Transactions on Antennas and Propagation

X (c) 2016 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission. See http://www.ieee.org/publications_standards/publications/rights/index.html for more information.
This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication. Citation information DOI TAP, IEEE
Transactions on Antennas and Propagation
> REPLACE THIS LINE WITH YOUR PAPER IDENTIFICATION NUMBER (DOUBLE-CLICK HERETO EDIT) <
11
and corresponds to a jg of 0.25, which makes the distribution of
M
(Fig. c) unstable. ab) (c) Fig. 19 Interval of
H
,
V
and
M
of inhomogeneous radome corresponding to Table III (a) 40° scan angle. (b) 80° scan angle. (c) 6° scan angle with
=0.2. From all of the aforementioned information about overlap ratio, range ratio and the corresponding IPD distribution, the statement in Section II (B) can be validated small negative overlap ratio and large positive range ratio, corresponding to small jg, make
M
resemble
(cf. Fig. 10, 12, 14, 15, 16 and Table III, III, whereas large overlap ratio and large range ratio, corresponding to large jg, make
M
resemble
H
or
V
(cf. Fig. 9, 11, 12, 13, 15, 18 and Table III, III. Otherwise, as shown in Fig. 17 and Table III, small positive overlap ratio and small range ratio yield unstable
M
distribution, which can probably be different with
,
H
or
V
. Table IV summarizes the aforementioned results about inhomogeneous ra- dome. It can be seen that, as discussed in Section II (B, with the increase of jg, the distribution of
M
varies gradually from being similar with polarization angle to being similar with incident angle (or
H
/
V
). At 6° scan angle, IPD distribution similar with incident angle can bring about smaller BSE than polarization angle while at 16° scan angle contrary result arises. At larger scan angle, such as 40° or 80°, as the interval length of
M
is very small, the effect of IPD distribution on BSE can be ignored. Therefore, the boresight error (BSE) characteristics of the inhomogeneous radome can be estimated from
H
and
V
, which determine jg and
M
. Comparing
=0.99 and
=0.2 at 6° scan angle, different IPD similarity (pola./inci.) leads to different BSE (large/small). TABLE IVS UMMARY OF THE RESULTS ABOUT INHOMOGENEOUS RADOME INTERVAL UNIT
:
RAD
)
0.99 0.2 Scan angle
6°
16°
40°
80°
6°
jg
-0.03
(<0.1)
-0.2
(<0.1)
-0.14
(<0.1)
0.25
(>0.1,
<0.5)
1.63
(>0.5)
IPD similar with pola. (√) or inci. (×) or unstable (○)? Interval length of
M
(rad)
0.236 0.145 0.053 0.029 0.187
BSE small Furthermore, Fig. 20 plots the interval characteristics of
H
and
V
of inhomogeneous radome, CTR and VTR during antenna scanning. Fig. a) and (b) plot the overlap ratio and range ratio and Fig. c) plots the jg computed from overlap ratio and range ratio by (7). It can be seen that
=0.2 inho- mogeneous radome, constant thickness radome (CTR) and variable thickness radome (VTR) all have relatively large overlap ratio and range ratio and, thus, large jg, which ensure that they can yield IPD distribution similar to

Download 1 Mb.

Share with your friends: