Dual-Mode Multifunctional Reconnection-less Reconfigurable Filter

ELEKTRONIKA IR ELEKTROTECHNIKA, ISSN 1392-1215, VOL. 26, NO. 3, 2020 1Abs ac —A no el solu ion o a econnec ion-less econ igu able il e is being p esen ed. The il e wo ks in he cu en mode, ol age mode, and mixed mode ( ol age ocu en ) o e ing six een ans e unc ions in o al. The s uc u e u ilizes a ol age di e encing ansconduc ance ampli ie , cu en ollowe and ol age, and cu en ampli ie s. The designed s uc u e o e s he con ol o he pole equency and quali y ac o and he adjus men o he band-s op/band- pass a ea o a ailable unc ions. The p oposed design is suppo ed by he PSpice simula ions using a ailable simula ion models. Index Te ms—Cu en mode; Elec onic con ol; Elec onic econ igu a ion; F equency il e ; Mixed mode; Vol age mode. I. INTRODUCTION The e sa ili y o equency il e s, as one o he mos undamen al and commonly used unc ional blocks in he indus y, is o en a desi ed p ope y. A common a emp in case o he design o equency il e s is ha he il e p o ides mul iple ans e unc ions o e en be e all s anda d ans e unc ions (all pass (AP), band s op (BS), high pass (HP), band pass (BP), and low pass (LP) ) i possible. These s uc u es a e usually based on he ac ha hey include ei he mul iple inpu nodes, mul iple ou pu nodes o bo h. A ce ain amoun o p oposed solu ions [1]–[10] o e s ans e unc ions in mul iple ope a ional modes in o de o inc ease he e sa ili y o a gi en il e . The pape s s a e ha he il e s in [1]–[5] p o ide unc ions in he cu en mode (CM), as well as in he ol age mode (VM). The il e in [6] o e s unc ions o he cu en and ansimpedance ( ol age o cu en ) mode, while pape [7] p esen s a il e ope a ing in ol age and ansimpedance mode. Some o he s uc u es [1]–[7] can also o e some unc ions o di e en modes, bu his possibili y was no in oduced wi hin he pape . Remaining e e ences [8]–[10] in oduce il e s wo king wi h all possible combina ions - cu en , ol age, ansimpedance, and ans esis ance (cu en o ol age) mode. Se e al solu ions [4], [5], [10], a some poin , include loa ing capaci o s in o de o p o ide ce ain unc ions. I is a well-known ac ha loa ing capaci o s a e unsui able o Manusc ip ecei ed 11 Feb ua y, 2020; accep ed 16 May, 2020. Fo he esea ch, in as uc u e o he SIX Cen e was used. he in eg a ion. As men ioned ea lie , hese s uc u es ha e ei he mul iple inpu nodes, mul iple ou pu nodes o bo h. This as well is a disad an ageous p ope y since i is necessa y o swi ch be ween he inpu and ou pu nodes o gi en s uc u e o he pu pose o changing he desi ed unc ion. In such case, a swi ching logic needs o be designed and added on he chip. Also, i he swi ching be ween unc ions is con olled s ic ly digi ally, we a e limi ed in he ma e o ine uning o ou pu esponses. Mo eo e , he solu ion in [4] equi es a s uc u e modi ica ion o be able o ope a e in a di e en mode. Reconnec ion-less econ igu able il e s [11]–[17] b ing a possible solu ion o he abo e-men ioned p oblem as he esul ing ou pu esponse is se h ough he elec onically con ollable elemen s, which a e usually con olled by DC cu en o DC ol age, which can be ex e nally applied o he chip. To he bes o au ho ’s knowledge, he e has been no epo o a econnec ion-less econ igu able il e o e ing i s unc ions in mul iple ope a ional modes. Table I p o ides a b ie compa ison o he design in oduced in his pape wi h ele an p e iously p oposed solu ions. II. DESIGN DESCRIPTION The il e ’s co e is based a ound a ol age di e encing ansconduc ance ampli ie (VDTA) [18]. A cu en ollowe (CF) [19], a iable gain ampli ie s (VGAs) [20], and adjus able cu en ampli ie s (ACAs) [21] a e hen sui ably added o he ci cui . The CF has been added so he HP esponse can be aken om he high-impedance node ins ead o being aken h ough C1 (in case o he CM) when he capaci o could no be g ounded. The CF p o ides a copy o a cu en om he inpu node a ailable om a high- impedance ou pu a he han h ough he capaci o . VGAs and ACAs hen p o ide he econnec ion-less econ igu a ion o he esul ing ans e . The VDTA can be desc ibe by he ma ix (1). The in e -s uc u e o he VDTA is c ea ed by wo ope a ional ansconduc ance ampli ie s (OTAs) [20] as shown in Fig. 1, oge he wi h he schema ic symbol o he VDTA. The OTAs ha e been implemen ed by uni e sal cu en con eyo s (UCCs) [22] ( e minal Y1 and Y2 a e used as di e en ial ol age inpu s, e minal X is g ounded h ough a esis o R = 1/gm) in his pa icula case. Dual-Mode Mul i unc ional Reconnec ion-Less Recon igu able Fil e Lukas Langhamme 1, *, Roman So ne 1, Jan D o ak1, Tomas Dos al2 1Facul y o Elec ical Enginee ing and Communica ion, B no Uni e si y o Technology, Technicka 12, 61600 B no, Czech Republic 2Depa men o Technical S udies, College o Poly echnics, Tols eho 16, 58601 Jihla a, Czech Republic [email p o ec ed] h ps://doi.o g/10.5755/j01.eie.26.3.25856 36 ELEKTRONIKA IR ELEKTROTECHNIKA, ISSN 1392-1215, VOL. 26, NO. 3, 2020 TABLE I. RECENTLY INTRODUCED RECONNECTION-LESS RECONFIGURABLE FILTERS COMPARED TO THE PROPOSED DESIGN. Re . No. [11] [12] [13] [14] [15] [16] [17] Fig. 4 Yea 2015 2019 2015 2019 2016 2018 2019 - No. o ac i e/passi e elemen s 4/2(3)1 5/4 4/2 5/2 2/3 4/4 4/2 8/2 All capaci o s g ounded No Yes No Yes2 Yes Yes No Yes3 Ope a ional mode VM CM VM CM CM VM VM CM, VM, (V→I) No. o a ailable unc ions 7 6 7 9 5 7 6 7+7+2 No e: 1 – con ains mul iple solu ions, 2 – one o he capaci o s is i ually g ounded h ough he cu en inpu , 3 – one o he capaci o s is i ually g ounded h ough ol age ou pu s o VGA elemen s. 11 11 2 2 0 0 0 0 0 0 0 0 00 . 00 0 0 0 0 0 0 p np mm Zn mm ZZ m XZ m X I IV gg IV gg IV g IV g I                                  (1) VDTA VDTA + _gm1 + _gm2 In Ip Vn Vp IX- IX+ VX- VX+ X+ X- X+ X- Z+ Z- p n IZ+ IZ- VZ- VZ+ Ip Vn Vp IX+ VX- VX+ IZ+ IZ- VZ- VZ+ InIX- Z+ Z- p n OTA1OTA2 a) b) Fig. 1. Vol age di e encing ansconduc ance ampli ie (VDTA): a) Schema ic symbol; b) Implan a ion o i s in e nal opology by wo OTAs. The CF is desc ibed by ela ion Iou ± = ±Iin and i s schema ic symbol, and implemen a ion by he UCC can be seen in Fig. 2. The VGAs we e implemen ed by comme cially a ailable de ices VCA822 [23] wi h hei ol age gain A con olled by he DC con ol ol age VSET_A. Thei unc ion can be exp essed as Vou ± = ±AVin. The las used elemen ACA is c ea ed by comme cially a ailable de ices EL2082 [24]. The beha io o he ACA ollows a ela ion Iou ± = ±BIin, whe e he cu en gain B is con olled by he DC con ol ol age VSET_B. The schema ic symbols o he VGA and ACA a e depic ed in Fig. 3. CF IOUT+ IOUT- Y1 Y2 Y3 X Z1+ Z1- Z2+ Z2- UCC b) IOUT+ IOUT- IIN IIN a) Fig. 2. Cu en ollowe : a) Schema ic symbol; b) I s implemen a ion by he UCC. B ACA VSET_B IOUT IIN a) b) + _ VSET_A VGA AVOUT VIN- VIN+ Fig. 3. Schema ic symbols: a) Adjus able cu en ampli ie (ACA); b) Va iable gain ampli ie (VGA). The p oposed il e is p esen ed in Fig 4. The s uc u e was designed in such way ha he inpu ol age is dis ibu ed in o di e en nodes o he il e since he ol age can be easily aken om one node and i does no equi e an addi ional ac i e elemen o dis ibu e he inpu ol age in compa ison o he ol age summa ion. In case o he CM, on he o he hand, he cu en s o indi idual esponses a e summed up in one node as he cu en summa ion can be made wi hou a necessi y o an ex a ac i e elemen in compa ison o he cu en dis ibu ion. The i s OTA in he VDTA s uc u e has been implemen ed by mul iple ou pu elemen , so i can o e one addi ional Z ou pu (Z - in his case). The nega i e inpu o he second OTA is no g ounded, bu used as an inpu (labeled as in Fig. 4). The capaci o C1 and nega i e inpu s o he i s and second OTAs in he VDTA s uc u e a e i ually g ounded h ough he ou pu s o VGA elemen s aking in o conside a ion he ac ha he ol age ou pu has ze o impedance in he ideal case. CF B1 ACA1VSET_B1 IIN + _ VSET_A1 VGA1 A1 C1 VOUT IOUT B2 VSET_B2 B3 VSET_B3 ACA2 ACA3 + _ VSET_A2 VGA2 A2+ _ VSET_A3 VGA3 A3 VIN VDTA X+ X- Z+ Z- p n Z- C2 Fig. 4. P oposed dual-mode mul i unc ional econnec ion-less econ igu able il e . The denomina o common o bo h he CM and VM is gi en as 211221 2 )( mmm gggCCCD  sss . (2) 37 ELEKTRONIKA IR ELEKTROTECHNIKA, ISSN 1392-1215, VOL. 26, NO. 3, 2020 The nume a o in case o he VM is 21 2 1 2 2 3 2 1 2 1 2 2 ( ) ( ) , mm mm N CC A C g A C g A g g A       s s s (3) and he nume a o o he CM is 21 2 3 2 1 2 1 2 1 () m m m N CC B C g B g g Bs s s . (4) As i can be seen, he esul ing ou pu esponse depends on he se ing o ol age gains A o he VM and cu en gains B o he CM all con olled elec onically by DC ol ages. The il e p o ides all s anda d ans e unc ions (AP, BS, HP, BP, and LP) in bo h modes. The se ing o con ol ol ages in dependence on he esul ing ou pu esponse is s a ed in Table II. The il e also o e s unc ions BP and HP (bo h pola i ies) o he mixed mode ( ol age o cu en ). The con ol ol ages can be unde s ood as ollows: A = 0 o -1 V, A = 1 o 0 V, and A = 2 o 1 V when e e ing o he VGA and B = 0 o 0 V and B = 1 o 1 V in case o he ACA. The pole equency and quali y ac o o he il e in bo h cases a e exp essed as: 12 0 12 1, 2 mm gg CC   (5) 12 21 . m m Cg QCg  (6) The e o e, 0 can be con olled wi hou a ec ing Q by he change o gm1 and gm2 i a simple condi ion gm1 = gm2 is ul illed. Simila ly, Q can be con olled wi hou a ec ing 0 by changing he a io be ween gm1 and gm2 as long as he esul o he mul iplica ion o gm1 and gm2 emains unchanged. TABLE II. THE SETTING OF THE CONTROL VOLTAGES IN RELATION TO PARTICULAR OUTPUT RESPONSE. VM HP BP LP BS AP VSET_A1 0 V -1 V -1 V 0 V 0 V VSET_A2 -1 V -1 V 0 V 0 V 0 V VSET_A3 -1 V 0 V 0 V 0 V 1 V CM HP BP LP BS AP VSET_B1 0 V 0 V 1 V 1 V 1 V VSET_B2 0 V 1 V 0 V 0 V 1 V VSET_B3 1 V 0 V 0 V 1 V 1 V III. VERIFICATION The e i ica ion o he design has been made wi h he help o PSpice simula ions in ol ing a ailable simula ion models o he UCC and comme cially a ailable de ices VCA822 and EL2082 o implemen ac i e elemen s in he way sugges ed in he p e ious sec ion. The alues o ansconduc ances and he passi e pa s we e chosen o be gm1 = gm2 = 1 mS and C1 = C2 = 1 nF. The e o e, he heo e ical alues o he pole equency and quali y ac o a e equal o 0 = 159.2 kHz and Q = 1. The cu en mode ans e unc ions o BS, HP, BP, and LP ob ained om he simula ions a e compa ed wi h he heo e ical expec a ions in Fig. 5. Simila ly, he same ans e unc ions, bu his ime o he ol age mode, a e p esen ed in Fig. 6 again compa ed wi h he heo e ical expec a ions. In bo h cases, we can see a good alignmen o he simula ion esul s wi h he heo y. E en ual di e ences a lowe and highe equencies a e due o pa asi ic cha ac e is ics o used ac i e elemen s and hei bandwid h limi a ions. Low pass High pass Theo y Band pass Band s op Fig. 5. T ans e unc ions o BS, HP, BP, and LP in case o he CM: simula ion esul s (colo ed solid cha ac e is ics) and heo y (black dashed cha ac e is ics). Low pass High pass Theo y Band pass Band s op Fig. 6. T ans e unc ions o BS, HP, BP and LP in case o he VM: simula ion esul s (colo ed solid cha ac e is ics) and heo y (black dashed cha ac e is ics). The band-s op unc ion o he ol age mode has been selec ed o he p esen a ion o he con ollabili y o 0. This abili y is demons a ed o i e di e en se ings o alues o ansconduc ances gm1, gm2 (gm1 = gm2). The chosen alues a e 560 µS, 750 µS, 1 mS, 1.33 mS, and 1.77 mS esul ing in he heo e ical 0 o 89.1 kHz, 119.4 kHz, 159,2 kHz, 211.7 kHz, and 281.7 kHz. The ob ained simula ion esul s a e depic ed in Fig. 7. Theo y gm1 = gm2 = 568 µS 0 = 87.9 kHz gm1 = gm2 = 750 µS 0 = 115.9 kHz gm1 = gm2 = 1 mS 0 = 155.6 kHz gm1 = gm2 = 1.33 mS 0 = 205.1 kHz gm1 = gm2 = 1.77 mS 0 = 272.9 kHz Fig. 7. The con ollabili y o 0 demons a ed o i e di e en se ings o ansconduc ances gm1 and gm2. The alues o 0 acqui ed om he simula ion a e compa ed wi h he heo e ical alues in Table III. The 38 ELEKTRONIKA IR ELEKTROTECHNIKA, ISSN 1392-1215, VOL. 26, NO. 3, 2020 ob ained simula ion esul s show sligh ly lowe alues han he heo e ical p esump ions, ne e heless he esul s yield only small di e ence, which can be easily compensa ed assuming he elec onic con ol o he ansconduc ances. I would be possible o p o ide an elec onic con ol o 0 and Q by a di e en ype o implemen a ion o he OTA elemen un o una ely, he comme cially a ailable elemen s wi h he elec onic con ol o hei ansconduc ance usually o e only one ou pu and i would ha e o be cons uc ed by mul iple ac i e elemen s. TABLE III. THE CONTROL OF THE POLE FREQUENCY. gm1, gm2 560 µS 750 µS 1 mS 1.33 mS 1.77 mS 0 heo e ical [kHz] 89.1 119.4 159.2 211.7 281.7 0 simula ed [kHz] 87.9 115.9 155.6 205.1 272.9 The s op-band a ea (as much as he pass-band a ea) o a ailable unc ions can be easily adjus ed i equi ed. This can be seen in Fig. 8 demons a ed on he CM band-pass unc ion. The band-s op a ea a lowe equencies can be con olled by he adjus men o he alue o cu en gain B1, while he band-s op a ea a highe equencies can be adjus ed by B3. In simila manne , he band-s op/band-pass a eas o he VM unc ions can be adjus ed by changing he alue o A2 o lowe equency band and A1 o highe equency band. This ea u e also allows he il e o o e special unc ions o high-pass and low-pass wi h ans e ze o (HPZ, LPZ). The se ing o he Fig. 8 is as ollows VSET_B1 (o VSET_B3) = 0.1 V, 0.03 V, and 0.01 V. The colo ed solid lines show he adjus men o he highe equency band (con olled by B3) and he black dashed lines s and o he adjus men o he lowe equency band (con olled by B1). VSET_B3 = 0.03 V VSET_B3 = 0.01 V VSET_B3 = 0.1 V VSET_B1 = 0.1 V VSET_B1 = 0.03 V VSET_B1 = 0.01 V Fig. 8. Demons a ion o he adjus abili y o he band-s op a eas o he CM band-pass unc ion o a ious se ings. The u he analysis o he p oposed il e ing s uc u e includes a sensi i i y analysis. The ab ica ion misma ch (ce ain inaccu acy o indi idual ou pu s o each ac i e elemen and he ole ance o used passi e pa s) can signi ican ly in luence he esul ing ans e cha ac e is ics. Based on his ac , he il e ope a ing in he CM in ol es 12 pa ame e s (C1, C2, gm11, gm12, gm13, gm21, gm22, n1, n2, B1, B2, and B3) and 9 pa ame e s (C1, C2, gm11, gm12, gm21, n1, A1, A2, and A3) in he VM. Pa ame e s gm11, gm12, gm13, gm21, and gm22 a e ansconduc ances o indi idual ou pu s o OTA elemen s wi hin he VDTA, n1 and n2 a e ans e s o indi idual ou pu s o he CF, pa ame e s B1, B2, and B3 a e cu en gains o indi idual ACA elemen s, and, inally, A1, A2, and A3 s and o he ol age gains o VGAs. The co esponding denomina o (common o bo h cu en and ol age modes) conside ing hese pa ame e s akes a o m o 21 2 2 11 1 12 21 1 ( ) . eal m m m D CC C g n g g n  s s s (7) The eal nume a o s o he il e wo king in he CM and VM a e gi en by he ollowing equa ions: 2 _ 1 2 2 3 2 13 1 2 12 22 1 1 () , eal CM m mm N C C n B C g n B g g n B     s s s (8) 2 _ 1 2 1 2 11 1 2 2 21 1 3 12 21 1 2 ( ) ( ). eal VM m m m m N C C A C g n A C g n A g g n A     s s s . (9) The ela i e sensi i i y o he il e o a change o an indi idual pa ame e can be desc ibed as [25]   ( ) ( ) __ Re , K j K j R qi R qi SS   (10) whe e K = K(jω) is a complex ans e o he il e K = IOUT/IIN and qi ep esen s i h pa ame e o he il e . Maple ool was used o pe o m he ma hema ical exp ession o he sensi i i ies. Figu es 9 and 10 show he esul s o he sensi i i y analysis ac oss whole equency ange om 100 Hz o 100 MHz. Fig. 9. Rela i e sensi i i y o he HP unc ion o he CM o indi idual pa ame e s in dependence on he equency. Figu e 9 shows he esul s o he HP unc ion in case when he p oposed il e ope a es in he cu en mode (sensi i i ies o pa ame e s gm12, gm22, B1, and B2 a e ze o as hese pa ame e s a e no con ained in he ans e unc ion o he HP unc ion) and Fig. 10 p esen s he esul s o he LP unc ion in case o he VM (sensi i i y o A1 is ze o). F om he g aphs, i can be seen ha all sensi i i ies a e ela i ely low ( hey a e a ound one, which is he ypical alue). The highes sensi i i y is a ound he pole equency o he il e (159.2 kHz), which is well known ac . The DC ans e unc ion o LP in case o bo h modes we e ca ied ou (Figs. 11 and 12) in o de o show he a ailable egion, whe e he ci cui ac s linea ly. 39 ELEKTRONIKA IR ELEKTROTECHNIKA, ISSN 1392-1215, VOL. 26, NO. 3, 2020 Fig. 10. Rela i e sensi i i y o he LP unc ion o he VM o indi idual pa ame e s in dependence on he equency. Fig. 11. Dynamic ange o he LP unc ion o he CM. Fig. 12. Dynamic ange o he LP unc ion o he VM. IV. CONCLUSIONS The p oposed il e can p o ide 16 unc ions in o al in h ee ope a ion modes (7 in he CM, 7 in he VM, and 2 in case o ol age o cu en ans e ) in co espondence wi h he se ing o elec onically con ollable pa ame e wi hou any equi ed s uc u e modi ica ion. The in ended unc ion has been e i ied by PSpice simula ion and shows good ag eemen wi h he heo y. The il e also o e s a simple con ol o i s pole equency (see Fig. 7) and adjus men o he band-s op/band-pass a eas o a ailable unc ions (see Fig. 8). CONFLICTS OF INTEREST The au ho s decla e ha hey ha e no con lic s o in e es . REFERENCES [1] C. Lee, “Independen ly unable mixed-mode uni e sal biquad il e wi h e sa ile inpu /ou pu unc ions”, In e na ional Jou nal o Elec onics and Communica ions (AEÜ), ol. 70, pp. 1006–1019, 2016. DOI: 10.1016/j.aeue.2016.04.006. [2] M. Gup a, T. S. A o a, and S. N. Gup a, “A no el cu en -mode and ol age-mode all pass il e employing ope a ional ansconduc ance ampli ie ”, in P oc. o 2016 IEEE 1s In e na ional Con e ence on Powe Elec onics, In elligen Con ol and Ene gy Sys ems (ICPEICES), Delhi, India, 2016, pp. 1–3. DOI: 10.1109/ICPEICES.2016.7853058. [3] T. E aghzou i, N. Hassen, and K. 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