HEMT Transistor Noise Modeling using Generalized Radial Basis Function

Transcription

1 ICSE 8 Proc. 8, Johor Bahru, Malaya HEMT Trator Noe Modelg ug Geeralzed adal Ba ucto Mohe Hayat, Al Shamha, Abba ezae, Majd Sef Electrcal Egeerg Deartmet aculty of Egeerg, az Uverty Tagh-E-Bota, Kermahah-6749, Ira (Phoe), (ax), mohe_hayat@yahoo.com, al.hamha@yahoo.com, arezae88@yahoo.com, majdfy@gmal.com Abtract: I th aer, oe mortat archtecture of eural etwor amed a geeralzed radal ba fucto (GB) aled order to model HEMT Trator Noe Parameter deedece o ba codto uch a dc dra-to-ource voltage, dc dra-to-ource curret, frequecy ad S- arameter that ca accurately redct trator oe arameter a wde frequecy rage for all ba ot from the oeratg rage cludg trator S- arameter. Keyword: Geeralzed adal Ba ucto, HEMT Trator, S-Parameter. I. INTODUCTION Accurate ad relable oe model of mcrowave trator are eceary for aalye ad deg of mcrowave actve crcut that are art of moder commucato ytem, where t very mortat to ee the oe at a low level. Model develomet bacally a mzato roce ad ca be tme-coumg. urthermore, meaured gal ad oe data for each ew oeratg ot are eceary for model develomet, whch could tae much effort ad tme, ce thee meauremet requre comlex equmet ad rocedure [, ]. I may of thee cae, eural modelg could be a good alteratve to the clacal modelg. Neural model are mler ad reta the mlar accuracy. They requre le tme for rovdg reoe, therefore, alcato of eural model ca mae mulato ad mzato rocee le tme-coumg, hftg much comutato from o-le mzato to off-le trag. Neural etwor have bee aled modelg of ether actve devce or ave comoet, mcrowave crcut aaly ad deg, etc. It ha bee rooed mcrowave MESET ad HEMT trator gal ad oe erformace modelg [3-5]. I th aer, a Geeralzed adal Ba ucto (GB) etwor for HEMT trator oe modelg rooed. Th etwor receve ba uch a dc dra-to-ource voltage, dc dra-to-ource curret, frequecy ad S- arameter a ut ad roduce trator oe arameter at t outut. Therefore, ba codto ad frequecy are ut ad mmum oe fgure, magtude of mum reflecto coeffcet, agle of mum reflecto coeffcet ad ormalzed equvalet oe retace are outut of the eural etwor. A mlfed overvew of rooed ANN model how g.. v d f d GB Model g. A mlfed overvew of ANN model. m Γ Γ The GB etwor a geeralzato of the B etwor, whch allow to dfferet varace for each dmeo of the ut ace by relacg the radal Gaua erel wth elltcal ba fucto. The 475

2 ICSE 8 Proc. 8, Johor Bahru, Malaya umber of ode the hdde layer of the geeralzed B etwor M, where M ordarly maller tha the umber of euro the hdde layer of B etwor. I GB etwor, the lear weght aocated wth the outut layer, ad the oto of the ceter of the radal ba fucto ad the orm weghtg matrx aocated wth the hdde layer, are all uow arameter that have to be leared[6]. II. TANSISTO NOISE PAAMETES A two-ort oy comoet ca be characterzed by a oe fgure [, 7], exreed a 4 Γg Γ = m + z o Γ g +Γ where m a mmum oe fgure, a equvalet oe retace, Γ the mum reflecto coeffcet, ad fally, z o ormalzg medace. The mum reflecto coeffcet refer to the mum ource medace that reult mmum oe fgure, = m. The oe arameter m, Γ ad decrbe heret behavor of the comoet ad are deedet of a coected crcut. III. GB NETWOK Multlayer ercetro (MLP) eural etwor have bee aled modelg of mcrowave trator oe, deedece o frequecy ad ba codto [8, 9]. I th aer, frt we decrbe radal ba fucto (B) ad the cocetrate o the alcato of GB etwor. A radal ba fucto etwor a eural etwor aroached by vewg the deg a a curve-fttg (aroxmato) roblem a hgh dmeoal ace. Learg equvalet to fdg a multdmeoal fucto that rovde a bet ft to the trag data, wth the crtero for bet ft beg meaured ome tattcal ee. There are dfferet learg tratege the deg of a B etwor deedg o how the ceter of B of the etwor are determed. There are three major aroache to determe the ceter [6]: - xed Ceter Selected at adom: I th aroach, the locato of the ceter may be choe radomly from the trag data. - Self orgazed Selecto of Ceter: I the ecod aroach, the radal ba fucto ca move the locato of ther ceter a elforgazed faho. - Suerved Selecto of Ceter: I the thrd aroach, a uerved learg roce emloyed to obta the ceter of the radal ba fucto ad all other free arameter of the etwor. I other word, the B etwor tae o t mot geeralzed form. A atural caddate for uch a roce error correcto learg, whch mot coveetly mlemeted ug a gradet-decet rocedure that rereet a geeralzato of the LMS algorthm. Secfcally, we coder a exteo of the B etwor whch allow a dfferet varace for each ut dmeo. The relaxato of the radal cotrat traform the tadard Gaua erel wth crcular ymmetry to elltc ba erel, whch ca reduce the dmeoalty of the ut ace. Th cheme deoted a GB etwor. The learg algorthm chooe the GB ceter oe by oe order to mmze the outut error. After electg each ew ceter from the trag et, the ceter ad varace of the global etwor are mzed by alyg gradet decet techque. The error fucto gve by E = ( y ) g ad the gradet equato for the varace ad ceter are E σ j E μj v ( ) ( ). j μj = e v o v λ σ j σ j = e v o v ( ) ( ) λ. σ j )) σ j v j μj where dexe the ut atter, the outut dmeo, v the th ut atter, y ) the dered (meaured) outut, g v ) the ( 476

3 ICSE 8 Proc. 8, Johor Bahru, Malaya outut of the etwor, e v ) = y ) g ) the etwor error ( o ad ) the outut of euro wth j μj ) o ) = ex σ g j j j ) = λ ex j σ j j μ ) where dexe the GB ut, j the ut dmeo ad the outut dmeo. IV. SIMULATION ESULTS I th ecto, the oe modelg of Hewlett Pacard HEMT AT-3663 wll be reeted. The modelg doe the frequecy rage (.5-8) GHz. The oe arameter value ued for the trag data are tae from advaced deg ytem (ADS) oftware. The trag et wa obtaed by electg 6 amle. we ued our databae for trag the ANN model wth MATLAB 7..4 rogram. I order to chec the geeralzato caablty, a tet et cotag 45 remaed amle wa ued. Tet ad trag amle mut be dfferet ad are elected radomly from the orgal databae (ADS). I order to comare the accuracy of the model, the maxmum, mmum ad mea relatve error for rooed ANN model wa calculated. Table how the reult for tetg data, where the relatve error for varable X evaluated a X E% = (m) X X(m) (red) Where m ad red tad for ADS mulato (exact value) ad redcted value, reectvely. Alo, the Mea elatve Error evaluated a ME% N = N = E% where N P the umber of ot. Table. The maxmum, mmum ad mea relatve error for tetg data Noe arameter M Max ME m Mag ( Γ ) Ag( Γ ) The comaro of average error (AE %) betwee the tra ad tet data how Table, where the average error for varable X evaluated a N AE % = X(m) X(red) N = It could be ee that the value of AE% le tha.44 %. Table. The average error for trag ad tetg data Noe arameter Trag Tetg m Mag Γ ( ) Ag( Γ ) It oberved from Table ad Table that there a very good agreemet betwee ADS mulato (exact value) ad redcted data. g. how the lot of oe arameter(mmum oe fgure m, ormalzed equvalet retace, magtude of mum reflecto coeffcet Γ ad agle of mum reflecto coeffcet Γ ) veru frequecy ad ba codto, obtaed by the choe model, at two dfferet tate: ()trag of amle ()amle that doe ot belog to the trag et.e., tet et. The comaro betwee ADS mulato ad redcted value of ANN model how that there a excellet agreemet betwee the redcted outut charactertc of the devce baed o our model ad ADS mulato wth leat error. 477

4 ICSE 8 Proc. 8, Johor Bahru, Malaya.5 5 m m.5 Γ Γ Samle g. a Mmum oe fgure m Samle g. b Normalzed equvalet retace amle g. c Magtude of mum reflecto coeffcet Γ Samle g. d Agle of mum reflecto coeffcet Γ V. Cocluo I th aer, oe mortat archtecture of eural etwor amed a geeralzed radal ba fucto aled to model HEMT trator oe arameter uch a mmum oe fgure m, ormalzed equvalet retace, magtude of mum reflecto coeffcet Γ ad agle of mum reflecto coeffcet Γ deedece o ba codto, frequecy ad S-arameter. A alteratve learg rocedure ha bee develoed for the GB etwor. The GB etwor reduce dratcally the umber of ut requred to obta a accurate model. Th etwor ca be deged a hort tme. The comaro betwee ADS mulato ad redcted value of rooed model how that there a excellet agreemet betwee the redcted outut charactertc of the devce baed o GB model ad ADS mulato wth leat error, therefore, the rooed GB model ca be ued a a effcet tool for oe modelg of HEMT trator. EEENCES [] Zlatca Marovć, Vera Marovć, Accurate Temerature Deedet Noe Model of Mcrowave Trator Baed o Neural Networ, 3th GAAS Symoum-Par, (5). [] D. Pozar, Mcrowave Egeerg, J. Wley &So, Ic., (998). [3] Yavuz CENGIZ, lz GUNES, Mehmet ath, Soft Comutg Method Mcrowave Actve Devce Modelg, Tur J Elec Eg, VOL.3, NO.,(5). [4] V.Marovć, Z.Marovć, "HEMT oe eural model baed o ba codto", It. Joural for Comutato ad Mathematc Electrcal ad 478

5 ICSE 8 Proc. 8, Johor Bahru, Malaya Electroc Egeerg- COMPEL, Vol. 3 No., , (4). [5] Z. Marovć, V. Marovć, Neural etwor mcrowave low-oe trator modelg uder varou temerature codto, Proceedg of 6th Semar o Neural Networ alcato Electrcal Egeerg, Belgrade, Serba ad Moteegro,. 99-3, (4). [6] S. Hay, "Neural Networ: A comreheve foudato", Macmlla, Newyor, (994). [7] S.K. Jha, C. Surya, K.J. Che, K.M. Lau, E. Jelecovc, Low-frequecy oe roerte of double chael AlGaN/GaN HEMT, Sold-State Electroc 5, (8). [8] Zlatca Marovc, Vera Marovc, " Predcato of Hemt S Scatterg ad oe Parameter ug Neural Networ ", Mrotalaa revja,. 8-3,(). [9] Aleadar Stoc, Zlatca Marovc, Vera Marovc,"Neural Networ for Noe Modelg of SGe HBT S" Joural of Automatc Cotrol, Uverty of Belgrade, Vol. 6,.5-8, (6). 479