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7/27/2019 A Novel Fss With Ultra-wideband Polarization Selective Response
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A Novel Frequency Selective Surface with
Ultra-Wideband Polarization Selective ResponseWan-lu Li, Guo-hui Yang, Tong Zhang, Qun Wu
School of Electronics and Information Technology
Harbin Institute of Technology
No. 92 Xidazhi Street
Harbin, Heilongjiang Province, China 150001
Abstract - A novel frequency selective surface (FSS) with
ultra-wideband (UWB) polarization selective response is proposed,
in which a unit cell consists of two metallic plane of a novel
asymmetry pattern. Simulation results prove that the FSS can
realize selectivity of waves of a certain polarization with the
bandwidth more than 36.5%, and for different incident angles the
bandwidth can be broader. Moreover, effects of parameters of the
structure on transmission performances of the FSS are researched
and conclusions are presented, which provides theoretical basis
for practical application.
I. INTRODUCTION
Frequency selective surfaces (FSS) are planar periodic arrays
of metal patches or slots that function as filtering elements for
free-space radiation [1] – [4]. Their shape and dimensions as
well as the substrate characteristics determine the performance
of an FSS structure and they are selected and optimized
according to different specifications. FSSs are widely used as polarizers, space filters, subreflectors in dual frequency
antennas and as radomes for radar cross section (RCS)
controlling [5]. One of the significant applications, polarizers,
is by making use of a special characteristic of
FSS — polarization selectivity. Based on this property
polarization-selective filtering element can be made up and
used in many fields, such as so-called filtennas combining an
antenna with a filtering shield in a single unit [6], and it can be
employed in quasi-optical systems requiring a separation of
polarization, such as it is the case e.g., in polarimetric imaging
radars and/or radiometers [7].
In this paper, a novel band-reject FSS with UWB
polarization selective response is proposed. Simulation by
CST Microwave Studio presents that for normal incident
waves the bandwidth of polarization selectivity band is
about 36.5%, while for oblique incident waves the
bandwidth is wider. In addition, the bandwidth and starting
frequencies of the polarization selectivity band can be
adjusted by changing parameters of the structure, which proves
the practicability of the proposed FSS.
II. FSS STRCTURE AND ITS PERFORMANCES
To realize a linear polarization selective surface, thestructure is designed as Fig.1 shows. Unlike conventional FSS
pattern, such as cross-line structure or rectangle structure, this
pattern is designed to be asymmetry to realize the polarization
selectivity. As Fig.1 shows, two metallic layers of the novel
asymmetry pattern are placed on top and bottom side of the
dielectric substrate. The pattern mainly consists of three
semi-circles with a co-edged point. On the side of the radius,
the semi-circles are cut by a triangle, of which the vertex is
also the edge point of the semi-circles. Therefore, the
connected part forms a large inductance, while the gap part
forms a capacitance. Moreover, compared with single-circle
structure, this multi-circle structure improves bandwidth of the
FSS. Structure of the periodic array of the FSS is shown in
Fig.2.
To testify the polarization-selective performance of the
proposed FSS, simulation is conducted with all the parameters
are defined as follows: thickness of the dielectric substrate
h=2mm, relative dielectric constant of the substrate εr =2.2,
thickness of the metal strips t =0.2mm, outer radius of thesemi-circles r =3mm, radius difference of the semi-circles
y=d =0.3mm, apex angle of the cutting triangle α=45⁰, and
distance between adjacent two semi-circles g =0.3mm.
Transmission performances of the FSS when illuminated by
normal incident waves are shown in Fig.3.
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a ) T o p v i e w
b ) S i d e v i e w
F i g . 1 S t r u c t u r e o f t h e p r o p o s e d F S S
F i g . 2 S t r u c t u r e o f t h e p e r i o d i c a r r a y
F i g . 3 T r a n s m i s s i o n p e r f o r m a n c e s o f t h e F S S w h e n i l l u m i n a t e d b y n o r m a l
i n c i d e n t w a v e s
F r o m F i g . 3 i t c a n b e o b s e r v e d t h a t f o r T E - p o l a r i z e d w a v e s
t h e r e a r e t w o r e s o n a n t f r e q u e n c i e s b e t w e e n f r e q u e n c y b a n d s
0 - 1 5 G H z , a n d f o r t h e r e j e c t p e r f o r m a n c e b a n d o f w h i c h t h e
i m p e d a n c e i s m o r e t h a n 2 0 d B t h e b a n d i s f r o m 8 . 2 2 G H z t o
1 1 . 8 9 G H z , w i t h 3 . 6 7 G H z b a n d w i d t h . S i n c e i m p e d a n c e o f t h i s
b a n d f o r T M - p o l a r i z e d w a v e s i s n o m o r e t h a n 3 d B , t h i s
f r e q u e n c y b a n d p r e s e n t s g r e a t p o l a r i z a t i o n s e l e c t i v i t y
c h a r a c t e r i s t i c . T h e r e f o r e , s i n c e t h e c e n t e r f r e q u e n c y o f t h e
p o l a r i z a t i o n s e l e c t i v i t y b a n d i s 1 0 . 0 5 5 G H z , i t c a n b e c o n c l u d e d
t h a t t h e b a n d w i d t h o f t h e F S S f o r n o r m a l i n c i d e n t w a v e s i s
a b o u t 3 6 . 5 0 % .
S i n c e c h a r a c t e r i s t i c s o f a g r e a t F S S s h o u l d b e s t a b l e w i t h
r e s p e c t t o w a v e s o f d i f f e r e n t i n c i d e n t a n g l e s , s i m u l a t i o n f o r
w a v e s o f 3 0 ⁰ a n d 6 0 ⁰ i n c i d e n t a n g l e i s c o n d u c t e d a n d r e s u l t s
a r e p r e s e n t e d i n F i g . 4 . I t c a n b e o b s e r v e d t h a t w i t h t h e i n c r e a s e
o f i n c i d e n t a n g l e , s t a r t i n g f r e q u e n c y o f t h e p o l a r i z a t i o n s e l e c t i v i t y b a n d d e c r e a s e s , w h i l e e n d i n g f r e q u e n c y o f t h e b a n d
i n c r e a s e s . A s a r e s u l t , b a n d w i d t h o f t h e p o l a r i z a t i o n s e l e c t i v i t y
b a n d i n c r e a s e s . W h i l e f o r n o r m a l i n c i d e n t w a v e s t h e b a n d w i d t h
i s 3 6 . 5 0 % , f o r o b l i q u e i n c i d e n t w a v e s i t r i s e s u p t o 3 8 . 1 4 % a n d
4 5 . 9 6 % . T h u s , t h e F S S p r e s e n t s e x c e l l e n t p o l a r i z a t i o n
s e l e c t i v i t y c h a r a c t e r i s t i c f o r w a v e s o f d i f f e r e n t i n c i d e n t a n g l e s .
F i g . 4 T r a n s m i s s i o n p e r f o r m a n c e s o f t h e F S S w h e n i l l u m i n a t e d
b y w a v e s o f d i f f e r e n t i n c i d e n t a n g l e s
I I I . P A R A M E T E R S ’ E F F E C T S
A . O u t e r r a d i u s
S i n c e o u t e r r a d i u s d e t e r m i n e s t h e d i m e n s i o n o f t h e u n i t c e l l
o f t h e F S S , i t h a s a l a r g e e f f e c t o n i t s r e s o n a n t f r e q u e n c y a n d
b a n d w i d t h . T h e r e f o r e , w h i l e a l l t h e o t h e r p a r a m e t e r s a r e k e p t t o
b e t h e s a m e , t r a n s m i s s i o n p e r f o r m a n c e s o f t h e F S S w i t h
d i f f e r e n t o u t e r r a d i u s a r e s i m u l a t e d , a n d r e s u l t s a r e s h o w n i n
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F i g . 5 . I t c a n b e o b s e r v e d t h a t t h e i n c r e a s e o f o u t e r r a d i u s
r e s u l t s i n m i n i a t u r i z a t i o n o f b o t h o f t h e r e s o n a n t f r e q u e n c i e s ,
a n d t h e r e f o r e b o t h t h e s t a r t i n g f r e q u e n c y a n d e n d i n g f r e q u e n c y
o f t h e p o l a r i z a t i o n s e l e c t i v i t y b a n d a r e m i n i a t u r i z e d . I t c a n b e
o b s e r v e d t h a t w h i l e t h e o u t e r r a d i u s o f t h e F S S i n c r e a s e f r o m
2 . 5 m m t o 3 . 0 m m a n d 3 . 5 m m , s t a r t i n g f r e q u e n c y o f t h e
p o l a r i z a t i o n s e l e c t i v i t y b a n d c h a n g e s f r o m 1 0 . 0 7 G H z t o
8 . 2 2 G H z a n d 6 . 8 8 G H z , a n d e n d i n g f r e q u e n c y c h a n g e s f r o m
1 4 . 5 2 G H z t o 1 1 . 8 9 G H z a n d 9 . 9 5 G H z . H o w e v e r , t h e
b a n d w i d t h s f o r e a c h s i t u a t i o n a r e 3 6 . 1 9 % , 3 6 . 5 0 % a n d 3 6 . 4 8 % ,
w i t h r e a l l y l i m i t e d v a r i e t y . T h u s b y a d j u s t i n g t h e o u t e r r a d i u s
o f t h e F S S t h e s t a r t i n g a n d e n d i n g f r e q u e n c i e s o f t h e
p o l a r i z a t i o n s e l e c t i v i t y b a n d c a n b e m o d u l a t e d , w h i l e
b a n d w i d t h s t a y s t h e s a m e .
F i g . 5 T r a n s m i s s i o n p e r f o r m a n c e s o f t h e F S S s w i t h d i f f e r e n t o u t e r r a d i u s e s
w h e n i l l u m i n a t e d b y n o r m a l i n c i d e n t w a v e s
B . R a d i u s d i f f e r e n c e
T o i n v e s t i g a t e e f f e c t s o f r a d i u s d i f f e r e n c e o f t h e F S S ,
t r a n s m i s s i o n p e r f o r m a n c e s o f t h e F S S s w i t h d i f f e r e n t r a d i u s
d i f f e r e n c e s w h i l e k e e p i n g t h e o u t e r r a d i u s t h e s a m e i s
s i m u l a t e d a n d t h e r e s u l t s a r e p r e s e n t e d i n F i g . 6 . I t c a n b e
o b s e r v e d t h a t w i t h t h e i n c r e a s e o f r a d i u s d i f f e r e n c e , b o t h t h e
s t a r t i n g a n d t h e e n d i n g f r e q u e n c y o f t h e p o l a r i z a t i o n s e l e c t i v i t y
b a n d i n c r e a s e . S i m i l a r w i t h e f f e c t s o f o u t e r r a d i u s , b a n d w i d t h
o f t h e F S S d o e s n o t c h a n g e w i t h v a r i a t i o n o f r a d i u s d i f f e r e n c e .
F o r t h e F S S w i t h r a d i u s d i f f e r e n c e 0 . 3 m m , 0 . 4 m m a n d 0 . 5 m m ,
t h e b a n d w i d t h i s a b o u t 3 6 . 5 0 % , 3 6 . 4 7 % a n d 3 6 . 6 5 % . T h e r e f o r e
c h a n g i n g t h e r a d i u s d i f f e r e n c e c a n a l s o b e u s e d t o a d j u s t t h e
v a l u e s o f s t a r t i n g a n d e n d i n g f r e q u e n c i e s o f t h e F S S w h i l e
k e e p i n g t h e b a n d w i d t h t h e s a m e .
F i g . 6 T r a n s m i s s i o n p e r f o r m a n c e s o f t h e F S S s w i t h d i f f e r e n t r a d i u s d i f f e r e n c e s
w h e n i l l u m i n a t e d b y n o r m a l i n c i d e n t w a v e s
C . C u t t i n g a n g l e
S i n c e t h e a n g l e o f t h e c u t t i n g t r i a n g l e d i r e c t l y d e t e r m i n e s t h e
c u t t i n g l e n g t h o f e a c h s e m i - c i r c l e , a n d t h e r e f o r e d e t e r m i n e s
e q u i v a l e n t i n d u c t a n c e a n d c a p a c i t a n c e o f e a c h p a r t ,
t r a n s m i s s i o n p e r f o r m a n c e s o f t h e F S S w i t h d i f f e r e n t c u t t i n g
a n g l e i s r e s e a r c h e d , a n d r e s u l t s a r e s h o w n i n F i g . 7 . I t c a n b e
o b s e r v e d t h a t w i t h t h e i n c r e a s e o f c u t t i n g a n g l e , b o t h t h e
s t a r t i n g a n d e n d i n g f r e q u e n c i e s o f t h e p o l a r i z a t i o n s e l e c t i v i t y
b a n d a r e i n c r e a s e d . B u t u n l i k e t h e o t h e r t w o p a r a m e t e r s ’ e f f e c t s ,
c u t t i n g a n g l e s a l s o h a s e f f e c t s o n b a n d w i d t h o f t h e p o l a r i z a t i o n
s e l e c t i v i t y b a n d . W i t h t h e c u t t i n g a n g l e i n c r e a s e s f r o m 3 0 ⁰ t o
4 5 ⁰
a n d 6 0 ⁰
, t h e b a n d w i d t h i n c r e a s e s f r o m 3 1 . 3 4 % t o 3 6 . 5 0 % a n d 4 0 . 5 6 % . T h u s , b y i n c r e a s i n g t h e c u t t i n g a n g l e t h e
b a n d w i d t h o f t h e p o l a r i z a t i o n s e l e c t i v i t y b a n d c a n b e f u r t h e r
b r o a d e n e d .
F i g . 7 T r a n s m i s s i o n p e r f o r m a n c e s o f t h e F S S s w i t h d i f f e r e n t c u t t i n g a n g l e s
w h e n i l l u m i n a t e d b y n o r m a l i n c i d e n t w a v e s
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I V . C O N C L U S I O N
I n t h i s p a p e r , a n o v e l b a n d - r e j e c t F S S w i t h U W B
p o l a r i z a t i o n s e l e c t i v i t y r e s p o n s e i s p r o p o s e d . B y t h e u t i l i z a t i o n
o f t h e n o v e l p a t t e r n m o d i f i e d f r o m f r a c t a l s e m i - c i r c l e s t h e F S S
c a n r e a l i z e a w i d e p o l a r i z a t i o n s e l e c t i v i t y b a n d w i t h t h e
b a n d w i d t h m o r e t h a n 3 6 . 5 % f o r n o r m a l i n c i d e n t w a v e s , a n d f o r o b l i q u e t h e b a n d w i d t h i s b r o a d e r . I n a d d i t i o n , b o t h t h e s t a r t i n g
a n d e n d i n g f r e q u e n c i e s a n d b a n d w i d t h o f t h e F S S c a n b e
a d j u s t e d b y m o d u l a t i n g t h e t h r e e p a r a m e t e r s o f t h e s t r u c t u r e :
o u t e r r a d i u s , r a d i u s d i f f e r e n c e a n d c u t t i n g a n g l e . T h u s t h e
p r o p o s e d F S S h a s a p r o m i s i n g f u t u r e i n p r a c t i c a l a p p l i c a t i o n
f o r a n t e n n a a n d r a d a r s y s t e m s .
A C K N O W L E D G M E N T
T h e a u t h o r s w o u l d l i k e t o e x p r e s s t h e i r s i n c e r e g r a t i t u d e t o
C S T L t d . G e r m a n y , f o r p r o v i d i n g t h e C S T T r a i n i n g C e n t e r
( N o r t h e a s t C h i n a R e g i o n ) a t o u r u n i v e r s i t y w i t h a f r e e p a c k a g e
o f C S T M W S s o f t w a r e .
T h i s w o r k w a s s u p p o r t e d b y t h e N a t i o n a l N a t u r a l S c i e n c e
F o u n d a t i o n o f C h i n a u n d e r G r a n t 6 0 8 0 1 0 1 5 a n d 6 1 0 0 1 0 3 6 .
R E F E R E N C E S
[ 1 ] T . K . W u , F r e q u e n c y S e l e c t i v e S u r f a c e a n d G r i d A r r a y . N e w Y o r k : W i l e y ,
1 9 9 5 .
[ 2 ] J . C . V a r d a x o g l o u , F r e q u e n c y S e l e c t i v e S u r f a c e s . N e w Y o r k : W i l e y ,
1 9 9 7 .
[ 3 ] B . A . M u n k , F r e q u e n c y S e l e c t i v e S u r f a c e s : T h e o r y a n d D e s i g n . N e w
Y o r k : W i l e y I n t e r s c i e n c e , 2 0 0 0 .
[ 4 ] R . M i t t r a , C . H . C h a n , a n d T . C w i k , “ T e c h n i q u e s f o r a n a l y z i n g
f r e q u e n c y s e l e c t i v e s u r f a c e s — A r e v i e w , ” P r o c . I E E E , v o l . 7 6 , D e c . 1 9 8 8 ,
p p . 1 5 9 3 – 1 6 1 5
[ 5 ] G u o Q i n g L u o , W e i H o n g , Z h a n g - C h e n g H a o , B i n g L i u , W e i D o n g L i , J i
X i n C h e n , H o u X i n g Z h o u , a n d K e W u , T h e o r y a n d E x p e r i m e n t o f N o v e l
F r e q u e n c y S e l e c t i v e S u r f a c e B a s e d o n S u b s t r a t e I n t e g r a t e d W a v e g u i d e
T e c h n o l o g y , I E E E T r a n s a c t i o n s O n A n t e n n a s a n d P r o p a g a t i o n , v o l . 5 3 ,
n o . 1 2 , D E C E M B E R 2 0 0 5 , p p . 4 0 3 5 - 4 0 4 3
[ 6 ] J . E . R o y a n d L . S h a f a i , “ R e c i p r o c a l c i r c u l a r - p o l a r i z a t i o n - s e l e c t i v e
s u r f a c e , ” I E E E A n t e n n a s P r o p a g a t i o n , v o l . 3 8 , n o . 6 , D e c . 1 9 9 6 , p p .
1 8 – 3 3
[ 7 ] W i n k l e r , S . A . , H . W e i , e t a l . “ P o l a r i z a t i o n R o t a t i n g F r e q u e n c y S e l e c t i v e
S u r f a c e B a s e d o n S u b s t r a t e I n t e g r a t e d W a v e g u i d e T e c h n o l o g y . ”
A n t e n n a s a n d P r o p a g a t i o n , I E E E T r a n s a c t i o n s o n 5 8 ( 4 ) : 1 2 0 2 - 1 2 1 3 .