SUBSTRATE integrated circuits provide a convenient

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1 EEE TRANSACTONS ON MCROWAVE THEORY AND TECHNQUES, VOL. 64, NO. 8, AUGUST Mode-Mtching Design of Substrte Mounted Wveguide (SMW) Components Jn Schorer, Grdute Student Member, EEE, Jens Bornemnn, Fellow, EEE, nd Uwe Rosenberg, Senior Member, EEE Abstrct The mode-mtching technique (MMT) is employed to nlyze nd design the trnsition from substrte integrted wveguides (SWs) to substrte mounted wveguides (SMWs) tht re mounted on top nd/or t the bottom of the substrte. Coupling between the lyers is fcilitted by pertures of the thickness of the substrte s metlliztion. By ppropritely segmenting the trnsition, simple nd fst MMT routine is developed. The results obtined for single wveguide resontor mounted on the substrte gree well with simultions in CST nd HFSS nd, thus, vlidte the MMT code. Furthermore, the routine is extended to ccommodte the design of more complex structures. A five-resontor SMW filter with dditionl SW resontors to dd trnsmission zeros nd diplexer re presented nd prototyped. All the mesured results re in good greement with the MMT nd the CST simultion results, thus vlidting the design procedure. ndex Terms Filters, mode-mtching technique (MMT), substrte integrted wveguide (SW), substrte mounted wveguide (SMW), wveguides.. NTRODUCTON SUBSTRATE integrted circuits provide convenient opportunity for integrtion of previously bulky components in single- or multilyered substrte rrngements. Especilly, substrte integrted wveguide (SW) circuitry hs been developed into mture technology over the lst decde [1]. n order to interfce with surfce-mounted ctive components, interconnects to other trnsmission line structures, such s microstrip or coplnr wveguide, re required [2]. To reduce the reltively high losses in microstrip filters operting in the higher gighertz rnge, substrte mounted wveguide (SMW) principle hs been introduced [3]. A K-bnd prototype demonstrtes lower insertion loss nd better electricl performnce tht could not be obtined with plnr microstrip filter structure [4]. Due to the fct tht Mnuscript received October 15, 2015; revised Jnury 27, 2016; ccepted June 3, Dte of publiction July 7, 2016; dte of current version August 4, This work ws supported by the TELUS Grnt in Wireless Communictions. An erlier version of this pper ws presented t the 2015 EEE MTT-S nterntionl Conference on Numericl Electromgnetic nd Multiphysics Modeling nd Optimiztion (NEMO 2015), Ottw, ON, Cnd, August J. Schorer ws with the Deprtment of Electricl nd Computer Engineering, University of Victori, Victori, BC V8W 3P6, Cnd. He is now with Airbus Defence nd Spce, Ulm 89077, Germny (e-mil: schorerj@uvic.c). J. Bornemnn is with the Deprtment of Electricl nd Computer Engineering, University of Victori, Victori, BC V8W 3P6, Cnd (e-mil: j.bornemnn@ieee.org). U. Rosenberg is with Micin Globl Engineering GbR, Bremen 28195, Germny (e-mil: uwe.rosenberg@ieee.org). Color versions of one or more of the figures in this pper re vilble online t Digitl Object dentifier /TMTT SW filter nd diplexer technologies suffer from reltively high insertion losses, the SMW principle lends itself to pplictions in SW. t contributes to the effort to overcome mjor bottleneck of SW technology, nmely, high occurring insertion loss, while mintining fully shielded electromgnetic environment nd high degree of integrtion together with the dvntge of low cost, high volume, production. Therefore, this pper first focuses on severl spects for the design of SMW components. A mode-mtching technique (MMT) pproch to design n SW-to-SMW trnsition is presented, nd the MMT pproch is extended to develop routine for the full-wve design of coupled SMW wveguide filters. These two topics hve been ddressed in [5] nd [6], respectively, where the pproch is successfully used to design the first coupled resontor SMW-on-SW filter [6]. n ddition to [5] nd [6], the MMT is now extended to ccommodte combintion of SMW nd SW resontors in order to crete trnsmission zeros. Moreover, new MMT model is developed to divert the SW input signl into two different SMW components situted in different lyers. Bsed on this model, n SMW diplexer with chnnel filters on top nd bottom of the SW substrte is designed nd prototyped. All extensions of the MMT model re vlidted by simultions in commercilly vilble field solvers nd by mesurements. The overll MMT model will id in the full-wve design of low-loss SMW wveguide filters nd diplexers nd, thus, contribute to the solution of bottleneck in SW technology. Moreover, it is expected tht in n industril fbriction process, SMW prts will be precisely picked nd plced on the printed circuit bord together with ll other components prior to pssing reflow solder process. This pper is orgnized s follows. Section presents the dption of the MMT to SW-to-SMW trnsitions for three different vritions nd highlights the filter design process. Section provides mnufcturing detils nd dimensions of filter nd diplexer prototypes. Section V presents theoreticl nd experimentl results, nd Section V summrizes our findings.. THEORY A. SW-to-SMW Trnsition Fig. 1 shows the side view of n SW-to-SMW trnsition. The SW is coupled to the SMW by n perture in the top metlliztion of the substrte. At certin distnce fter the perture, the SW is shorted using row of vi holes. n the wveguide, the fundmentl TE 10 mode is excited, nd EEE. Personl use is permitted, but republiction/redistribution requires EEE permission. See for more informtion.

2 2402 EEE TRANSACTONS ON MCROWAVE THEORY AND TECHNQUES, VOL. 64, NO. 8, AUGUST 2016 Fig. 1. Fig. 2. Side view of the trnsition between SW nd SMW. Segmenttion of the SW-to-SMW trnsition for MMT nlysis. the distnce to the short is djusted to improve trnsmission performnce. The segmenttion used in the MMT is shown in Fig. 2 nd involves discontinuities in ll three directions. Note tht the subsections re either homogeneously filled with the dielectric mteril of the substrte (or with ir) or re entirely trnsverse to the discontinuities. Therefore, full set of TE mn nd TM mn modes must be considered, but the inclusion of hybrid modes is voided. Following the generl MMT procedure [7], the trnsverse electric nd mgnetic fields in regions nd t their respective boundries with region V re given s E T (z = 0) = q H T (z = 0) = q p Zhq ( )[ hq e z F hq + Bhq ] Zep ( )[ ep F ep + Bep ] = E T (z = c) Yhq( )[ hq F hq Bhq ] + p Zep ( )[ ep e z F ep Bep ] = H T (z = c) (1) where q nd p re the mode indices defining the cross-section functions s T hq m,n = A q cos ( mπ x ) cos ( nπ b y ) 1 + δ0m 1 + δ0n ( nπ ) b y T ep m,n = D P sin ( mπ x ) sin = T hq = T ep (2) where A nd D re the normliztion terms nd δ is the Kronecker delt. Prmeter in (2) denotes the equivlent SW width [8]. F nd B in (1) re forwrd nd bckwrd propgting (or evnescent) wve mplitudes. The wve impednces nd dmittnces re given s Z hq m,n = 1 Y hq Y ep m,n = 1 Z ep ωμ 0 = k0 2ε r ( ) mπ 2 ( nπb ) 2 = ωε 0 ε r k0 2ε r ( ) mπ 2 ( nπb ). (3) 2 The respective fields nd quntities of region t its boundry region V re E T (y = b) = Z ( hr hr e )[ y F hr + ] B hr r H T (y = b) = r s + s Thr i,k = A r Y hr Z es ( )[ es F ( )[ hr F Y es ( es es + B es hr B hr ] e )[ y F cos ( iπ x ) cos ( kπ c z ) 1 + δ0i 1 + δ0k ( kπ T es m,n = D S sin ( iπ x ) sin Z hr i,k = 1 Y hr Y es i,k = 1 Z es ) c z ] es B es ωμ 0 = k0 2ε r ( ) iπ 2 ( kπc ) 2 = ] (4) (5) ωε 0 ε r k 20 ε r ( iπ ) 2 ( kπc ) 2. (6) The fields nd quntities in region V re tken s superposition of those in regions. Then the generlized (modl) scttering mtrix of the three ports is obtined s follows. First, the trnsverse electric fields re mtched t the boundries with the respective other two ports shorted. This results in expressions for the wve mplitudes in region V. Second, mtching the trnsverse mgnetic fields yields the overll scttering mtrix of the junction. The reder is referred to [7] nd [9] for detils. The short t the end of region is incorported using its input reflection coefficient t z = c (Fig. 2) Ɣ = Dig { exp ( j2kzq,p L )} s (7) where k z represents the propgtion constnts in region nd L s is the distnce between z = c nd the short. Assuming tht the generlized scttering prmeter submtrices of the junction re denoted by S ik (i, k = 1, 2, nd 3), then the two-port submtrices between ports nd re S 2p 11 = S 11 + S 12 WS 21 S 2p 13 = S 13 + S 12 WS 23 = S 2pT 31 S 2p 31 = S 31 + S 32 WS 23 = S 2pT 13 S 2p 33 = S 33 + S 32 WS 23 (8) where W = Ɣ( S 22 Ɣ) 1, is the unity mtrix, nd T denotes trnsposed. Once this procedure is estblished, it cn lso be used to nlyze the shorted wveguide junction between ports nd (Fig. 2) by chnging the dimensions nd mteril constnts ccordingly.

3 SCHORER et l.: MODE-MATCHNG DESGN OF SMW COMPONENTS 2403 Fig. 3. Equivlent circuit model for direct-coupled resontor filters. Fig. 5. Segmenttion for the double-lyer SW-to-SMW trnsition. Fig. 4. Segmenttion for the combintion of SW nd SMW resontors. Finlly, the perture of metlliztion thickness t is considered by discontinuity tht includes not only the perture size but lso chnge in wveguide width s for the sme frequency bnd, the wveguide is usully wider thn the SW due to the lck of substrte mteril. The S mtrix representtion of the trnsition in Fig. 2 llows strightforwrd link to theoreticl filter synthesis [10]. By specifying the filter function nd topology, e.g., Chebychev for direct-coupled resontor filters, impednce inverter vlues for different MMT segments cn be synthesized bsed on their S mtrices. Fig. 3 reltes the equivlent circuit model to the wveguide discontinuities for this topology. These impednce inverter vlues, denoted by K n,n+1 in Fig. 3, cn be mtched to theoreticl vlues obtined from stndrd filter synthesis procedures by pplying, e.g., Chebychev polynomils. Note tht the iris in Fig. 2 cts s the first inverter of n SMW filter. The dimensions of the coupling irises re obtined by 1-D optimiztion routine vrying the pertures of the irises. Finlly, the lengths of the resontors seprting the irises re clculted utilizing the inverter phses θ n (Fig. 3). More wveguide pertures nd resontors cn be dded nd designed by stndrd MMT procedures [7]. B. Combintion of SW nd SMW Resontors For the combintion of SW nd SMW resontors, resontor relized in SW technology is ttched to the SW T-junction s shown in Fig. 4. This combintion with SMW resontors on top of the substrte represents filter with n dded trnsmission zero (providing so-clled notch in the combined trnsmission response); lterntively, it cn be considered s n extrcted pole in n overll filter design. The resulting trnsmission zero is used to enhnce the steepness of the filter skirts, thus providing improved selectivity. The SW resontor is fed vi n H-plne iris lso clculted with the MMT. Looking t the segmenttion of this trnsition model (Fig. 4), the electromgnetic clcultion procedure follows the MMT introduced bove. First, the superposition of region V is clculted, nd then different from the clcultion of the previous trnsition from SW to SMW, the SW T-junction is not short circuited by wveguide stub t region, but two pieces of SW seprted by the H-plne iris re dded. This configurtion represents nother impednce inverter in itself, thus llowing the design of this trnsition towrd the theoreticl impednce inverter vlue. The numericl implementtion follows (1) (8), except tht (7) is replced by Ɣ = S i 11 Si 12( + S i 22 ) S i 21 (9) where S i is the modl scttering mtrix of the SW iris including the length of section (Fig. 4), the iris, nd the length of the resontor. C. Double Lyer SW-to-SMW Trnsition A double-lyer trnsition becomes necessry when constructing SMW filter structures with two different brnches to efficiently utilize vilble substrte surfce spce. A possible segmenttion, chosen lter s diplexer circuit, is depicted in Fig. 5. The SW lyer is now relized s four-port junction. Region is the input, region is shortened SW stub, nd regions nd V re the outputs feeding the SMW resontors vi seprte irises. As previously, rectngulr slots in the top nd bottom metlliztion of the SW ct s iris inverters with discontinuities in the E- nd H-plne. Region V is clculted s superposition using the respective fields nd quntities estblished for ech region, V (similr to Section -A). Let S ik (i, k =1, 2, 3, nd 4) be the modl scttering mtrix of the four-port junction, then, by shortening region t distnce L s (7), the three-port scttering mtrix is estblished s 11 = S 11 + S 12 WS = S 13 + S 12 WS 23 = T = S 14 + S 12 WS 24 = T = S 33 + S 32 WS = S 34 + S 32 WS 24 = T = S 44 + S 42 WS 24 (10)

4 2404 EEE TRANSACTONS ON MCROWAVE THEORY AND TECHNQUES, VOL. 64, NO. 8, AUGUST 2016 with Ɣ nd W s in (7) nd (8), respectively. Then djcent double-step irises in the top nd bottom metlliztion re implemented. From this point on, the procedure is similr to the single trnsition of Section -A. Both prmeters re cscded with shortened conventionl wveguide T-junction leding to n overll three-port structure. The modl scttering mtrix representtion of the entire system shown in Fig. 5 is then used to clculte the impednce inverter vlues for the two trnsitions. By implementing 2-D optimiztion routine, it is possible to mtch the impednce inverter vlues to the theoreticl vlues from filter synthesis. This method cn lso be used to design multiport networks. Ech trnsition is treted s strting point for one of two possible brnches of the rchitecture, which then cn be extended in n rbitrry SMW topology on the top or the bottom of the SW.. PROTOTYPES n ddition to the Chebychev design of [6], which will not be repeted here, the design routines estblished bove re pplied to prototype two SMW circuits: 1) coupled five-resontor SMW filter combined with two SW cvity resontors ccording Section -B to introduce two trnsmission zeros; 2) diplexer ccording to Section -C utilizing the trnsition from SW to two SMW lyers feeding the two brnches. Note tht in Design 1, the SW cvities re dded only to improve the ner-bnd rejection of the existing SMW filter [6] with dditionl trnsmission zeros. t is not n extrcted-pole filter, becuse n extrcted-pole filter with seven poles would require n overll design with the SMW component to be reprototyped. Both prototypes re designed for K-bnd pplictions. The vi hole rdius is 0.65 mm, nd the pitch of the vis is 1 mm. The initil MMT design is fine optimized to ccommodte production restrictions using CST. This djustment includes the introduction of the corner rdius for the SMW prts of 1.5 mm. The prototypes re designed on Rogers Duroid/RT 6002 substrte with permittivity of Design 1 is relized in sndwich construction with the following different lyers: the substrte, copper 101 sheet (height of the resontors) with the resontor contour cut into it, nd nother copper sheet cting s lid to the structure. Wire electricl dischrge mchining is used to mnufcture the SMW resontors. t provides n ccurcy of up to 1 2 μm. For the SMW- SW resontor combintion filter, nother metl sheet is plced below the structure to provide even pressure fter ssembly. For the diplexer (Design 2), the sndwich construction structure is mirrored on the bottom of the substrte. The lignment between the different lyers is relized using stinless steel pins. The pressure to hold the structure together is pplied with screws nd nuts. A tolernce nlysis, crried out in [6], hs reveled ±25 μm s n cceptble mrgin for lignment. The conductivity between the different lyers is ensured using conductive silver pste. Bsed on [6], the ccurcy cceptble for the SMW prts is ±10 μm. Fig. 6. Top nd side views of the coupled five-resontor SMW filter with dditionl SW resontors (Design 1). All dimensions re in millimeters. n comprison, the tolernces of the SW prt hve been shown to be the lest sensitive dimensions; this hs lso been reported in [11]. Both prototypes re designed with trnsformer t the SW input port. These trnsformers permit the use of less restrictive iris dimensions, hence less sensitivity of the trnsition, thus enhncing the overll robustness of the prototype design. n the combined SW-SMW filter (Design 1), the SW resontors re used to plce trnsmission zeros on either side of the filter pssbnd. The exct resonnt frequency is determined by djusting the SW iris width nd resontor length in the MMT routine. A sketch of Design 1 prototype including the dimensions is presented in Fig. 6. t shows the SMW prt consisting of the contour nd the lid on the top nd the bottom of the PCB. n Fig. 7, schemtic of the second prototype (Design 2) nd its dimensions re displyed. The double-lyer junction hs been fine optimized using CST Microwve Studio to compenste for the loding effect of the two brnches. This ws not tken into ccount during the initil design. Compred with Design 1, it is necessry to rotte the iris for the second trnsition (SMW to SW) due to spce limittions of the substrte cused by the SW output ports. The trnsition is designed with the MMT by djusting the integrl limits for the mode mtching of the fields. Using the trnsformer together with n iris length oriented in the longitudinl z-direction cuses unwnted higher order resonnces in the trnsformer. Therefore, the trnsformer is removed from the finl design, which cuses slight increse in sensitivity of the output iris. n ddition, the SW fbriction process requires 200-μm distnce for the iris in the z nd x directions in reference to the vi holes. This mrgin is introduced to void deburring t the edges of the vi holes during the PCB process. V. RESULTS n order to verify the MMT code bsed on the theory presented in Section, n SW-to-SMW trnsition is designed for opertion in the 19-GHz rnge. A single TE 10 -mode resontor

5 SCHORER et l.: MODE-MATCHNG DESGN OF SMW COMPONENTS 2405 Fig. 9. Comprison of the results obtined by the MMT with simultions in CST nd HFSS. Fig. 7. Top nd side views of the double-lyer SMW diplexer (Design 2). All dimensions re in millimeters. Fig. 10. Design 1 (substrte prt only) in the test fixture nd clibrtion stndrds (short, through nd line). Fig. 8. Top nd side views of the SW-to-SMW trnsition with dditionl wveguide TE 10 -mode resontor. is dded to the top wveguide to crete significnt frequency sensitivity. Fig. 8 shows the top nd side views of the structure, clerly identifying the different lyers, the coupling perture, the resontor, nd the vi holes in the SW. For given SW nd wveguide widths, the initil perture size, which cts s inverter to the wveguide resontor, is determined by filter theory (see bove), e.g., [10]. The finl vlues s well s the exct positions of the SW nd wveguide shorts re determined by fine optimiztion within the MMT. Fig. 9 shows the results obtined by the MMT nd compres them with simultions in CST nd HFSS. Very good greement is observed in generl. The only discrepncy ppers to be very slight frequency shift of 18 MHz, which mounts to less thn 0.1% t 19 GHz. The devition is ttributed to the fct tht CST nd HFSS simulte the ctul vi holes nd the initil trnsition to n ll-dielectric filled wveguide. The MMT routine considers only the equivlent wveguide width of the SW [8] in view of simple nd fst implementtion. The initil tests hve shown tht depending on implementtion, the MMT code is t lest one order of mgnitude fster thn CST nd HFSS. Thus, the extremely smll devition is cceptble in view of timelier optimiztion nd design process of SMW components. Note tht the dvntge of the MMT over generl field solvers is expected to increse with more complex SMW structures. However, this holds only for structures suiting proper segmenttion nd boundries tht fll long the unit vectors of the coordinte system. For mesurement purposes of Designs 1 nd 2, microstrip trnsitions re designed to feed ll SW ports. Such trnsitions re de-embedded by performing TLR clibrtion of the vector network nlyzer (VNA). The clibrtion stndrds (Fig. 10) required for this procedure re custom mde, plcing the mesurement reference plnes (the red dshed lines in Fig. 10) t the beginning of the SW shown in Figs. 6 nd 7. Fig. 11 shows the mnufctured prototype components of the filter (Design 1). The bottom prt shows the SW with the coupling slots nd microstrip trnsitions t opposite sides. Fig. 12 presents comprison between the simulted nd mesured results of the SMW filter with two SW resontors (Design 1). n ddition, mesurements of directly coupled five-resontor filter without SW resontors, s presented in [6], re included for comprison [Fig. 12()].

6 2406 EEE TRANSACTONS ON MCROWAVE THEORY AND TECHNQUES, VOL. 64, NO. 8, AUGUST 2016 Fig. 11. View of the mnufctured prototype (Design 1) with SMW sndwich prt (top) nd SW (bottom). Fig. 13. View of the mnufctured diplexer prototype. Left: SMW sndwich prts. Right: top nd bottom view of SW. Fig. 12. Design 1: comprison of the results obtined by the MMT/CST with prototype mesurement dt. () Nrrowbnd. (b) Widebnd. For the S 11 prmeter, good greement between simultions nd mesurement is obtined. A mrginl wider bndwidth in the mesurement is observed, resulting in slightly smller rejection increse t the filter s cut-off frequencies, especilly visible t the lower one. This is cused by the verticl lignment ccurcy of the sndwich construction (see [6]). Reflection zeros re observed t identicl frequencies for the lower pssbnd, slightly incresingly deviting between mesurement nd simultion towrd the upper pssbnd. The mgnitude of the ripples in the pssbnd is bit higher for the mesured dt, but well within the expected mesurement ccurcy regrding the sndwich construction. As for S 21, the simulted nd mesured dt in the pssbnd devite by 1 2 db. This is mostly due to higher conductor losses cused by the connectivity between the sndwiched lyers nd possible oxidtion of the prototypes surfces. For the trnsmission zeros cused by the SW resontors, smll shift in frequency between simultion nd mesurement is observed. The zero t the higher frequency devites by pproximtely 100 MHz. Nevertheless, both trnsmission zeros re well developed, demonstrting the intended use to obtin extr notches nd thus improving the selectivity of the existing five-pole filter. This is clerly shown when the mesurement of this component (Design A) is compred with tht of the directly coupled five-resontor filter without SW resontors s presented in [6]. The mesured insertion loss levels of the two filters devite by bout 1 db. The simultion dt do not imply different Q vlues for the single SMW resontors. Therefore, this discrepncy is ttributed to mesurement inccurcy. Fig. 12(b) shows widebnd simultion confirming tht there re no spurious unwnted resonnces over the rest of the K-bnd. Fig. 13 shows the mnufctured prototype of the diplexer (Design 2) in disssembled stte. Since two SW circuits hve been fbricted, their top nd bottom views re shown in Fig. 13 (right). The two SMW filters [Fig. 13 (left)] re mounted on the top nd bottom metlliztion s shown in Fig. 7. A comprison between the mesured nd simulted results is displyed in Fig. 14(). n generl, good greement between simultion nd mesurement is observed with distinct seprtion between the two frequency bnds. A devition between the computed nd mesured selectivity is observed t rejection levels below 40 db. This is ttributed to the obtinble ccurcy using clibrtion stndrds to deembed the cox-to-microstrip-to-sw trnsitions. After clibrtion, mesurement of the line clibrtion stndrd reveled S 11 vlue between 40 nd 45 db (not shown here), which cn be tken s the minimum level of mesurement ccurcy. Similr discrepncies below 40 db re observed for the T-junction SW diplexer in [12]. As for the S 11 prmeter, the mesured pssbnds re slightly wider thn those obtined from the simultion. The steepness of the lower skirt selectivity of the upper bnd lmost mtches the simultion dt. The other skirts re slightly off, where the widening of the lower frequency bnd is more pronounced thn tht of the upper one. The slight devitions in the positions of the reflection zeros re lredy known from the tolernce nlyses presented in [6].

7 SCHORER et l.: MODE-MATCHNG DESGN OF SMW COMPONENTS 2407 V. CONCLUSON An MMT for the nlysis nd design of SMW components on SW technology is presented. The method is rigorous nd includes the metlliztion thickness of the perture. The specific segmenttion of discontinuities in the MMT permits the use of regulr wveguide TE mn nd TM mn modes. The results obtined for single resonnt structure, which consists of the SW-to-SMW trnsition nd n dded wveguide TE 10 -mode cvity, shows very good greement with CST nd HFSS simultions. Furthermore, the results for the combintion of SW nd SMW resontors demonstrte good greement between MMT/CST nd mesurements, thus not only proving the vlidity of the MMT pproch but lso presenting design for highly selective bndpss filters. The mesured results of more complex diplexer structure show good greement with simultions obtined from MMT/CST. The MMT models presented here hve proven to be vlid nd fst routines for the timely optimiztion nd initil design of different SMW components. They fcilitte n efficient wy to design combined SW SMW, low-loss, pssive, nd frequency-selective systems. Fig. 14. Design 2: comprison of the results obtined by the MMT/CST with prototype mesurement dt. () Nrrowbnd. (b) Widebnd. Therefore, they re ttributed to mnufcturing inccurcies. The return loss ripples re mrginlly higher, bout 2 3 db, for the mesured dt, nd re well within the expected devition. The sme widening in bndwidth is observed in the mesurements of the two pssbnd trnsmission prmeters S 21 nd S 31. The mgnitude level flls bout 1 2 db short of the simultion. This ws lredy observed in the previous prototype (Design 1) nd is likely cused by the introduction of losses due to connectivity issues nd surfce oxidtion. Therefore, the expected Q vlues of the prototyped diplexer nd Design 1 re within the rnge of those presented in [6]. A ripple in the pssbnd for the S 21 nd S 31 insertion loss prmeters is observed. These ripples cn be ttributed to mesurement nd clibrtion inccurcies. These re likely cused by the movement of cbles nd the test fixture while switching from the clibrtion stndrds to the DUT. Other mesurement inccurcies re relted to issues cused by the termintion of the third unused port when mesuring with two-port VNA. Fig. 14(b) shows wider section of the K-bnd. This simulted dt demonstrte tht the diplexer does not exhibit ny other spurious resonnces. The current design successfully suppresses ll signls in the rest of the K-bnd. Focusing on insertion loss, SMW technology provides significnt improvement when compred with similr pure SW circuits. For exmple, filter similr to Design 1 (Fig. 6), but without the dditionl SW resontors, exhibits Q vlue tht is roughly four times higher thn the one of comprble SW filter [13]. REFERENCES [1] K. Wu, Stte-of-the-rt nd future perspective of substrte integrted circuits (SCs), in Workshop Notes, EEE MTT-S nt. Microw. Symp. Dig., Anheim, CA, USA, My 2010, pp [2] F. Tringou, J. Bornemnn, nd K. Wu, Brodbnd coplnr-wveguide nd microstrip low-noise mplifier hybrid integrtions for K bnd substrte integrted wveguide pplictions on low-permittivity substrte, ET Microw., Antenns Propg., vol. 8, pp , Jn [3] W. Menzel nd M. Wetzel, Wveguide filter integrted into plnr circuit, in Proc. 32nd Eur. Microw. Conf., Miln, tly, Sep. 2002, pp [4] T. J. Müller, W. Grbherr, nd B. Adelseck, Surfce-mountble metlized plstic wveguide filter suitble for high volume production, in Proc. 33rd Eur. Microw. Conf., Munich, Germny, Oct. 2003, pp [5] J. Schorer nd J. Bornemnn, A mode-mtching technique for the nlysis of wveguide-on-substrte components, in Proc. EEE MTT-S nt. Conf. Numer. Electromgn. Multiphys. Modeling Optim. (NEMO), Ottw, ON, Cnd, Aug. 2015, pp [6] J. Schorer, J. Bornemnn, nd U. Rosenberg, Design of surfce mounted wveguide filter in substrte integrted wveguide technology, in Proc. 45th Eur. Microw. Conf., Pris, Frnce, Sep. 2015, pp [7] J. Uher, J. Bornemnn, nd U. Rosenberg, Wveguide Components for Antenn Feed Systems: Theory nd CAD. Norwood, MA, USA: Artech House, [8] Z. Kordiboroujeni nd J. Bornemnn, Designing the width of substrte integrted wveguide structures, EEE Microw. Wireless Compon. Lett., vol. 23, no. 10, pp , Oct [9] E. Kühn, A mode-mtching method for solving field problems in wveguide nd resontor circuits, AEU-nt. J. Electron. Commun., vol. 27, pp , Dec [10] G. Mtthei, L. Young, nd E. M. T. Jones, Microwve Filters, mpednce-mtching Networks, nd Coupling Structures, Dedhm, MA, USA: Artech House, [11] A. B. Aly, M. Bozzi, L. Perregrini, N. Rveu, nd K. Wu, Comprison of fbriction tolernce sensitivity between substrte integrted wveguide nd microstrip circuits, in EEE MTT-S nt. Microw. Symp. Dig., Phoenix, AZ, USA, My 2015, pp [12] Z. Kordiboroujeni, J. Bornemnn, nd T. Sieverding, K-bnd substrte integrted wveguide T-junction diplexer design by mode-mtching techniques, in Proc. Asi Pcific Microw. Conf., Sendi, Jpn, Nov. 2014, pp [13] J. Schorer, J. Bornemnn, nd U. Rosenberg, Comprison of surfce mounted high qulity filters for combintion of substrte integrted nd wveguide technology, in Proc. Asi Pcific Microw. Conf., Sendi, Jpn, Nov. 2014, pp

8 2408 EEE TRANSACTONS ON MCROWAVE THEORY AND TECHNQUES, VOL. 64, NO. 8, AUGUST 2016 Jn Schorer (GSM 14) received the bchelor s degree in electricl engineering nd informtion technology nd the mster s degree in electricl engineering from the University of Applied Sciences Rvensburg Weingrten, Weingrten, Germny, in 2010 nd 2012, respectively, nd the Ph.D. degree from the University of Victori, Victori, BC, Cnd, in He hs been with the Computer-Aided Design of Microwve ntegrted Circuits Group, Deprtment of Electricl nd Computer Engineering, University of Victori, since Since April 2016, he hs been with Airbus Defense nd Spce, Ulm, Germny. Jens Bornemnn (M 87 SM 90 F 02) received the Dipl.-ng. nd Dr.ng. degrees in electricl engineering from the University of Bremen, Bremen, Germny, in 1980 nd 1984, respectively. He ws Consulting Engineer from 1984 to n 1985, he becme n Assistnt Professor with the University of Bremen. He hs been with the Deprtment of Electricl nd Computer Engineering, University of Victori, Victori, BC, Cnd, since 1988, where he becme Professor in He ws Fellow of the British Columbi Advnced Systems nstitute, Vncouver, BC, Cnd, from 1992 to n 1996, he ws Visiting Scientist with Spr Aerospce Limited, Ste-Anne-de-Bellevue, QC, Cnd, nd Visiting Professor with the Microwve Deprtment, University of Ulm, Ulm, Germny. He ws Co-Director of the Center for Advnced Mterils nd Relted Technology with the University of Victori from 1997 to He ws Visiting Professor with the Lbortory for Electromgnetic Fields nd Microwve Electronics, ETH Zurich, Zurich, Switzerlnd, in He co-uthored Wveguide Components for Antenn Feed Systems: Theory nd Design (Artech House, 1993) nd hs uthored/couthored over 300 technicl ppers. His current reserch interests include rdio frequency/wireless/microwve/millimeter-wve components nd systems design, nd field-theory-bsed modeling of integrted circuits, feed networks, nd ntenns. Dr. Bornemnn is Fellow of the Cndin Acdemy of Engineering nd member of the Europen Microwve Assocition. From 1999 to 2002, he served s n Associte Editor of the EEE TRANSACTONS ON MCROWAVE THEORY AND TECHNQUES in the re of microwve modeling nd CAD. He served on the Technicl Progrm Committee of the EEE MTT-S nterntionl Microwve Symposium from 1999 to He ws n Associte Editor of the nterntionl Journl of Electronics nd Communictions from 2006 to He serves on the Editoril Advisory Bord of the nterntionl Journl of Numericl Modeling. He is Registered Professionl Engineer in the Province of British Columbi, Cnd. Uwe Rosenberg (M 89 SM 93) received the Dipl.-ng. degree (Hons.) in electricl engineering (with minor in telecommuniction technique) from the Fchhochschule der Deutschen Bundespost, Dieburg, Germny, in He ws with Hydro Therm, Dieburg, Germny, from 1982 to 1983, where he ws involved in the design nd development of utomtic sfety nd heting control circuits. He ws with the Technische Hochschule Drmstdt, Drmstdt, Germny, from 1983 to 1985, where he ws involved in the design nd development of experimentl instlltions nd softwre components for microcomputer control systems. He joined the Spce Division, Test- Spcecom GmbH & Compny KG, Bcknng, Germny, in 1985, where he ws involved in the reserch nd development of microwve filters, multiplexers, nd pssive subsystems for communictions stellites. From 1989 to 2008, he ws the Hed of the Reserch nd Development Lbortory for Pssive Microwve Components nd Subsystems with Ericsson GmbH, Bcknng (which ws, until December 2005, Mrconi Communictions GmbH nd formerly Bosch Telecom GmbH, Public Networks Division). During this period, he ws in chrge of reserch nd development of integrted wveguide trnsceiver circuitries, chnnel brnching networks (multiplexers), ntenn feed nd wveguide (feeder) systems for trunk nd ccess rdio pplictions, mobile bse sttions, lrge erth sttions, nd defense nd communictions stellites. He ws ppointed s Mnger of the Antenn Development Tem from 2006 to n 2002, he strted his own project nd consultncy work for interntionl compnies with the design of novel pssive microwve designs nd subsystems for vriety of pplictions (erth sttions, stellites, millimeter-wve communictions equipment, mobile, nd defense) providing design, mesurement, production, nd technology support nd dvice. He hs been the Mnging Director of Micin Globl Engineering GbR, Bremen, Germny, since 2011, which he co-founded the sme yer together with prtners. He co-uthored Wveguide Components for Antenn Feed Systems: Theory nd CAD (Artech House, 1993). He hs lso uthored or co-uthored over 100 technicl ppers nd hs originted more thn 50 grnted microwve design ptents. Mr. Rosenberg is Member of the Verbnd der Elektrotechnik Elektronik nformtionstechnik, the nformtionstechnische Gesellschft, nd the Verein Deutscher ngenieure. He is lso Member of the Europen Microwve Assocition nd Senior Member of the EEE Microwve Theory nd Techniques Society nd the EEE Antenns nd Propgtion Society.