CMOS Gm C IF Filter using Switch Capacitor Array SCA for dual band receiver

Abstract

In wireless communication system where it is necessary to control the bandwidth of the newlinesignal path, filters are frequency-selective electronic circuits designed to pass a band of newlinewanted signals and stop or reject unwanted signals, noise or interference outside the pass newlineband. The pass band of a filter is the range of frequencies over which signals are newlinetransmitted from input to output without attenuation or gain. For higher frequencies, newlinehowever, Operational amplifiers designs become difficult due to their frequency limit, so newlineat those high frequencies, operational transconductance amplifiers (OTAs) replace newlineoperational amplifier as the building blocks. Using OTAs as the building blocks for newlineanalog applications and scaling-down semiconductor technologies, OTAs can work up to newlineseveral hundred MHz. Currently, high frequency, high linearity, and low power are the newlinethree main concerns of CMOS OTAs. Tradeoffs have to be made among these aspects in newlinedesigning practical OTAs. Amongst all the topologies of OTA, on the basis of literature newlinesurvey, Folded Cascode OTA is chosen as it allows negligible swing limitations. newlineContinuous-time filters implemented with transconductance amplifiers and capacitors newlineknown as Gm-C Filter or OTA-C Filter. Rapidly growing mobile and wireless newlinecommunication market, fully integrated filters for very high frequency and low power newlineconsumption applications have received considerable attention. In most continuous-time newlinefilters, an on-chip automatic tuning system is incorporated to overcome performance newlinedegradation due to process variations and fabrication tolerances as well as the effects of newlineparasitic, temperature, and environment changes. newlineThis research work involve research studies to realize CMOS Folded Cascode OTA and newlineimplement on chip High frequency gm-C IF Filter for Dual Band FM band and GSM newlineband. An array of Band selection filters in a Multi Mode design is not power efficient and newlineit would occupy large chip area, so it is decided to realize single band select filter that newlinemeets the requireme