Continuous-Time Low-Pass Filters for Integrated Wideband Radio Receivers

Abstract

This thesis concentrates on the design and implementation of analog baseband continuoustime low-pass filters for integrated wideband radio receivers. A total of five experimental analog baseband low-pass filter circuits were designed and implemented as a part of five single-chip radio receivers in this work. After the motivation for the research work presented in this thesis has been introduced, an overview of analog baseband filters in radio receivers is given first. In addition, a review of the three receiver architectures and the three wireless applications that are adopted in the experimental work of this thesis is presented. The relationship between the integrator nonidealities and integrator Q-factor, as well as the effect of the integrator Q-factor on the filter frequency response, are thoroughly studied on the basis of a literature review. The theoretical study that is provided is essential for the gm-C filter synthesis with non-ideal lossy integrators that is presented after the introduction of different techniques to realize integrator-based continuous-time low-pass filters. The filter design approach proposed for gm-C filters is original work and one of the main points in this thesis, in addition to the experimental IC implementations. Two evolution versions of fourth-order 10-MHz opamp-RC low-pass filters designed and implemented for two multicarrier WCDMA base-station receivers in a 0.25-um SiGe BiCMOS technology are presented, along with the experimental results of both the low-pass filters and the corresponding radio receivers. The circuit techniques that were used in the three gm-C filter implementations of this work are described and a common-mode induced even-order distortion in a pseudo-differential filter is analyzed. Two evolution versions of fifth-order 240-MHz gm-C low-pass filters that were designed and implemented for two single-chip WiMedia UWB direct-conversion receivers in a standard 0.13-um and 65-nm CMOS technology, respectively, are presented, along with the experimental results of both the lowpass filters and the second receiver version. The second UWB filter design was also embedded with an ADC into the baseband of a 60-GHz 65-nm CMOS radio receiver. In addition, a thirdorder 1-GHz gm-C low-pass filter was designed, rather as a test structure, for the same receiver. The experimental results of the receiver and the third gm-C filter implementation are presented.Keywords Analog integrated circuits, CMOS, continuous-time filters, radio receivers Tiivistelmä Tässä väitöskirjassa on tutkittu analogisten kantataajuisten jatkuva-aikaisten alipäästö-suodattimien toteutusta integroituihin laajakaistaisiin radiovastaanottimiin. Työssä on suunniteltu ja toteutettu yhteensä viisi analogista kantataajuista alipäästösuodatinpiiriä viiteen yhdelle puolijohdepalalle integroituun radiovastaanottimeen. Väitöskirjan alussa esitetään tutkimustyön taustoja, jonka jälkeen luodaan yleiskatsaus analogisiin kantataajuussuodattimiin osana radiovastaanotinta. Lisäksi tarkastellaan niitä kolmea vast...

New systematic two‐graph‐based approach of active filters employing multiple output current controlled conveyors

“…Nowadays, active filters are an unavoidable component in analogue circuit design. In high-order active filter design, two methods are mostly used: building high-order filters by cascading second-or first-order filters [1,2] and using passive LC ladder prototype [3][4][5]. Among these methods, the cascading-based approach is not low-sensitive, but the passive LC ladder-based method offers a low-sensitive approach [1].…”