 MHz reference frequency. The resulting simulated total phase noise is as low as -111 dBc/Hz at 1.5 MHz and -132 dBc/Hz at 2.5 MHz.
    Circuits and Systems, 2004. ISCAS '04. Proceedings of the 2004 International Symposium on; 06/2004
  • 01/2004
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    ABSTRACT: A reconflgurable, difierentially driven sym- metric inductor is presented. This inductor is used in a difierential LC-VCO, which is implemented in a 0.35 "m SiGe-BiCMOS-process. The output frequency of the LC-VCO covers twice the frequencies of the DECT- and the ISM-band (3.76 GHz:::3.86 GHz respectively 4.8 GHz:::4.967 GHz). The maximum simulated Q- factor of the inductor at difierential excitation is about 10 at 3.86 GHz for the low frequency range and about 5.8 at 4.967 GHz for the high frequency range. The simu- lated phase noise of the difierential VCO is ¡137 dBc=Hz at 6.4 MHz ofiset for the low frequency band and ¡119 dBc=Hz at 2.5 MHz ofiset for the high frequency band. For both frequency ranges the VCO consumes a sup- ply current of 3.3 mA at a 3.3 V power supply voltage.
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    ABSTRACT: In this paper, the basics of the three major satellite navigation systems (GPS, GLONASS and GALI- LEO) are explained. They are analysed regarding their RF- frequency usage and a specification for the receiver's local oscillator is derived. Different oscillator topologies are inve- stigated to find a topology which satisfies the demands for a reception of all possible systems with a very low power con- sumption. Global Navigation Satellite Systems are based on mea- surements of distances from the receiver's position on earth to satellites in orbit. These satellites are on non-geo- stationary orbits, which means that they do not have a fixed position in relation to the earth's center. The measured di- stance is called "pseudo-range". These pseudo-ranges are determined by measuring the time which a transmitted si- gnal from the satellite needs to reach the receiver. In first approximation this equals the distance divided by light speed. Four pseudo ranges are necessary to calculate the receiver's position in three-dimensional space. To distin- guish between the received signals for each visible satel- lite, different methods are used in the three major satellite navigation systems. These are the the American GPS, the Russian GLONASS and the European GALILEO.