8 IKEUCHI, M., SAWAMI, H., and NIKI, H. : 'Analysis of open-type dielec- tric waveguides by the finite-element iterative method', IEEE Trans., 1981, MTT-29, pp. 234-239 9 YASUURA, K., SHIMOHARA, K., and MIYAMOTO, T. : 'Numerical analy- sis of a thin-film waveguide by mode-matching method', J. Opt. Soc. Am., 1980, 70, pp. 183-191 10 RAMASWAMY, v.: 'Propagation in asymmetrical anisotropic film waveguides', Appl. Opt., 1974,13, pp. 1363-1371 11 STEINBERG, R. A., and GIALLORENZI, T. G.: 'Modal fields of aniso- tropic channel waveguides', J. Opt. Soc. Am., 1977, 67, pp. 523-533 0013-5194182/100411-03$1.50/0 NOVEL LOSSLESS SYNTHETIC FLOATING INDUCTOR EMPLOYING A GROUNDED CAPACITOR Indexing terms: Circuit design, Current conveyors, Inductance simulation, Active networks A new lossless synthetic floating inductance circuit, em- ploying a grounded capacitor and CC Us as active elements, is presented which, in contrast to recently reported circuits, does not require any component-matching condition for the desired realisation. The other novel features of the circuit are use of a minimum possible number of passive components and inductance control through a single grounded resistor. Whereas it is impossible to simulate a floating inductance (FI) with operational amplifier (OA)-RC networks without re- quiring any component-matching conditions, 1 recent works appearing in this journal 2 ' 4 ' 5 and elsewhere 3 have shown that using current conveyors (CC) as active elements it is possible to evolve synthetic floating inductance circuits which have the remarkable feature of not requiring any component-matching condition for the desired realisation. Additional notable fea- tures of these circuits were use of a minimum possible number of passive components 2 ' 3 ' 5 (only two resistors and a capacitor) and independent control of realised inductance through a single resistance. 4 ' 5 More recent works appearing in this journal 6 " 8 have pres- ented FI configurations employing a grounded capacitor (GC) along with four CC Us from the point of view of integrated circuit (IC) implementation. However, these circuits do require matching of passive components for FI simulation, and thus do not have the remarkable feature of the circuits of Reference 2-5. From the IC implementation viewpoint the FI configur- ation would be the most suitable which not only employs a GC but also has all the remarkable features of the earlier circuits of References 2-5. The aim of this letter is to present a new circuit which does possess all these features. CCII 0 Y Xr—1 CCII 0 CCII 0 '*« f [ CCII 0 [2967T1 L. Fig. 1 New circuit which simulates a single-resistance-controlled loss- less floating inductance with minimum unmatched passive components The new circuit is shown in Fig. 1 and employs three CC Us (i y = 0, v x = v y , i. = ± i x ) and one CC I* (i y = i x , v x - v y , i z = ±i x ). The analysis of this circuit gives: v 3 h = I'sl = + »*1 = ~'y2 = ~'x2 = + £~ y2 since v x2 = v y2 = v xl = v yl = i; 3> t'-« (1) (2) and ~' 13 ' SC Vl ~ »2 sc/? 7 sc /?, sc (3) since v x3 = v y3 = v x and v x4 = v y4 . = v 2 , so that the 7-matrix of the circuit is given by SCK,/? 2 |_-1 IJ and the circuit simulates an FI with (4) (5) In this circuit if the position of i? t and C is interchanged, the circuit would simulate a floating capacitor with r - (6) and in this mode the circuit can be used for capacitance floa- tation. Note that a large-valued floating capacitance can be obtained from a low-valued grounded capacitor due to the scale factor (R l /R 2 ). Note that, apart from using a GC, the new circuit: (i) does not require any component-matching to arrive at eqn. 4 (ii) uses a minimum number of passive components (iii) provides independent control of L eq or C eq through a single grounded resistor R v RAJ SENANI 9th March 1982 Electrical Engineering Department MNR Engineering College Allahabad-211004, India References 1 SENANI, R.: 'Some new synthetic floating inductance configur- ations', AEU, 1981, 35, pp. 307-310 2 SENANI, R.: 'Novel active-RC circuit for floating inductor simula- tion', Electron. Lett., 1979, 15, pp. 679-680 3 SINGH, v.: 'A new active RC circuit realisation of floating induct- ance', Proc. IEEE, 1979, 67, pp. 1659-1660 4 SENANI, R.: 'Novel active RC circuit realisations of tunable floating inductors', Electron. Lett., 1980,16, pp. 154-155 5 SENANI, R.: 'New tunable synthetic floating inductors', ibid., 1980, . 16, pp.382-383 6 PAL, K.: 'Novel floating inductance using current conveyors', ibid., 1981,17, p. 638 7 SINGH, v.: 'Active-RC single-resistance-controlled lossless floating inductance simulation using a single grounded capacitor', ibid., 1981,17, pp. 920-921 8 PAL, K.: 'New inductance and capacitor-floatation schemes using current-conveyors', ibid., 1981, 17, pp. 807-808 * In the light of the recent work of References 10 and 11 it may be seen that as far as the circuit complexity and total-component-count involved in the integrable hardware implementation of CCs is con- cerned, a CC I is as easily implementable as a CC II ELECTRONICS LETTERS 13th May 1982 Vol. 18 No. 10 413