Metamaterial-Based. Sungjoon Lim, Christophe Caloz and Tatsuo Itoh University of California, Los Angeles OUTLINE

Transcription

1 Metamaterial-Based Electroically-Cotrolled Leaky-Wave Atea Sugjoo Lim, Christophe Caloz ad Tatsuo Itoh Uiversity of Califoria, Los Ageles OUTLINE Left-Haded Metamaterial (LHM) Approaches Composite Right/Left-Haded (CRLH) Trasmissio Lie (TL) Leaky-Wave Atea Applicatio Priciple of Electroically-Cotrolled CRLH TL Electroically-Scaed Leaky-Wave Atea Applicatio Radiatio Agle Cotrollig & Beamwidth Tuig Capability Noliear effects of Varactors Coclusios

2 / Differet Approaches of LHMs Historical Milestoes oretical aalysis of hypotical LH materials by Veselago itroductio of electric (ε<) / magetic (µ<) plasmo by Pedry experimetal demostratio of LH structure by Smith ε < ad µ < v v < LH defiitio materials with p g ad uit-cell << λ effective / macroscopic / homogeeous Resoat Structure Approach UCSD, D-LH Trasmissio Lie Approach ( j C ) = ω BACKWARD WAVES approach o simple/rigorous aalysis & o desig method approach Trasmissio lie aalysis structures RESONANT very lossy & circuit desig methods & arrow badwidth structures NON-RESONANT low loss & highly dispersive & broad badwidth BACKWARD WAVES S. Ramo, J.R. Whiery ad T. Va Duzer, & moderate dispersio Fields ad waves i commuicatio electroics, Wiley, 4 ( j L ) Y = ω high-pass A iterdigit al capacitor CRLH TL ad Domiat Mode LW Atea Applicatio β = cos ( '( ω) Y'( ω)) / d A LR C L C L LR B '( ω) = jωlr jωcl B shorted (via) stub LL CR Y Y '( ω) = jωcr jωl L ω = βc I LH GUIDANCE II LH RAD. ω III RH RAD. ω ω = βc IV RH GUIDANCE β Domiat mode operatio ( = ) β π / d β θ = si = si k k Efficiet broadside ω Backward (II. LH ) ad forward (III. RH) radiatio

3 Motivatio of Voltage Scaed LW Atea Covetioal LWA Frequecy depedet scaig Covetioal Electrically-Scaed LWA Frequecy idepedet scaig Oly two discrete states are possible Waveguide cofiguratio with PIN diode Covetioal Magetically-Scaed LWA Frequecy idepedet scaig Biasig DC magetic field NOT practical Waveguide cofiguratio Novel Electroically Scaed LWA Frequecy idepedet scaig Efficiet Chaelizatio Cotiuous scaig capability Microstrip techology Low profile R. E. Hor, et. al, Electroic modulated beam steerable silico waveguide array atea, IEEE Tra. Microwave Theory Tech. H. Maheri, et. al, Experimetal studies of magetically scaable leaky-wave ateas havig a corrugated ferrite slab/dielectric layer structure, IEEE Tras. AP. L. Huag, et. al, A electroically switchable leaky wave atea, IEEE Tras. AP. Priciple of Voltage Scaed Leaky Wave Atea ω V 3 V V ω = cβ ( β = k ) β θ ( V ) = si k ω β = β > β < RH LH β k β ( V ) θ ( V ) = si k V V V 3 Scaig Scaig agle agle is is depedet o o iductaces ad ad capacitaces Itroducig varactor varactordiodes Capacitive Capacitive parameters are are cotrolled cotrolled by by voltages voltages Dispersio Dispersio curves curves are are shifted shifted vertically vertically as as bias bias voltages voltages are are varied varied Radiatig Radiatig agle aglebecomes a fuctio fuctio of of varactor varactor diode s diode s voltages voltages 3

4 Beamwidth Cotrol Capability Priciple Beamwidth Beamwidth U U U 3 U 4 U U U U U 3 U 4 U U V V V V V V V V V3 V 4 V V Uiform biasig No-uiform biasig Uiformly Uiformly biased biasedperiodic TL TL Each Each uit uit cell cell radiates radiates toward toward same sameagle agle High High directivity directivity No-Uiformly biased biasedperiodic TL TL Each Each uit uit cell cell radiates radiates toward toward differet differetagles Beamwidth is is determied by by superpositio of of each each cell cell Broader Broader beamwidth Uit Cell Implemetatio A iterdigit al capacitor B GND A LR C L C L LR B varactor A B B shorted (via) stub LL CR Y LR,var C L, var C L, var L R, var L C C L R, L, L, R, Reverse Reversebiasig to to Varactors Varactors Aodes Aodes of of varactors varactors GND GND Cathodes Cathodes of of varactors varactors Biasig Biasig The The cathodes cathodes of of three three varactors varactorsi i same same directio directio Oly Oly oe oebias circuitry circuitry i i uit uit cell cell Series Seriesad ad Shut ShutVaractors Fairly Fairly costat costat characteristic characteristic impedace impedace Additioal Additioal degree degree of of freedom freedom for for wider wider scaig scaig rage rage Back Back to to back back cofiguratio cofiguratioof of two two series series varactors varactors Fudametal Fudametal sigals sigals i i phase phase ad ad add add up up Harmoic Harmoic sigals sigals out out of of phase phase ad ad cacel cacel A GND iductor L L, C R,var Y C L R, L, L DC V DC Bias Cofiguratio 4

5 Aalysis with Parameter Extractio LR,var CL, var CL, var L R, var LR, C C L, L, L R, ABCD Trasmissio Matrix A B '( V) Y '( V) '( V){ '( V) Y '( V)} C D = '( V) Y '( V) Uit _ Cell Bloch-Floquet Theorem L L, C R,var C L R, L, L DC V DC jβ d V e V = jβ d I e I Y β ( V ) = cos ( '( V ) Y '( V )) / d '( V) = jωl R,var jωc L,var jω LR,C L, LR,varC L = CL, CL j L V ω ( ),var,var ( V) ω L R, C ( V) ω ( L L R, jωc L C R,var L, R, L, R,var L,var ) d ( V) ω Y V '( ) = jωl d L, = ω LL, jωc R,var ( V ) jωc R, jω jωc R, / C ( V) jωl R,var jωl L, L, d d Aalysis with Parameter Extractio Parameters Extracted Circuit Model 3.33 GHz ad d =. cm Voltage L R,var [H] C R,var (=C L,var ) [pf] L L [H] C R [pf] L L [H] C L [pf] L R [H] V V V...4. Frequecy [GHz] Dispersio Diagram V V V β / k β ( V ) = cos ( '( V ) Y '( V )) / d Scaig agle [degree] 4 Expected Scaig Agle Theory θ ( V ) = si β ( V k ) Reverse bias voltage [V]

6 Scaig agle [degree] MoM Full-Wave Simulatio Feed Feed Feed Feed Backward Backward Propagatig Capability higher higher applied applied voltage voltage ( ( V) V) Feed Feed Feed Feed Forward ForwardPropagatig Capability lower lower applied appliedvoltage ( ( V) V) 3 Cell Leaky Wave Atea Implemetatio 3 3 V = V, LH ( β < ) V =. V, RH ( β > ) Shut varactor - Series varactors - Via µ strip d =. cm (. λ ) eff GND, Vb ( ) µ strip 3. cm (.4 λ ) Via eff Iductor (DC Feed) DC bias V ( b ) Port Port V = 3. V, Broadside ( β = ) Theory from parameter extractio Measuremet Reverse bias voltage [V] P i µ strip 3.34 cm (. λ ) Scaig Scaig Rage Rage θ θ = = º º (-4º (-4º to to º) º) Backward, Backward, forward, forward, ad ad broadside broadside Biasig Biasig Rage Rage V V = = V ( ( to to V) V) Fixed Fixed operatig operatig frequecy frequecy GHz GHz Maximum Maximum Gai Gai dbi dbi at at broadside broadside Atea Atea dimesio dimesio µ strip 3.34 cm (. λ ) eff eff L

7 Gai [dbi] Retur Loss at Port [db] Retur Loss at Port [db] Retur Loss at Port [db] Retur Loss at Port [db] Measured S Parameters versus Frequecy Port Excitatio Port -. V -. V V V 3. V V V Frequecy [GHz] V 3. V V V Frequecy [GHz] V Port Termiatio Port -. V -. V - V 3. V V V Frequecy [GHz] - V 3. V V V Frequecy [GHz] V V Performace as a LW Atea Scaig Agle [degree] HPBW [degree] Reverse bias voltage [V] High High directivity Oe Oe of of attractive characteristic of of LW LW atea Achieved by by icreasig umber of of cells cells Large Large radiatio aperture µ strip Atea dimesio 3.34 cm (. λ eff ) Maximum Gai Gai dbi dbiat at broadside (( V = V ))

8 Beamwidth Cotrol Capability Predictio Approximatio method Superpositio of each beam patter N ftotal ( θv ; ; θ ) ( ) ( ) V A w θv f θv = Beam patter at applied bias of V N αd = e w ( θ ) f ( θ ) = V V Expoetially decreasig as is icreasig N N umber umber of of elemets elemets d d distace distace of of uit uit cell cell f f (θ (θ V ) V ) ormalized ormalized beam beam patter patter fuctio fuctio A A atteuatio atteuatio w (θ (θ V ) V ) weightig weightig α α atteuatio atteuatio costat costat at at th th cell cell Sice Sice amplitude amplitude expoetially expoetially decreases decreases as as icreases, icreases, θ v, θ s v, s from from oset oset cells cells are are domiat domiat s. s. Isertio Loss Versus Reverse Voltage Voltage [V] Isertio loss per a sigle varactor [db] S & S [db] S S S Reverse bias voltage [V] S [db] Beamwidth Tuig Capability Measuremet (Normalized) Received Power [dbm (db)] Normalized, o-uiform, measuremet Normalized, o-uiform, ory Uiform V Uiform V UiformV LH Normalized, o-uiform, measuremet Normalized ouiform distributio from ory Uiform V Uiform V Uiform V RH - (Normalized) Received Power [dbm (db)] Agle [degree] Less power is radiated at ed of LW atea The first row becomes domiat Agle [degree] Uiform biasig No-Uiform biasig ( V to V, V to V) Uiform biasig No-Uiform biasig ( V to V, V to V) HPBW mi HPBW max HPBW HPBW mi HPBW max HPBW V V 4º (43 to % V V 3º (4 to % icreased)

9 Received power [dbm] Received Power [dbm] Output power per toe [dbm] 4 - Noliear Effects of Varactors Two Toe Test Fudametal (Measuremet) Output IM3 (Measuremet) Fudametal (Predictio) Output IM3 (Predictio) IIP3 IP3 OIP IMD = -3. dbc TX Frequecy [GHz] Iput power per toe [dbm] RX Two Two toe toe (3.3 (3.3 GHz GHz ad ad GHz) GHz) Test Test at at broad broad side side (( V = = V )) proposed proposed atea atea used used as as both both TX TX ad ad RX RX IIP3 IIP3 = =.3.3 dbm dbm as as TX TX atea atea Frequecy [GHz] Spectrum Aalyzer Frequecy Sysizer (3.3 GHz) Frequecy Sysizer (3.33 GHz) Power Combier d =. ich (3. cm) Noliear Effects of Varactors BPSK Data Trasmissio Basebad sigal (Mbps) Up Coversio BPF A TX RX B LNA BPF Dow Coversio LPF Demodulated sigal LO sychroizatio (3.33 GHz) Demodulated waveform for RX Demodulated wavefrom for TX Referece waveform Voltage [V] BPSK BPSK ( ( Mbps Mbps )) Data Data Trasmissio Trasmissio Test Test at at broad broad side side (( V = = V )) proposed proposed atea atea used used as as TX TX ad ad RX RX successfully successfully recovered recovered i i both both cases cases Noliear Noliear effects effects are are egligible egligible as as atea atea applicatios applicatiosi i far far field field regio regio Time [S]

10 Coclusios Novel Metamaterial-Based Electroically-Cotrolled TL Cotiuous Scaig Leaky-Wave Atea Radiatio Agle Cotrol at Uiform Biasig Beamwidth Cotrol at No-uiform Biasig Noliear Effects of Varactors Negligible