Study of the Interference Affecting the Performance of the Theremin

Hindawi Publishing Co po a ion In e na ional Jou nal o An ennas and P opaga ion Volume 2012, A icle ID 348151, 9pages doi:10.1155/2012/348151 Resea ch A icle S udy o he In e e ence A ec ing he Pe o mance o he The emin Ca men Bachille Ma ´ ın, Jo ge Sas e Ma ´ ınez, Amelia Ricchiu i, H´ ec o Es eban Gonz´ alez, and Ca los He n´ andez F anco Uni e si a Poli ` ecnica de Val` encia, Camino de Ve a s/n, 46022 Val` encia, Spain Co espondence should be add essed o Ca los He n´ andez F anco, [email p o ec ed].es Recei ed 3 Oc obe 2011; Accep ed 14 Decembe 2011 Academic Edi o : Miguel Fe ando Copy igh © 2012 Ca men Bachille Ma ´ ın e al. This is an open access a icle dis ibu ed unde he C ea i e Commons A ibu ion License, which pe mi s un es ic ed use, dis ibu ion, and ep oduc ion in any medium, p o ided he o iginal wo k is p ope ly ci ed. The he emin is one o he ea lies elec onic musical ins umen s. I is named a e he Russian physics P o esso Le S. Te men who in en ed i in 1919. This musical ins umen belongs o a e y sho lis o de ices which a e played wi hou physical con ac be ween he musician and he ins umen . he emin playe s complain abou he in e e ence ha any objec in a adius o app oxima ely 3 me e s p oduces when playing he he emin, modi ying he in ona ion o he ins umen . This is a p oblem when playing in small scena ios, wi h o he musicians which mo e a ound i . Wi h he aim o educing he deg ee o in e e ence om nea by obs acles, some me allic isola ing ba s con o ming an an enna a ay can be placed a ound he he emin pi ch an enna. The pape shows diffe en simula ions calcula ed wi h he comme cial so wa e Anso HFSS, a ool which allows h ee-dimensional ull wa e elec omagne ic ield simula ion, wi h adio equencies, millime e and mic o wa es, and expe imen al measu es, bo h showing a educ ion in he effec o he in e e ence. 1. In oduc ion The he emin is one o he ea lies elec onic musical ins umen s [1]. I is named a e he Russian physics P o esso Le S. Te men who in en ed i in 1919. This musical ins umen belongs o a e y sho lis o de ices which a e played wi hou physical con ac be ween he musician and he ins umen . Tha is he ascina ion and he special ea u e o his de ice which e en oday has many ans and suppo e s (see he “The emin Wo ld” websi e [2]). I uses wo an ennas, one o he equency o pi ch con ol and one o he olume o dynamic con ol o he musical no e p oduced. The musician can change bo h pa ame e s by mo ing his/he hands a ound he an ennas. In his case, he elec omagne ic ield a ound he an ennas will be changed and be ecognized by he ha dwa e immedia ely. The ope a ion o he he emin is based on he oscilla ion in a esonan ci cui and he supe he e odyne p inciple. The e a e wo oscilla o s in he ci cui y ha gene a e and con ol he equency o he he emin signal; one o hem is a ixed oscilla o while he o he one is a iable. The equency o he a iable oscilla o is con olled by he mo emen o one o he musician’s hands. When he hand is mo ing nea he an enna, he inpu impedance o he an enna changes p o oking a change in he equency o he a iable oscilla o . When he hand is app oaching, he equency is inc eas- ing, and when he hand is mo ing away, he equency is dec easing. Figu e 1 summa izes a p oposal o he emin block diag am. The signal om he a iable oscilla o is mixed wi h he signal om he ixed oscilla o . Then he esul is il e ed. In his way an acous ic signal can be gene a ed whose pi ch a ies wi h he mo emen s o he musician hand. The ci cui y ha con ols he olume o he signal is also composed by wo oscilla o s, one ixed and he o he one a iable. When he musician hand is app oaching o mo ing away om he olume an enna, a simila change on he inpu 2 In e na ional Jou nal o An ennas and P opaga ion Le hand Lowpass il e Pi ch an enna Volume an enna Volume con ol Loudspeake Righ hand Mixe LC C 1 2 L 1− 2; 1 1+ 2; 2 1− 2 Figu e 1: The he emin block diag am. impedance o he an enna occu s, hus p o oking a change on he equency o he a iable oscilla o . I his a iable equency ma ches wi h he equency o he ixed oscilla o , hen he ou pu signal is maximized, hus p oducing maxi- mum olume o he acous ic signal; o he wise he signal is lowe . The mo emen s o bo h hands do no in e e e wi h each o he because bo h an ennas (monopole o con olling he equency and loop an enna o con olling he olume) p oduce elec ic ields wi h o hogonal pola iza ions. 2. The emin D awbacks Since he appea ance o he i s he emins o nowadays diffe en echnologies has been used o implemen he ci cui y o he ins umen . Ne e heless, he ope a ion p inciple has been always he same. This means ha he echniques o playing he he emin and he difficul ies ha a e associa ed wi h i s ope a ion a e he same now as in 1920: he he emin is difficul o play since he e is no space e e ence, i changes in each scena io and any objec mo ing nea he he emin in e e es and makes he musician ou o une. Mo eo e , he emins p esen he p oblem o nonlinea ope a ion, since he dis ance be ween wo consecu i e no es is diffe en in each oc a e. The wo k o sol ing he nonlinea i y o he he emin was unde aken by Le Te men. He de eloped a he emin o Cla a Rockmo e ha had a nea linea beha iou [1]. Robe Moog in 2000 also de eloped he E he wa e P o, wi h beha iou nea he one o he Cla a’s he emin. Mo eo e , nowadays Thie y F enkel is wo king on he imp o e- men o olume esponse (h p:// he emin. enkel.com/) [3]. Un o una ely, he s udy o he effec o he en i onmen and he in e e ence has been less s udied. Bulle and Monopole an enna Human body Oscilloscope Loudspeake d s Me al ba pa allel o an enna E he wa es he emin Figu e 2: Measu emen se up layou . Wilson did some esea ch conce ning in e e ence du ing he de elopmen o a posi ion senso based on he he emin p inciples [4]. 3. The emin and In e e ences The emin playe s complain abou he in e e ence ha any objec in a adius o app oxima ely 3 m p oduces when playing he he emin, modi ying he in ona ion o he ins umen [5]. This is a p oblem when playing in small scena ios, wi h o he musicians which mo e a ound i . Elec omagne ic ield adia ion pa e ns o he he emin an ennas a e omnidi ec ional. The igh an enna is used o con ol he pi ch wi h ho izon al mo emen s o he hand. Any objec mo ing nea he he emin will al e he pi ch, making he music ou o une. The le an enna con ols he dynamics ( olume) o he sound, wi h e ical mo emen s o he le hand, and hus i is mo e difficul o mo ing objec s o p oduce annoying effec s on he music as wi h he igh an enna. This pape p esen s a s udy o unde s and and minimize he effec o he en i onmen in he he emin ope a ion. 4. How an Obs acle In e e es on he The emin Ope a ion 4.1. Measu emen Se up. In o de o measu e how a human p esence in e e es wi h he pi ch o he he emin, he se up depic ed in Figu e 2 was p epa ed. A 2 me e s long e ical me al ba was posi ioned pa allel o and a a dis ance saway om he he emin monopole an enna ha con ols he pi ch. This me al ba akes he ole o he hand o he musician, so In e na ional Jou nal o An ennas and P opaga ion 3 ha he dis ance scon ols he desi ed in ona ion, wi h he ad an age ha he me al ba does no mo e and main ains he same in ona ion cons an along ime. The ou pu o he he emin is connec ed o an oscil- loscope and o a loudspeake . The oscilloscope is used o measu e he ampli ude and equency o he ou pu sound (which can be hea d a he same ime hanks o he loudspeake ). Finally, a pe son acing he an enna o he he emin app oaches and mo es away om i so ha he dis ance om he pe son o he he emin monopole an enna d a ies om 3 m o 60 cm, measu ed om he lowes pa o he he emin an enna o he wais o he human body a he same heigh . The human body weigh ed 60 Kg and was 160 cms all. The deg ee o in e e ence o he human body is hen measu ed in he ollowing way: i s no human body is placed nea he he emin, and he dis ance s om he he emin an enna o he me al ba ha simula es he musician is adjus ed o he i s no e Cno he oc a e nunde s udy ( he suscep ibili y o in e e ence in 6 oc a es has been measu ed). The co ec no e is ixed by measu ing he equency wi h he oscilloscope and a ying he me al ba posi ion un il he desi ed ou pu equency is achie ed. Nex he in e e ing pe son is placed 3.05 m away om he he emin and he ou pu equency is measu ed wi h he oscilloscope a a gi en se o dis ances o ha pe son s a ing om 3.05 m and ending a 60 cm. Figu e 3 p esen s he equency a ia ion in e ms o musical no es in he wel e- one equal empe amen sys em (12-TET) e sus he in e e ing human body dis ance in me e s, o no es C2,C 3,...,C 7. The ho izon al line in hese igu es indica es an ou o uning o a qua e one highe han he o iginal no e, conside ing he 24-TET. In he highe pi ched no es, he musician hand is so nea he he emin an enna ha he in e e ence effec is qui e small and only affec s i he in e e ing human body is eally e y nea he an enna. On he o he hand, he no e equencies a e mo e diffe en in he high-pi ched a ea and his con ibu es also o educe he effec o in e e ence. In he middle-pi ched a ea, he in e e ence p oduces a highe une o a qua e one in he o iginal no e o dis ances so nea as app oxima ely 1.249 m o C4and 1.05 m o C5. Finally, o he lowe -pi ched a ea, hose dis ances inc ease o app oxima ely 1.665 m o C3and 2.359 m o C2, because o he g ea e dis ance o he musician hand o he an enna o p oduce hese no es and he lowe equency diffe ences be ween musical no es in ha a ea. All hose dis ance alues ha e been ob ained applying linea in e pola ion be ween he measu ed alues, and clea ly hey suppo he complain s o he emin playe s abou he in e e ences ha nea by objec s p oduce in he he emin une. 5. A P oposal o Imp o emen 5.1. Theo e ical Analysis. Wi h he aim o educing he deg ee o in e e ence om nea by obs acles, some me allic isola ing ba s con o ming an an enna a ay can be placed a ound he he emin pi ch an enna. In his sec ion, we show diffe en simula ions calcula ed wi h he comme cial so wa e Anso HFSS, a ool which allows h ee-dimensional ull wa e elec omagne ic ield simula ion, wi h adio equencies, millime e , and mic owa es. Be o e p oceeding wi h he simula ion o he an enna a ay, i was necessa y o model in HFSS he he emin an enna which con ols he pi ch, ha is, he monopole, which is a cylinde wi h a heigh o 462.6 mm and a adius o 4.7 mm. The model o his an enna in HFSS was in ended o be as close as possible o a eal he emin monopole, bu we ound some difficul ies. In he i s place, he he emin wo ks a a equency o 260 kHz, whils he ypical wo king equency o HFSS is o he o de o GHz. This does no mean ha i is no possible o simula e a low equency, bu he e a e some limi a ions ha mus be aken in o accoun . A 260 kHz, he wa eleng h is app oxima ely 1,15 km. A ha equency i we y o connec he monopole wi h a cable smalle han 0.9 mm, he so wa e gi es an e o because he elec ical dimensions a e oo small, and he simula ion can he e o e no be inished. Mo eo e , he an enna needs o be placed in o a adia ion box, wi h abso ben bounda y condi ions. Inside his box, he nea ield is calcula ed and hen om ha he a ield. The dimensions o he box also need o be calcula ed ca e ully, no only because o low equency p oblems, bu also because he bigge he box, he longe i akes he so wa e o calcula e he ield. The ypical way o eed an an enna in HFSS is o c ea e a ec angula wa e po and o connec he eeding cables ha come om he an enna. In he case o a monopole an enna, a cable mus be connec ed o he wa e po and he monopole, and he wa e po mus also be connec ed o he elec ical ea h. Howe e , he size o he eeding cable om he wa e po o he monopole mus ha e ela i ely small dimensions compa ed o he dimensions o he monopole, in o de o gua an ee ha he cable does no i adia e, o a leas ha i s own adia ion is small enough compa ed o ha o he an enna. Howe e , as men ioned p e iously, he dimension o he cable canno be oo small because o he wise i will no ope a e a he equency o 260 kHz. Placing he cable inside a shielding cylinde (e.g., coppe ) ha a oids adia ion is no possible because he shielding cylinde canno be connec ed o he wa e po o o he monopole, and adia ion would leak h ough he unconnec ed ex emes o he cylinde . To o e come his p oblem, we a oided he eeding cable by pu ing he wa e po unde he monopole and connec ing i di ec ly o he monopole. In o de o a oid he in luence o he cable ha connec s he wa e po o he elec ical ea h bo h he ea h and he cable ha connec s o i we e placed ou side he adia ion box. Figu e 4 shows he model c ea ed in HFSS o simula e he monopole an enna and i s a ield adia ion pa e n. As can be seen, he adia ion pa e n is omnidi ec ional, which is he o igin o he in e e ence p oblems o he he emin. 4 In e na ional Jou nal o An ennas and P opaga ion 0.65 0.95 1.25 1.55 1.85 2.15 2.45 2.75 3.05 C2 D2 E2 F#2 G#2 A#2 C3 C#3 D3 D#3 E3 F3 F#3 G3 Musical no es ( equency) Human body dis ance (m) Tune in e e ence C2qua e one up C2: 65.406 Hz (a) 0.65 0.95 1.25 1.55 1.85 2.15 2.45 2.75 3.05 Human body dis ance (m) C3 D3 D#3 E3 F3 F#3 G3 G#3 A3 A#3 Musical no es ( equency) C#3 C3: 130.813 Hz Tune in e e ence C3qua e one up (b) C4 C#4 D4 D#4 E4 Musical no es ( equency) 0.65 0.95 1.25 1.55 1.85 2.15 2.45 2.75 3.05 Human body dis ance (m) Tune in e e ence C4qua e one up C4: 261.626 Hz (c) C5 C#5 D5 0.65 0.95 1.25 1.55 1.85 2.15 2.45 2.75 3.05 Human body dis ance (m) Tune in e e ence C5qua e one up C5: 523.251 Hz Musical no es ( equency) (d) C6 Musical no es ( equency) 0.65 0.95 1.25 1.55 1.85 2.15 2.45 2.75 3.05 Human body dis ance (m) Tune in e e ence C6qua e one up C6: 1046.502 Hz (e) C7 0.65 0.95 1.25 1.55 1.85 2.15 2.45 2.75 3.05 Human body dis ance (m) Tune in e e ence C7qua e one up Musical no es ( equency) C7: 2093.005 Hz ( ) Figu e 3: Resul s o human body in e e ence in he he emin une. In e na ional Jou nal o An ennas and P opaga ion 5 Z X (a) Z X Y The a Phi abs (gain o al) 3.1709e−006 2.9727e−006 2.7745e−006 2.5763e−006 2.3781e−006 2.18e−006 1.9818e−006 1.7836e−006 1.5854e−006 1.3872e−006 1.1891e−006 9.9089e−007 7.9271e−007 5.9453e−007 3.9636e−007 1.9818e−007 0e+000 (b) Figu e 4: (a) Model o he monopole an enna in HFSS, (b) Fa ield adia ion pa e n o he monopole an enna. The inpu impedance o he an enna was also simula ed a diffe en equencies. A 260 KHz, he inpu eac ance (imagina y pa o he impedance) is −j58353 Ω, e y close o he es ima ed alue ob ained using eal pa ame e s o he he emin monopole and he heo e ical o mulas o he inpu impedance o a monopole, which gi es −j61213 Ω[6]. This ag eemen p o es he alidi y o he model used o simula e he an enna. 5.2. Isola ion wi h Pa asi ic Me allic Ba s. TheHFSSmodel is going o be used o simula e he effec o an a ay o pa asi ic me allic ba s which a e placed in o de o isola e he monopole an enna and o educe he in e e ence om a nea by pe son. The in e e ing pe son is modeled in HFSS by a cylinde o sea wa e (humans a e composed o a ound 75% wa e ) wi h a heigh o 900 mm (dis ance om head o wais since he es o he body is ou o he adia ion box) and a adius o 200 mm. When he in e e ing body is placed a a dis ance o app oxima ely 1.7 m, he inpu eac ance is g ea ly changed. I s alue a 260 kHz is −j1413230 Ω. This change in he eac ance while he ins umen is being played supposes g ea changes in he in ona ion o he ou pu sound o he he emin. Now we add he an enna a ay a ound he monopole, see Figu e 5, o assess wha happens o he imagina y pa o he impedance en y. The design o he se o monopoles placed in a semici cle a ound he monopole o he emin was chosen o assu e ha hei p esence would no make signi ican change o he impedance en y o he ins umen . The a ay o an ennas is o med by 6 monopoles wi h a heigh o 450 mm and a squa e c oss sec ion o 20 mm o side leng h. The a ay monopoles a e placed 500 mm away om he he emin monopole and he e is an angle o 40◦be ween each pai o a ay monopoles. Following he simula ion, we achie ed he esul s shown in Figu e 5.I canbeobse ed ha he p esence o he a ay o an ennas push he adia ion ield owa ds he di ec ion whe e he hand o he musician would be. As ega ds o he impedance, he imagina y pa is −77428 Ω. Tha would change he esonance equency and he pi ch o he ou pu sound wi h ega d o he case when no shielding an enna a ay is placed. Ne e heless, he he emin has a od ha allows, in cases o a ia ions o small signi icance, o compensa e impedance shi s and adjus he esonan equency and he pi ch o hei o iginal alues. The size and posi ion o he a ay elemen s ha e been chosen o ensu e ha , when simula ing he model made up o monopole plus obs acle plus an enna a ay, he imagina y pa o he impedance does no change wi h ega d o he case when he obs acle is no p esen , ha is, −77428 Ω. Ne e heless, he simula ions do no model pe ec ly he beha io o he eal an enna, so we made a eal p o o ype o he an enna a ay and es ed i s u ili y and effec i eness. 5.3. Expe imen s. Figu e 6 illus a es he se up used o measu e he isola ion p o ided by he an enna a ay. To his pu pose, we ha e connec ed he ins umen o an oscilloscope and eco ded he equency a ia ions when an obs acle is placed nea he sys em. The a ay is o med by monopoles o aluminium 45 cm all and a squa e c oss-sec ion o 20 mm o side leng h. The a ay monopoles, he he emin, and i s monopole a e all placed a he same le el laying on a wooden suppo (see Figu e 7(a)).Themeasu emen swe edoneinana eabig enough no o ha e o he objec s which could in e e e. F om he beginning eadings, we e aken om he he emin (899 Hz wi h he a ay p esen and 834 Hz wi h- ou ), wi hou any obs acles a ound (excep a me al ba in he icini y o he monopole simula ing he hand o a musician). Then, he equency o he ins umen was measu ed wi h a nea by obs acle, in his case a pe son, a diffe en dis ances (wi h and wi hou he a ay). The audio ou le o he he emin was connec ed o he oscilloscope 6 In e na ional Jou nal o An ennas and P opaga ion Z XY (a) X Z Y The a Phi 3.3498e−016 3.1404e−016 2.9311e−016 2.7217e−016 2.5124e−016 2.3030e−016 2.0936e−016 1.8843e−016 1.6749e−016 1.4655e−016 1.2562e−016 1.0468e−016 8.3745e−017 6.2809e−017 4.1873e−017 2.0936e−017 0e+000 abs (gain o al) (b) Figu e 5: (a) Model o monopole + a ay o an enna, (b) a ield adia ion pa e n. Human body Oscilloscope Loudspeake d s Me al ba pa allel o an enna E he wa es he emin Monopole an enna 40◦ Isola ing ba s R Figu e 6: Schema ic iew. (a) (b) Figu e 7: Measu emen se up layou wi h isola ing ba s: (a) 45 cm isola ing ba s, (b) 2 m isola ing ba s. In e na ional Jou nal o An ennas and P opaga ion 7 0 5 10 15 20 25 30 Va ia ion pe cen ages o he equency Wi hou a ay Wi h i s a ay Wi h second a ay Va ia ion (%) −2.5 −2−1.5 −0.5 Dis ance pe son monopole (m) −3−1 Figu e 8: Cu e showing he in luence o a pe son upon he equency o he he emin ( a ia ion pe cen ages) wi hou he a ay (s aigh cu e), wi h he a ay o monopoles o 45 cm (do ed cu e) and wi h he a ay o monopoles o 2 m (b oken cu e). The C5no e is played. h ough which we e seen he a ia ions in equency. The equency a ia ions we e diffe en o ha ex ac ed om he simula ions. This is because in he simula ion, he effec o wha was unde he le el o he monopole ( he legs o he human body) was no conside ed and in nea ield hey also in e e e. A e analyzing he esul s aken om he i s expe i- men , we buil a new a ay, using he o iginal cons uc ion, bu wi h me allic cylind ical monopoles 2 m high wi h a diame e o 6 mm (see Figu e 7(b)). The new monopoles we e inse ed in o he holes whe e he p e ious monopoles had been sc ewed in o he wooden su ace a e he p e ious ones we e emo ed. The acqui ed eadings om he p e ious expe imen s can be seen in Figu e 8. Figu e 8 clea ly shows he inc ease (in pe cen age) o he equency a ia ion o he he emin li le by li le as he obs acle ge s close o he ins umen . The ac ha he do ed cu e ( ela ing o he p esence o he i s se o a ays buil ) is ound unde nea h he s aigh cu e indica es he isola ion effec (e en i pa ial) achie ed wi h he in oduc ion o he a ay. In consequence, because he b oken cu e ( ela ing o he second se buil ) is ound unde nea h he do ed cu e (and he e o e also unde nea h he s aigh cu e), his indica es ha he isola ion ob ained hanks o he second a ay is much g ea e han ha ob ained wi h he i s . Figu e 9 p esen s he equency a ia ion in he same e ms as Figu e 3. As i happens wi hou he isola ing an enna a ay in he highe -pi ched no es, he musician’s hand is so nea he he emin an enna ha he in e e ence effec is qui e small and only affec s i he in e e ing human body is eally e y close o he an enna. In C7, he e is so li le in e e ence ha he small a ia- ions seem o be due only o ole ances in he measu emen p ocedu e. Howe e , in C6wi h he isola ing a ay he ou o uning emains a lowe a qua e one, and ha is no he case wi hou isola ion (see Figu e 3). In he middle-pi ched a ea, he in e e ence p oduces a highe une o a qua e one in he o iginal no e o dis ances as nea as app oxima ely 1.161 m o C4and 0.986 m o C5, lowe han he same dis ances wi hou isola ion, ha is, 1.249 m o C4and 1.05 m o C5. The e o e, he in e e ing human body p oduces lowe ou o uning a he same dis ance wi h he isola ion ba s. Finally, o he lowe -pi ched a ea hose dis ances inc ease o app oxima ely 1.5068 m o C3and 2.054 m o C2,because o he g ea e dis ance o he musician hand o he an enna o p oduce hese no es and he lowe equency diffe ences be ween musical no es in ha a ea. No e ha hose dis ances whe e 1.665 m o C3and 2.359 m o C2. 6. Conclusions To conclude, he assessmen done shows how, a a musical le el, he a ay p o ed o b ing an o e all imp o emen o he in e e ences, since he a ia ions p o oked by an obs acle app oaching he ins umen a e smalle , and i has o be nea e han be o e o p oduce he same ou o uning. Ne e heless, due o he dec easing equency diffe ence be ween musical no es a he lowe oc a es, and he g ea e musician hand dis ance o he he emin an enna, he iso- la ion in oc a es 2 and 3 is no enough o a sa is ac o y pe o mance. Diffe en solu ions a e possible o be e isola ing he elec omagne ic ield a hose equencies such as conside ing la ge a ay monopoles o building a me allic “ oo ” o e he he emin an enna, app oaching mo e o aFa adayjail. Ou u u e wo k is conside ing bo h solu ions, aking in o accoun ha bo h o hem will also imp o e he 8 In e na ional Jou nal o An ennas and P opaga ion C2 D2 E2 F2 F#2 G2 G#2 A2 A#2 B2 C3 C#3 0.65 0.95 1.25 1.55 1.85 2.15 2.45 2.75 3.05 Human body dis ance (m) Tune in e e ence C2qua e one up C2: 65.406 Hz Musical no es ( equency) (a) 0.65 0.95 1.25 1.55 1.85 2.15 2.45 2.75 3.05 Human body dis ance (m) Tune in e e ence C3qua e one up C3 C#3 D3 D#3 E3 F3 F#3 Musical no es ( equency) C3: 130.813 Hz (b) C4 C#4 D4 Tune in e e ence C4qua e one up 0.65 0.95 1.25 1.55 1.85 2.15 2.45 2.75 3.05 Human body dis ance (m) Musical no es ( equency) C4: 261.626 Hz (c) C5 C#5 0.65 0.95 1.25 1.55 1.85 2.15 2.45 2.75 3.05 Human body dis ance (m) Tune in e e ence C5qua e one up Musical no es ( equency) C5: 523.251 Hz (d) 0.65 0.95 1.25 1.55 1.85 2.15 2.45 2.75 3.05 Human body dis ance (m) Tune in e e ence C6qua e one up C6 Musical no es ( equency) C6: 1046.502 Hz (e) 0.65 0.95 1.25 1.55 1.85 2.15 2.45 2.75 3.05 Human body dis ance (m) Tune in e e ence C7qua e one up C7 Musical no es ( equency) C7: 2093.005 Hz ( ) Figu e 9: Resul s o human body in e e ence in he he emin une wi h isola ing an enna a ay 2 m all. In e na ional Jou nal o An ennas and P opaga ion 9 pe o mance a he es o equencies. The nex s ep will be o ge he playe s’ opinion abou he possibili y o a li e pe o mance su ounded by he e ical a ay, in o de o connec he ob ained esul s wi h eal applica ions. Re e ences [1] A. Glinsky, The emin: E he Music and Espionage, Uni e si y o Illinois P ess, 2000. [2] “The emin Wo ld,” 2011, h p://www. he eminwo ld.com/. [3] Thie y F enkel, “The emin ela ed esea ch, design, modi ica- ions and epai ,” 2011, h p:// he emin. enkel.com/. [4] W. Bulle and B. Wilson, “Measu emen and modeling mu ual capaci ance o elec ical wi ing and humans,” IEEE T ansac ions on Ins umen a ion and Measu emen , ol. 55, no. 5, pp. 1519– 1522, 2006. [5] C. Bachille , C. He n´ andez, and J. Sas e, “Collabo a i e Lea n- ing, Resea ch and Science P omo ion in a Mul idisciplina y Scena io: in o ma ion and Communica ions Technology and Music,” in P oceedings o he In e na ional Con e ence on Enginee ing Educa ion (ICEE ’10), Gliwice, Poland, 2010. [6] C. Balanis, An enna Theo y: Analysis and Design, John Wiley & Sons, 1997.