Manipulation of circular polarised electromagnetic waves by artificial periodic structures (Invited Paper)

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1 Manipulation of circular polarised electromagnetic waves b artificial periodic structures (Invited Paper) Zelenchuk, D., & Fusco, V. (215). Manipulation of circular polarised electromagnetic waves b artificial periodic structures (Invited Paper). Paper presented at The Eeter Microwave Metamaterials Meeting, Eeter, United Kingdom. Document Version: Other version Queen's Universit Belfast - Research Portal: Link to publication record in Queen's Universit Belfast Research Portal Publisher rights 215 The Authors. General rights Copright for the publications made accessible via the Queen's Universit Belfast Research Portal is retained b the author(s) and / or other copright owners and it is a condition of accessing these publications that users recognise and abide b the legal requirements associated with these rights. Take down polic The Research Portal is Queen's institutional repositor that provides access to Queen's research output. Ever effort has been made to ensure that content in the Research Portal does not infringe an person's rights, or applicable UK laws. If ou discover content in the Research Portal that ou believe breaches copright or violates an law, please contact openaccess@qub.ac.uk. Download date:7. Jun. 218

2 Manipulation of circular polarised electromagnetic waves b artificial periodic structures Overview D. Zelenchuk, and September V. Fusco 24 December 8, 215

3 Circularl polarised wave RHCP wave E = E φ φ = ± π 2 LHCP wave The hand is defined from the point of view of the source

4 Outline Spectral selectivit: CP frequenc selective surfaces Beam forming: Conical beam generation with rotational phase shift Polarisation selectivit: circularl polarised selective surface (CPSS)

5 Motivation o o o o Frequenc selective surfaces (FSS) remain a ke component of satellite antenna feeding sub-sstems The provide low-loss filtering and beam-splitting capacit that allows using single antenna for multiband operation FSS is dual-polarisation or even circular polarisation (CP) properties Properties of the dielectric stack utilised to support printed FSS structure becomes crucial for successful design

6 Frequencies (GHz) Losses (db) Specification Rejection (db) Aial Ratio (db) Ku-band Ka-band Reflected <.25dB 3 db N/A degree angle of incidence! Transmitted <.25dB

7 CP FSS Γ i = 1 + Γ c TE = Γ c TM 1 2Z c Z

8 Ku-band Reflection Ka-band Transmission Air-filled design

9 Material stack inside the structure Manufactured material stack

10 Full-wave simulation of the FSS with different stack

-6-7 1 15 2 25 Frequenc (GHz) There is a notable

11 Reference -1 Measured results: -2-3 Substrate onl Magnitude(dB) -4-5 Rvv sim Rhh sim Rvv meas Rhh meas Frequenc (GHz) There is a notable difference between the measured results and simulation of the material stack

12 Measured results ε r = tan δ =

13 2face 2face Magnitude(dB) Aial ratio(db) -1-2 Measured results:fss -4-3 Tvv sim Thh sim Tvv meas Thh meas Frequenc (GHz) face Meas T Meas R Sim T Sim R Frequenc (GHz) Magnitude(dB) Rvv sim Rhh sim Rvv meas Rhh meas Frequenc (GHz)

14 Conical beam applications Conical beam antennas have omnidirectional radiation pattern in azimuth and a notch in the normal direction Eotic applications : Data transfer b free-space modes with non-zero orbital angular momentum Vorte coronograph, where object is in the shadow of much brighter one

15 Conical beam generation spiral phase plate helicoidal dish sectorial spiral reflector

16 Spiral phase plate 1 s l s for 2 l, l 1 Generation of helical beam: (a) amplitude of incident Gaussian beam, (b) spiral phase plate, (c) amplitude of resultant Laguerre-Gaussian beam.

17 Rotational phase shift ' ' q r h t i r r r r r r r r R E E q q q q q q q q cos sin sin cos cos sin sin cos ' ' ' ' z k j i e j E z k j r j R e j e ' q E CP ecitation Half-wave plate condition Unit cell of the reflecting FSS

18 LP analsis of reflecting FSS a 1 ' R 3 a R 2 2 R 1 R 4 d R 1,mm R 2,mm R 3,mm R 4,mm a 1, deg a 2, deg h, mm d, mm ' (db) () Frequenc (GHz) Frequenc (GHz)

19 CP analsis of reflecting FSS (db) ' ' q r Out In -4 rcp lcp lcp lcp rcp lcp lcp Frequenc (GHz) E (db) () R ' e j 2qr 1 1 e j q r () j k z rcplcp rcprcp lcplcp lcprcp

20 11 arra factor Arra factor of a finite arra with given phase distribution. AF q, m n A mn e j( k m sin q cosk n sin q sin ( m, n)) (, ) 1 tan,, 1 tan, 1 tan 2,, Predicted arra factor of the 11 arra with spiral phase distribution (a) amplitude, (b) phase.

11 arra EM simulation,, 2 tan, tan,, tan ), ( 1 1 1 ), ( n m Simulated 3D

21 11 arra EM simulation,, 2 tan, tan,, tan ), ( ), ( n m Simulated 3D bi-static RCS of the 11 slit ring reflectarra with spiral phase distribution.

Manufactured sample,, 2 tan, tan,, tan ), ( 1 1 1 The reflector has been milled from a 1mm thick

22 Manufactured sample,, 2 tan, tan,, tan ), ( The reflector has been milled from a 1mm thick aluminum with solid aluminum ground plane. The 7.5mm separation is maintained with plastic screws.

23 Measurement setup The setup consists of illuminating dualpolarized horn and rotating fiture with reflector and receiving Fermi antenna Rotating fiture with reflector and receiving Fermi antenna

Receiving fiture Radiation pattern (db) -1-2 -3-4 E-plane H-plane 1 GHz -15-1 -5 5 1 15 q () Fermi antenna and its

24 Receiving fiture Radiation pattern (db) E-plane H-plane 1 GHz q () Fermi antenna and its radiation pattern in E- and H-plane Rotating fiture with the reflector and Fermi antenna Fermi antenna foam fiture

25 Radiation pattern (db) -2 Measured results Freq: 1.4 LP measurement result Pol: Plane:z measured measured simulated simulated q () q () Comparison of simulated and measured radiation patterns (normalised) when ecited b a normall incident -polarized plane wave at 1.4 GHz. (a) E q for = and -9<q<9 (b) E q for =9 and -9<q<9 Pol: Plane:z

26 CP measurement results Radiation pattern (db) -1 (b) -2 measured simlated q () Comparison of simulated and measured radiation patterns (normalised) in plane = when ecited b a normall incident CP-polarized plane wave at 1.4 GHz.

27 Transmit-arra ' α 1 R 3 R 1 α 2 θ r ' t h Unit cell R 2 t R 4 (a) (b) Measurement setup

28 Measured radiation pattern Magnitude Phase (a) RHCP, (b) LHCP ecitation

29 Polarisation selectivit (CPSS) (a) (b) Reciprocal smmetrical right-hand circular polarisation selective surface: (a) reflection, (b) transmission.

30 Jones matri formulation General case: LP and CP Jones matrices f = S 21 S21 T lin = S S A B C D f T circ = 1 2 A + D j(b C A D j(b + C A D + j(b + C A + D + j(b C RHCPSS: LP and CP Jones matrices f T circ = 21 S A = D = jb, B = C LCP,LCP

31 Single SRR model Co-polar Cross-polar

32 SRRs magnetic coupling Twisted SRR Unit cell Coupling inductance L m = k h L 3

33 Equivalent circuit of 9 degree TSSR C2 p L2 n L3-Lm n C3 p 2 2*Lm n 1 C3 p L3-Lm n C1 p 2 2*Lm n L2 n C2 p 4 C1 p 2

34 Fitted vs CST

35 RHCPSS RO 43C h3=.5mm Rohacell foam h2=5mm RO 43C, h1=.5mm

36 Measurement RHCPSS

14. Matrix treatment of polarization

14. Matrix treatment of polarization 14. Matri treatment of polarization This lecture Polarized Light : linear, circular, elliptical Jones Vectors for Polarized Light Jones Matrices for Polarizers, Phase Retarders, Rotators (Linear) Polarization