PIi. Coquct: Alsu wilh Communications ltcrcarch Lahoratory, Minislt-y or Posts and Tclccomnimiications, Kognnei-shi, Tokyo 184- 8795, Japan
Rcfccrciicw
~.I,IIKANI)P.S, c.A., and FERNANDES, J G . : 'Pcrrurmnnce o r lens antcmnas in wirelcss indoor inillimctzr-wnvc npplicatiotis', I t Trnns.. 1999, MIT-47, (61, pp. 732-737
antcnna using hi-laycr Butler matrix circuils'. Proc. ISAP'96, Cbilra, kipan, I W G , Vol. 1, pp. 145-168
ELEFTHBRIADES, G,\'., I I R A N I I . Y . , XlJKUII'II. J L K , and hlOSI0. J.11,: 'ALPSS: n millinietre-wavc xpcrturc-conplcd patch antcnnn on H
s:ubslrMe lens', E k c r r i l , Lcu.. 1997, 33, (3), pp. I69 -I70 gnus5ian bcain aiitciina and iiitegrtiiion w i h planar circuits'. lREE
M'JT-S l n t . Synip. Dig., 1496, Vol. I , pp. 393-396
R A I J I H R I J . , R.: 'Etude de rtuonateurs de Phot-Fnbry et cl'anteiincs
impriiiides en ouiles millini8triqiies. Conccption d'aiitcnncs B raisceau gaassicn'. 7'1113 'I'hcsis, liciiiics University, Dccenibcr 1999
CL'LLCN, A.I.., and Y U . P.K.: 'C;oinplcx sourcc-point theory of the clccimmagnctic opcn resonator', Puoc. X. Sua I..and A., 1979,3h6, pp. 155 -171
M A i P V I , I,,: 'ImplcInciitation of conductor losses in FnTD algorithm coinbiiieil with Floquel boundnry conditions. Applicalioil lo the study of niillimctcr wavcq rcsonant cavities',
Mtrrow. Opr. 7 k d I / d L c l i . . 1999, 22, (Z), pp. 103-108
SItKI, 'I., IJb'IIAI<A, K., and KAGOSHIMA, K.: '30.GIIz iniiltibeain
MI\'I'YUI. T I KIYOKAWR. M., ;LIld IIIROSB, N.: 'Milliineler N I W
SAULKALI, K., ' L I I O U I ~ O U I ~ P , D., COW!kT. P H I DANIEL. J,l',, tll>d
Beam-switchable
s a n n
ing
lea
ky-wave
antenna
Chien-Jen Wnng, Yiag-Chou Shih and C.F. Jou
A bcain-switdlal~llc scmming leaky-wwe mteniia (t>WA) has Imn developed. 711is LWA with a two-tcrminnl fccding microstrip line structiii'c is intcwited with H siogll: port double ihroru (SPDT) switch 21s II control circuit. [n dual-hcarn modc, the smiining nnglc is stocrcd owr ;1 wngc of 36 64' for the right-hxod h i m niid 144 -116" for the left-hand beam. In one-beam mode, the .%inning siigle is measntd owr 20" for tlic right-11:ind bciim. The
ineasuretl r d i sliows that wc c m chnngc froiin the ordxium
mode to tlic dual-kain inodc cl~ctroni~illy by controlling Ihe on/ off statiis of mi SPDT swikh, in coiilrasl to the casc for lrarlilional leaky-rmvc a n t c t u w .
htruiiuczion: Lcaky-wave anteiiiias (L WAS) t w e recently attracted a signiticant degrcc of intcrcst, and the iisc or varioiis
types of Icaky-wavc antcnna as rrcq ueng-smrming eletuents is incrcasiiig [1 - 41. Lenky-wave antennas possess tlie adviint;igcs of
having a low profilc, bciug simple to fabricate, ease of matching, having it 1111crow bcamwidth and rrequency-sc*innitig capability. Thcy iirc d s o highly suitable Tor use as active integratcd inillimc- trc-wdw i 111 lcnnas.
One-beam scanning leaky-wave antennas [ 1, 21 and dual-beam scatitling leaky-wave antennas [3, 41 have bcen widcly studicd. Unfortunately, no method has yet bccn proposcd which cin ena- hle the beam mode, such as thc onc-bcnm scanning or dual-beam scanning inodc, to bc cliangcd.
In this Letter, we present a one-beaddudheam watining Iciiky-wuve nnkiiiia (see Fig. I> design. A two-tcrinind fccding
LWA is intcgratcd with it single port double throw (SPTIT) con- lrol circuit, shown iii Fig. 2. The radiation pattern m n
bc
switched betwcen oncbcim modc and dual-btm mode by cliang-
ing thc DC bins voltagc of tlic swildi. An atlvanlage or mil' design is t1i:it thc bcam morlc can be chosen electronically, not mecliani- cally.
h s i x n u j I. WA mid S P D T circuit: As s h o w schem;itically in Fig. I, the unit consists of an SPDT control circcuit, a imtchiug
circuit and ;t microsiiip two-termiuill feeding leaky-wave sritenria. Thc KT/Duriod subsirate uscd has a thickness oTO.508 m m atid a diclmtric conu~mt of E, = 2.2. 'llw SPST switches, forming an
SlW[' switch, were designed by using a cotnmerckally wiikiblc CAD tool HP-Ebof Lihra. Wc iiscd an MIA COM MA4GW30
Gahs pin diodc as thc solid-statc dcvicc in an SPDT switch tu
obhin low insertion loss, high isolation leval, Cis1 swilchirig speed, and high power capflcity.
leaky-wave antenna (L)
port 1
n
matching,A
{,/ circuitpin diode A Fig. 2 SPDT cuanrrol cirruif
f
pin diode To excite the first higher order mode within the operating fke- quency range, thc niicrostrip Ic;iky-ivave antenna is fcd asynimctri- calIy, and thc width 1.V and bnylli L of lhc anrciina arcempii~ically chosen 10
be
1.06cm ~ t i d 12cin, respectively. A rigor- ous (Wiener-Hopt) soliit ion IS] is cmployerl to find the tior~n;ilised coinplcx propagxtiun cuiistrtnl l3k0 -jor/ko of thc firs1 highchcr ordcr niodc, wlicrc P!kn is tlic nornialiscd p l w c mnstanl and u/ko is thc normalised atienuation constsilt. The varinlions in!MO
atid wko with frequency are plotted in Fig. 3. The nortiimlised phisc can-stiiiit p/kn is lcss than I, and iiiost of thc ridkiting ciicrgy lcaks in
the form of the space wave.
7
0.60.2
v
.,
Theuw(ird und cx3wimoifd re,w/i,s: The S I W ' eIemeni lias three ports and works in four nperating modes, the left-lia~id brim
modc, the right-liand h e m mode, tlic dual-benin mode and the
beam-off mode. Wlcn diodc A is ON (foiward-biascd) and diode B is OFF (no bias), no signal psscs through port 2 and all
UT
tlicinput power will appear at porl 3. This is rererred to AS the oiie-
beam inode. Wlieti diodc A is ON niicl diodc tl is ON, tlic input sigunl wiil llc rcliirncd at port I (tlcnm-off mode). Wlicii diodc A
and diodc U art: bod1 OFI:, thc SITT works as
a
power dividcl and the inpul power is split in half (tlunl-t)cani mode).90
180 0
180
Pig. 5 Mcmrrred i l w l - h i w r ~ .sc(iiitiirifi r d i i i t i u r i pi1ricrri.T j u r pwpi).vcri
onrenrrir rrt 9,2, r),Y cind i(l.bGIrz
-a-
9.R GT.12-
A
W G W. - I0.6CrHz
Fig. 4 shows the mcssuretl oire-he:iin scanning radiation pal- tcriis for this antcnna 31 9.3, L1.8 and I0.4GHz. The 11i;iiii bmins swiiig up from thc cnd-fice direction (tlic %-wxis), which is duirac- teristic of mi J ,WA, For the onc-bcsriii inode, the riicasurzd angles nfthc mititi beam ni-c 4 1 , 50 wiirl 41". Fig. 5 skows ihe mcasurcd dual-be;im scaiiniiig radiation piattei-ns at 9.2, 9.8 wild I0.6C;Hz. Notc that the measurcd sc;iiining aiiglcs for thc rig1it-h;ind beam
art: 65, 49 and 38"; meanwliile, tlic iiicasured angles fur the left- hand beam are I IS, 131 and 142", rcspcclivcly.
Cclnclusiuu: Wc 1i;ivc sumsshilly eniploycrl a two-tcrininal fcciliiig topology to CrciItc a dual-beam wdinlion pwltern and :in Sl'l>T
switch to elcctrouicallp select i i o n e - b c m or d d - b r a m radiation p:ittcni. This desigticd :intcniia Iias R largc bandwidth a i d flcxible
bcain-swirchitig mccIi;inism, aiitl will he a suitable candidate for
iiiohile and satcllitc cornmimicatiom spplications. The drcnit can bc casily iiiiplen~cntctl in i i innnoliihic array moddc.
Itcrcrcnccs
I MFN%III., w.: 'A iicw lravcling W ~ I Y C nntcnnn'. Proc. 8th I!uropclln
Microwavc Con[., 1978, pp. 3132. 30G
2 IOU. G.J., arid 'I'XIIANG, c.K,: 'Oscillator-typc ;ictivc-iiitcgratcd unleni~n: 7 ' 1 1 ~ lcaky-made ;ipproi~ch', IEllli' 7iioic., 1996, MTI'-44, pp. 2265-2272
3 I . I I X E Y . c., and IAIIIIX 11;. J.-W 'Simplc ilcsigii or rluol-hc;im Icaky- Wavc ;intciiiias in rnicroslrips', {fils 1'10~. Microw. A i I t i w 1 ~ i s
R . c i p i ~ ~ r r / . , 1997, 144, (6) pp 307-402
4 WANG, C.L. I O U C.K, and U'W, J.J.: 'A novcl two-bcnin sc:inning latkj'-wavc itntenixi', N E E %.inrz, 1999, A1'47, (S), pp, 1314 1317
CIIANG, IX, arid KIIESTER. IKI;,! 'Total and Iinrtial rcflcction lioiii Chc cnd of a parallel-pltuc wnvoguidc with an extended diclcctric dah', Koiiiu S c i , 1981, Ih, pp. I -13
5
Broadband microstrip
patch
antennas
for
MM ICs
W.S.T. Rowe and
R.D.
WatcrliouseA t)rondb:ind microosirip ~ R I C I I ;iincnii:i woll suitcd for niuliolitliic Inicrowaw inlegnrletl cjrciiitn (MMICs) is prescnled. 'IW :intcnnH cxliihiir a tncosurcd b:uidwidili 01' 35'%, IOW surfam WIVC loss, i i
high f"-io-back nith, i dic tihl,icatcrl dircctly OII lhe MMlC suhslrutc 1mIcrinl. Thc prcilic.tcd aivl maistwed input itnpcdanccs RII? givsn along willi Ihc iiicasurctl radiation Iwfaniimiicc.
h i 6 r u d ~ ~ t i o ~ : Atitemis suhblc for integrtition with monolithic inicrowwc iiitcgratcti circiiits (MM ICs) anri optoclecb"ic intc- gratcd circuits (0F.ICs) linw found nuiiicroils appliciitioiis, SIICII
its fibre-based antenna rcnioling, phased arrays, and quasi-optical
power combining systcms [I]. ?'he integration of the antcnna with microwave and/or oplical componcnts gcncratcs i~ coinpact, low-
profile, liglitwcight tiittl low-cost arcchilcc(iirc.
To bc integiated, the mtcnnit miat he rahrimtecl on the Iiigli diclcclric co~stdiit tnatcriiil uscd Tor the MMICs. This make? thc
imteona siisccpliblc l o wrrace wnvc cxcitaliun. A iew sttctripls
lime bccn made lo tlaign an antciin;i to m c d thc rcquirerncnts fuc inicgration [2, 31. Howevcr, most cworts reveal a iiarrow impxi-
iiiicc hintlwidtti (< WO), iindlilr R reduced gain a n t c n n ~ t due to s w
l-iice wave loss.
Rcccnlly, two MMK-coinpaiible priiibxl niiteniIa structures
h v c lwei1 reported with low ~ ~ i r h x wnvc loss atid a widc hnnd-
width: thc hi-lo slackctl patch [4]; and tlic coplaiiar waveguide (CPW) fcd ;ipcrlurc shcked patch (ASP) [5]. The CPW fed ASP,
liowcvcr, suffers finin ii rclativzly IOW front-to-hick ratio of - 1 1 dR, which conipliMcs the packaging of' I h c inlcgmled M M I U ~iiteiiiia. Tlic hi-lo stacked patch h;is ii much higher lront-to-hack rwtio of -22d0 on i i sirnilat. sizcd groiind plmc as (he CPW fcd
ASP, yct h;is n smaller iiiipxlmcc biindwidlli (-25% coinparctl to
I n h i s Letter, the hi-lo skicketl piitch configunition is extendcd 10 enliancc thc hindwidth. An cxtIa pxisitic pakh is iidded to h e lii-lu slriictwe nil a slab of low dielectric foain. Thc m c a s a r d results for this new hi-10-10 gcoiiiclry will he prescntcd, aiitl thc 40%).
