Please cite this article in press as: Sagbas M, et al. Reply to comment on “Electronically tunable floating inductance simulator”. Int J Electron Commun (AEÜ) (2011), doi:10.1016/j.aeue.2011.04.014 ARTICLE IN PRESS G Model AEUE-50771; No. of Pages 3 Int. J. Electron. Commun. (AEÜ) xxx (2011) xxx–xxx Contents lists available at ScienceDirect International Journal of Electronics and Communications (AEÜ) journal homepage: www.elsevier.de/aeue LETTER Reply to comment on “Electronically tunable floating inductance simulator” M. Sagbas a,∗ , U.E. Ayten b , H. Sedef b , M. Köksal c a Department of Electronics Engineering, Maltepe University, Istanbul, Turkey b Electronics and Communication Eng. Dept., Yildiz Technical University, Istanbul, Turkey c Department of Electronics Engineering, Halic University, Istanbul, Turkey article info Article history: Received 28 December 2010 Accepted 29 April 2011 Keywords: Analog signal processing Floating inductor simulator Current feedback amplification Transconductance amplifiers This paper is a reply to the comment on a previous paper [1], wherein the author compares the floating inductance circuits in [2–4]. This letter is the authors’ answer to the comments in [1] where the floating inductance simulations in [2,3] are compared and it is claimed that the circuit in [2] does not provide any additional feature/advantage over the previous one reported in [3]. Further, it is stated that the circuit in [4] has the current cancellation problem as compared to the circuits in [2,3]. Before replying the main claim asserted by the author in [1] about the circuit in [2], we consider the current cancellation prob- lem he indicated in [1] about the circuit in [4]. The author admit that this problem can be alleviated by a good design of DO-CCCII and fur- ther, referring to the advantages of a bipolar CCCII over bipolar OTA [5] he implies a superiority of the circuit in [4]. We start our reply by noting that the circuit proposed in [2] does not use a DO-OTA as stated by the author of [1], instead it uses an ordinary OTA. The floating inductance simulator circuits given in [2,3] are shown in Fig. 1a and b, respectively. As it is stated in [1], the first ends of both the circuits in [2,3] are the same. But the rest of the circuits are different so that a DO- CCCII is used in [2] whilst a DO-OTA is used in [3]. These active components perform the same function which is also stated by the comment in [1]. Further, the comment indicates the advantages of bipolar CCCIIs over bipolar OTAs as explained in [5]. In this respect, ∗ Corresponding author. Tel.: +90 216 626 10 50. E-mail addresses: sagbas@maltepe.edu.tr, sagbasm@gmail.com (M. Sagbas), ayten@yildiz.edu.tr (U.E. Ayten), sedef@yildiz.edu.tr (H. Sedef), muhammetkoksal@halic.edu.tr (M. Köksal). the simulation proposed in [2] should have superiority over the one given in [3]. On the contrary, the comment [1] claims that this advantage is limited using DO-OTA in [2] and hence the simulations proposed in [2] do not provide any additional feature/advantage over the previously reported circuit in [3]. In fact, DO-OTA is not used in the floating inductance simulation of [2] as shown in Fig. 1a, and for this reason the degradation made by the comment [1] about the circuit in [2] is not faithful. Other circuits similar to the circuit structure in [2] are reported in the literature. For example, in the floating immitance simula- tion given in [6] DO-CCII is used instead of DO-CCCII. This way it is shown that not only the floating inductance but a floating capaci- tance and a floating resistance can also be realized by connecting different passive components to the x-terminal. Such a capacity does not exist in the structure of the circuit in [3]. Apart from this, a new active component CBTA (current backward transconductance amplifier) based on this structure has just been introduced to the literature [7,8]. The advantages of the filter circuits are betrayed therein. These filter structures cannot be realized using the circuit structure in [3]. Therefore the floating inductance simulator given in [2] has additional features and advantages over the one in [3]. In fact, it is a general approach that the floating inductance is obtained by taking the voltage difference and converting it to a current which is applied to a capacitor. Then, the voltage on the capacitor is converted to the current and feed backed to the input terminals. Almost all of the floating inductance simulators includ- ing the ones in [2,3] are based on this principle. The differences in the circuits proposed in the literature for inductance simulation appear in the kinds of the active elements used and the way of their interconnections with the passive R and/or C components. Depending on the properties of the active components and the 1434-8411/$ – see front matter © 2011 Elsevier GmbH. All rights reserved. doi:10.1016/j.aeue.2011.04.014