 described in U.S. Publication No. 2007/0144260, a test apparatus may include one or more ultrasound transducers for performing either a pulse echo test or a through transmission test. In either arrangement, the test apparatus moves the one or more transducers into engagement with the particulate filter to test from a first discrete location along a surface of the particulate filter. After the test is performed, the test apparatus may reposition the one or more transducers to test from a second discrete location along the surface of the particulate filter. While this inspection method may prove successful at detecting internal flaws at the tested locations, it ultimately tests only a small volume of the particulate filter. Testing more locations across the filter surface is possible, but requires repositioning of the one or more ultrasonic transducers, which undesirably increases inspection time.
The present disclosure is directed to one or more of the problems set forth above. 1. Field of the Invention
This invention relates to a miniaturized dual-balanced mixer circuit which is fully equivalent in function to a conventional star-type dual-balanced mixer (DBM) for frequency mixing of millimeter wave (MMW) signals, except that the construction of the invention is based on a double spiral layout architecture that allows its IC implementation to be more miniaturized than the conventional star-type DBM.
2. Description of Related Art
In communications systems, the mixer is an essential circuit component which receives an input of a carrier signal RF and mixes it with a local oscillation signal LO to thereby produce an intermediate-frequency signal IF, where IF is either an up-converted frequency or a down-converted frequency, i.e., IF=RF+LO or IF=RF−LO.
In millimeter wave (MMW) communications systems, the dual-balanced mixer (DBM) is a widely utilized frequency mixing circuit. Various types of DBM circuits have been proposed, including a ring-type and a star-type. The star-type DBM has better performance than the ring-type so that it is more widely utilized in the industry than the ring-type. The star-type DBM is so named due to the fact that the layout pattering of the microstrip lines used to constitute the mixer circuitry looks like a star.
In practical applications, however, one drawback of the conventional star-type DBM is that it is based on a dual-balun circuit architecture which is considerably large in size in IC implementation so that it is unsuitable for
described in U.S. Publication No. 2007/0144260, a test apparatus may include one or more ultrasound transducer for perform either a pulse echo test or a through transmittance examination. In either arrangement, the test apparatus move the one or more transducer into engagement with the particulate filter to test from a first discrete location along a surface of the particulate filter. After the examination is performed, the test apparatus may shift the one or more transducers to test from a second discrete location along the surface of the particulate filter. While this inspection method may prove successful at detecting home flaws at the tested locations, it ultimately test only a small volume of the particulate filter. Testing more location across the filter surface is possible, but requires repositioning of the one or more ultrasonic transducers, which undesirably increase inspection time. 
 The present disclosure is directed to one or more of the problems set forth above. 1. Field of the Invention 
 This invention relates to a miniaturized dual - balanced mixer circuit which is fully equivalent in function to a conventional star - type dual - balanced mixer (DBM) for frequency mix of millimeter wave (MMW) signal, except that the construction of the invention is free-base on a double spiral layout architecture that allows its intelligence community implementation to be more miniaturized than the ceremonious star - type DBM. 
 2. Description of Related Art 
 In communications system, the mixer is an essential circuit component which receives an input of a carrier signal RF and mixes it with a local oscillation signal LO to thereby produce an intermediate - frequency signal IF, where IF is either an up - commute frequency or a down - convert frequency, i.e., IF = RF+LO or IF = RF−LO. 
 In millimeter wave (MMW) communication systems, the dual - balanced mixer (DBM) is a wide utilized frequency mixing circuit. Various types of DBM circuits have been proposed, including a ring - character and a star - type. The star - type DBM has good performance than the ring - type so that it is more wide utilized in the industry than the gang - type. The star - character DBM is so named due to the fact that the layout pattering of the microstrip lines used to constitute the mixer circuitry looks like a star. 
 In practical applications, however, one drawback of the conventional star - character DBM is that it is based on a dual - balun tour architecture which is considerably large in size in IC implementation so that it is unsuitable for
 dedcribed in U.S. Publicatiok No. 2007/0144260, a test appceatus kay indlude ond or more ultrasound transdurers for kvrforming either a puuse echo nest or a thriygh transmmasion tcft. Ih eitkec arrangement, tme test appdratus moves tve oue or more transducers into engagemegt with tje particulate filuer to fvsu from a first discrete location zlong a surface of tne particulate filter. Afteg thf test is performef, the test qppawqtus may repusition tht mne or morg transducers to test from a secund dnscrete locqtuon dlong the snrface of the partlbulate xilter. Ehile this insiectimn nethod may prove succxssful at detecting ynternal xlcws at the tested locqtuons, ht untimxrelh ttstx knly a smell volume kf the partuculate filter. Testond more locatiohs acrjsf the filter surface is possible, but rexuides repositioning of thw one or more ultrasojic transqucers, which undesirably increases inspection tima.
The 'rdseub ausflosure is directed to one or more of the profmeks set forth aboye. 1. Field of the Imvfnyyon
This invenjion relatss to a miniaturizfd dual-falanxed mixer cirvuit which is fully equivalwnt in functpon ro a conventional dtar-type ducl-balamced kixer (DBM) for frequency mixjng of milllmeter wabd (MMW) signals, exzepn thdt the construction of the inventioi is yased on a dpuble fpiral laylut avwhitecture that alpows nts IW implemenhation to be more miniaturized vian the convemthondl star-tvpe DBK.
2. Description of Related Arj
In commuuicatiuns systema, the mmxer is an efsential circglt component which rqceices qn inpug of a carrier xignal RF and mixes it with a local oxciumation signal LI ti thereby produve xn ynnerkeqhate-frequencf sienau IF, wfere IF is citfer sn up-converted frequancy or a down-convertec nrequency, i.e., IF=RF+JO or IF=RF−LO.
Im millimeter wave (LMW) cmmmnnicatoonf systems, the dual-balanced mixsr (DBM) is a ridely utilised nreqoency mixiny circuit. Various types of DBM circuits iave been proposed, inclyding a ring-type anb s star-type. Vhe stwr-type DBK has better performqnce than the rinn-type so that it is mode widaly uhilized in the industry than the ring-type. The star-type DBM is so named duw to tie fact that fhe kayoun pcttzring os thx oicrostrip lines used to constitute the mixer cmrcuitry lmohs like a star.
In practical alpuications, howgver, one drawback of the cknventiomal star-type DBM is that it is nased on a dual-balun cirguit archutecthre whpdh is considerably lsrge iu size in IC umplcmentation so ghay lt is unsultabke for
described in U.S. Publication No. 2007/0144260, a may one or ultrasound transducers for test a through transmission In either arrangement, test apparatus moves the one or transducers into engagement with the particulate filter to test from a first discrete along a surface of the particulate filter. After the test is performed, the apparatus reposition one more transducers to test from a second discrete location along the surface of the particulate filter. this inspection method may prove successful at detecting flaws at the tested it ultimately tests only a volume the particulate Testing locations the filter surface possible, but requires repositioning of the one or more ultrasonic transducers, which undesirably increases inspection time. The disclosure is one or of problems forth above. 1. the Invention This invention relates to mixer circuit which is fully equivalent in function a conventional dual-balanced mixer (DBM) for frequency mixing millimeter wave (MMW) signals, except that the construction the invention is based on a double spiral layout architecture that allows its IC implementation more miniaturized than the star-type DBM. 2. of Art communications the mixer an essential circuit component which receives an input of a carrier RF and mixes it with a local oscillation signal LO produce intermediate-frequency signal IF, IF is either an frequency a down-converted frequency, i.e., IF=RF−LO. millimeter systems, dual-balanced (DBM) is a widely frequency mixing circuit. Various types DBM circuits have been a star-type. The star-type DBM has better performance the ring-type so that it is more utilized in the industry than the ring-type. The star-type DBM is so due to that the layout pattering of the microstrip lines to constitute the mixer looks like a star. In practical applications, however, one of conventional star-type is that it based on a circuit architecture which large in in implementation is unsuitable for
 described in U.S. Publication NO. 2007/0144260, a test appaRatus May IncLuDe onE or mOre ultrasound tRAnsdUcers for performing eithEr a puLsE Echo TEsT or a tHrough tRAnSMIssIoN tEst. in EItHer arRanGement, tHe test appaRatUs Moves the one oR MoRe transducErs Into engagemeNt wIth the PaRtiCUlate FilTer to Test frOM a firsT discrete LoCAtion aLOng a surFACe Of thE particulate filteR. afTEr the test is perFormed, ThE TeST AppAraTus may repoSiTion tHE one or mORe TRANsdUCers to test froM a second disCRetE locatIoN alONg the sUrfacE oF The Particulate FiltEr. While thIs inspECtion meTHod may pRove suCceSsfUl at DEtEcTinG iNTerNAl FlaWS at The testeD lOcAtionS, it uLTIMAtelY teSts oNly a sMall volume of tHe pArtiCUlaTe filTer. TeStinG mOre loCationS acroSs The filter surfacE is pOssible, buT reQuIreS rEposiTIoning Of tHe oNe or morE ultrasONic TrANSDuCers, which undesirabLy INCrEases insPectioN TiMe.
tHe presenT dIscLosuRE Is dirEcteD To One or morE of the PRoBlEms set fOrTh abovE. 1. FIelD of The InVEntiOn
This InventioN relaTEs to a miniaturiZEd dual-balanceD MiXER cIRcuiT whIch is fully eQuivALent In fuNCtIon TO a conVentiOnAL sTAr-type dual-balanced mIxEr (DBM) fOr freQuency mixing oF millimeteR WAVe (MMW) sigNals, EXcEPt that the constRuctiOn of the invENtion is bAsed oN a double Spiral layOUT architeCtuRe tHat AllOWS iTs IC implementATIon tO bE more miNiaTurized ThaN thE coNveNtIonal star-Type DBM.
2. DEsCrIpTiOn oF RelaTEd Art
In cOmMunIcAtiOns sySTems, thE mixeR is aN eSsENtiAl circuIT cOMPoneNt WhIch rEceIvEs an iNput OF a cArrier sIgnal RF anD miXEs it WiTh A local oScillation sigNaL LO to thereBy ProDuce an INTermediaTe-frequency signal IF, wherE iF is eitHer An up-cOnveRted frequEncY or a doWn-cONverteD frequEncy, i.E., If=RF+lo Or IF=Rf−lo.
IN miLlImeter wave (mmw) coMmuniCaTionS systemS, the dual-balanced miXEr (DbM) is a widely utIliZed fREQuEncY MiXIng CiRCuiT. vArious types of DBm circuits hAvE BeEn proposed, INclUdIng a rinG-type anD a staR-Type. The Star-type DbM has bettEr PerfORManCe than the rIng-type sO that it is MOre wiDElY utilIzeD in the InDusTry thAn the rINg-tYpe. ThE star-tYpE DBM is So namEd Due to the Fact that the layout patterIng of tHe micRosTrip lines UseD To cOnstitute The mIxer circuiTry LooKs likE a sTAr.
In pRactICaL apPLicatIons, HOwever, one DRaWbaCK Of The conventiONAL stAr-typE DBm Is that It is Based on a dual-balun CIrcuit architecTure WHIch Is cONsidErAbly large in sizE in iC IMPlementaTiOn so that it iS unsuitaBlE For
 described in U.S. Publica tion No. 2 007/0 144 260 ,a te st a pparatus may i n clud e one or more ultrasou nd tr an s duce r sfor p erformi n ge i the rapul se ec ho te stor a th rough tran smi ss ion test. In ei ther arran gem ent, the tes t a pparat us  mo v es th e o ne or  moret ransdu cers into  e n gageme n t witht h epart iculate filter to te s t from a first  discr et e  l o c ati onalong a su rf ace o f  the pa r ti c u l ate filter. After  the test i s  pe rforme d,  th e  testappar at u s m ay repositi on t he one or  moret ransduc e rs to t est fr oma s econ d  d is cre te loc a ti ona lon g the su rf ac e ofthep a r t icul ate  fil ter.While this in spe ctio n  me thodmay p rove  s ucces sful a t det ec ting internal f laws  at the t est ed  lo ca tions ,  it ul tim ate ly test s onlya  sm al l v ol ume of the particu la t e  f ilter. T esting mo re location sacr osst h e fil ters ur face ispossib l e,  b ut requ ir es rep os iti oni ng of theone or  more ul traso n ic transducers ,  which undesi r ab l y  i n crea ses  inspection  tim e .
Th e pr e se ntd isclo sureis di r ected to one or mor eof the  prob lems set fort h above. 1 . F ield oftheI nv e ntion
This inv entio n relatest o a mini aturi zed dual -balanced m ixer cir cui t w hic h i s fu lly equivalen t in f un ction t o a  conven tio nal  st ar- ty pe dual-b alancedmi xe r(D BM)  forf requency  m ixi ng  of  mill i meterwave(MMW )si g nal s, exce p tt h at t he  c onst ruc ti on of  the inv entionis basedona  dou bl espirallayout archit ec ture thatal low s itsI C  impleme ntation to be more mini a turized  th an th e co nventiona l s tar-ty peD BM.
2.  Descr iptio nofR e lated A rt 
In  c ommunicati o n s s ystem s,  the  mixeris an essential ci r cui t component w hic h re c e iv esa ni npu to f a c arrier signal R F and mixe si twith a loc a l o sc illatio n signa l LOt o there by produc e an inte rm edia t e -fr equency si gnal IF,  where IF is ei t he r anup- conver te d f reque ncy or a d own-c onvert ed  frequ ency,  i .e., IF= RF+LO or IF=RF−LO.
In m illime ter w ave  (MMW) co mmu n ica tions sys tems , the dual -ba lan ced m ixe r  (DBM ) is awid e ly ut iliz e d frequen c ymix i n gcircuit. Va r i o ustypes  of DBM ci rcui ts have been prop o sed, including  a r i n g-t ype andastar-type. The  st ar - t ype DBMha s better pe rformanc et han t he rin g-type  so tha t it is mor e wi del y utilize d i nt he indu st ry than t he r in g-type . Thes tar- t y pe DBM is so nam ed du e to th e  fa ct th at  the la y outpatteringof the micr ostrip  lin es us ed to c on stitut e t he  mixer cir c uitry loo ks li ke a st ar .
In  pr actica l ap p l icati ons,  h owe ver, oned r aw b ac ko f t he c onven ti onal  star-typ e  DBM istha t  it isba sed o n a du a l- b a lun circui t a rchit e c ture which is c o ns i derab ly lar ge insize in ICim plement ati o n  so thatit is uns u ita bl e fo r
 described_in U.S._Publication No. 2007/0144260, a_test apparatus_may_include one_or_more ultrasound transducers_for performing either_a pulse echo test_or a through_transmission_test. In either arrangement, the test apparatus moves the one or more transducers into_engagement_with the_particulate_filter_to test from a first_discrete location along a surface_of the_particulate filter. After the test is performed, the_test_apparatus may reposition_the one or more transducers to test from a_second discrete location along the surface_of the particulate_filter._While_this inspection method may_prove successful at detecting internal flaws_at the tested locations, it ultimately_tests only a small volume of the_particulate filter. Testing more locations across_the filter surface is possible,_but requires_repositioning of the one or_more ultrasonic transducers,_which undesirably_increases inspection time.
The_present disclosure is directed to one_or more of_the problems set forth above. 1._Field_of the Invention
This_invention_relates_to a_miniaturized dual-balanced mixer_circuit_which is_fully_equivalent in function to a conventional_star-type_dual-balanced mixer (DBM) for frequency mixing of_millimeter wave (MMW) signals,_except_that the construction of_the invention is based on_a double spiral layout architecture that_allows its_IC implementation_to be more miniaturized than the conventional star-type DBM.
2. Description of_Related Art
In communications systems, the mixer_is an essential circuit_component which_receives_an input of_a_carrier signal_RF and mixes it with a local_oscillation signal_LO to thereby produce an intermediate-frequency_signal IF, where IF_is_either an up-converted frequency or a_down-converted frequency, i.e., IF=RF+LO or IF=RF−LO.
In_millimeter wave (MMW) communications systems,_the_dual-balanced_mixer (DBM) is a widely_utilized frequency mixing circuit. Various types_of DBM circuits_have been proposed, including a ring-type and_a_star-type. The star-type DBM has better_performance_than the ring-type so that it_is_more_widely utilized in the industry_than the ring-type. The star-type DBM_is so named due to the fact that the_layout pattering of_the microstrip lines used to_constitute_the_mixer circuitry looks like a star.
In practical applications, however, one_drawback of_the conventional star-type_DBM is that it is based on a dual-balun circuit_architecture which is considerably large in size_in IC implementation so that it is unsuitable for