This paper presents a current mode full-wave rectifier based on single modified Z copy current difference transconductance amplifier (MZC-CDTA) and two switches. The circuit is simple and is suitable for IC implementation. The functionality of the circuit is verified with SPICE simulation using 0.35？μm TSMC CMOS technology parameters. 1. Introduction The full-wave rectifiers are used in varied applications [5–8] such as signal-polarity detectors, averaging circuits, peak value detectors, clipper circuits, and amplitude-modulated signal detectors. Conventionally, full-wave rectifier is implemented using operational amplifiers which are not capable of operating at higher frequencies because of slew rate and fixed gain-bandwidth product limitations [9]. Current mode approach due to its inherent wide bandwidth which is virtually independent of closed loop gain, greater linearity, and large dynamic range [9] has generated lots of interest, and significant research efforts have been directed towards developing new active blocks based on this approach. Among these blocks, CDTA [10–12] has received considerable attention as the external resistors may be implemented by TA block of CDTA, thereby reducing/avoiding external resistors usage in the applications based on CDTA [12] and making these suitable for on-chip implementation. Additionally, due to low input impedance terminals, CDTA is free from parasitic capacitances and hence is appropriate for high frequency operation. This has resulted in development of a wide range of CDTA-based applications [1–4, 11–17]. A variety of FWR circuits using CDTA [1–4] have been reported in the literature. The CDTA-based FWR circuits presented in [1–3] use single CDTA, whereas configuration reported in [4] employs two CDTAs and a multiple output current follower. The structures [1, 2, 4] use four pn junction diodes, whereas two Schottky diodes are used in [3]. Additionally, auxiliary bias is employed in [1] and a grounded resistor is employed in [4]. In this paper, a new approach for designing a single CDTA-based current mode full-wave rectifier (FWR) configuration is presented. The proposed current mode FWR configuration uses a single CDTA called MZC-CDTA (modified Z copy CDTA) and two MOS switches. The features of the CDTA-based FWR circuits are summarized in Table 1. It may be noted that the proposed FWR uses similar a number of active elements as given in [3]; however, the use of MOS switches makes it more suitable from integration viewpoint. The functionality of the circuit is verified with SPICE simulations using 0.35？ m
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