The Research And Design Of Current Differencing Transconductance Amplifier–based Field Reconfigurable Analog Array And Its Application On Filters And Oscillators

Because the current-mode circuits have the advantages of high speed,wide bandwidth,low power consumption and large dynamic range,and they develope rapidly in the past few decades.The current differencing transconductance amplifier(CDTA)is a really current-mode active block,unlike the conventional operational transconductance amplifier(OTA)and the second generation current conveyor(CCII),the inputs and outputs of the CDTA are all currents,and the CDTAs are widely used in designing current-mode filters,oscillators and various of analog signal processing circuits.The Field Programmable Analogue Array(FPAA)could achieve a variety of analog signal processing circuits by turning on and off the programmable switches.The FPAAs are environmentally-adapted circuits,and they have a wide range of applications.The CDTA-based FPAA has the advantages of lower input impedence,higher output impedence,lower transmission loss,and it is a kind of good performance FPAA.The CDTA-based butterfly-shaped FPAA is deeply studied,and the CDTA-based filters and oscillators which can also be generated by this butterfly-shaped FPAA are detailedly discussed in this thesis.The main innovations of this thesis can be summarized as follows:(1)A novel CDTA-based butterfly-shaped FPAA is proposed.Firstly,a NMOS-based lwo voltage low power CDTA with transconductance linearly tuneable is proposed in this thesis.Based on the NMOS-CDTA,a novel configurable analogue block(CAB)is designed,and using the NMOS-CDTA-based CAB,a butterfly-shaped continuous-time FPAA is realized.In order to reduce the number of CABs used in the FPAA,the butterfly-shaped is adopted.There are only six CABs used in the proposed FPAA,and the CABs in the FPAA are connected by meshed vertical input lines and horizontal output lines,and each node of the mesh is connected by a programmable switch.The proposed FPAA is realized using Charted 0.18?m CMOS process,and the measured results show that the proposed FPAA could successively provide the following five basic analog circuit functions: six order current-mode low pass filter,second order current-mode universal filter,current-mode quadrature oscillator,current-mode multi-phase oscillator and current-mode multiplier.Moreover,the bandwidth of the generated six order current-mode low pass filter is 200 MHz,the oscillation frequency of the generated current-mode quadrature oscillator is 76 MHz,and the oscillation frequency of the generated current-mode multi-phase oscillator is 11.7MHz.(2)A CDTA-based sigle-input multi-output(SIMO)filter and a CDTA-based multi-input single-output(MISO)filter are proposed.The two proposed filters can all be generated by the butterfly-shaped FPAA,and they have the advantages of fewer active and passive devices,and they can realize low-pass,high-pass,band-pass,band-stop and all-pass filter functions.Moreover,the characteristic parameters ?o and Q of the two filters can be orthogonally tunable,and they are suitable for active filter applications.The two filters are verifid by using Pspice with Charted 0.35?m CMOS process,and the simulated results show that the working frequencies of the two filters are 6MHz and 10 MHz,respectively.Each filter only consists of two CDTA and two grounded capacitors,and they could realize the basic five filtering functions.(3)Several CDTA-based second-order and third-order quadrature oscillators are presented.The proposed oscillators can also be generated by the butterfly-shaped FPAA,and they only consist of CDTAs and grounded capacitors,each oscillator could provide two or four quadrature output signals.The proposed oscillators are verified by using Cadence IC tools with Charted 0.18?m CMOS process,and the simulation results show that the oscillation frequencies of the two third-order quadrature oscillators are 145.14 MHz and 63.68 MHz,respectively.Moreover,the oscillation condition and oscillator frequency of each oscillator can be independently adjusted,and all the proposed oscillators can be used as variable frequency oscillators.(4)The simplified CDTA for high frequency applications is designd in this thesis.Based on the simplified CDTA,a programmable muti-phase RF oscillator is proposed.The proposed programmable muti-phase RF oscillator could provide six or eight sinusoidal signals,and the CDTA-based low frequency oscillation theory is applied to high frequency oscillation design.The post-layout simulation results show that the supply voltage of the muti-phase RF oscillator is only 1V,and the simulated oscillation frequency of the six-phase oscillator is 1.45 GHz,its oscillation frequency can be tuned from 788.5MHz to 2.506 GHz,and the frequency tuning range is 1.7GHz;the simulated oscillation frequency of the eight-phase oscillator is 1GHz,its oscillation frequency can be tuned from 558.9MHz to 1.512 GHz,and the frequency tuning range is 0.95 GHz.Moreover,according to the theory of the CDTA used in signal processing circuits,an amplifier-based 2.4GHz low voltage low power and high voltage gain mixer for ISM band application is presented in this thesis.