SLIDE 1
1
2
- !"!#$#!% &'
!(")*++,++-. (&/0(12! 2 (0345$2 !#%) (16'7(2!6-.
GEO satellite terminal 1 train GEO satellite
8(1
- --811-.
Aperture blockage in mechanically scanned multi-beam lens antenna - - PowerPoint PPT Presentation
Aperture blockage in mechanically scanned multi-beam lens antenna - - PowerPoint PPT Presentation
Aperture blockage in mechanically scanned multi-beam lens antenna for satellite communications in Ku band. John Thornton Department of Electronics, University of York, YO10 5DD. United Kingdom. jt21@ohm.york.ac.uk 1
SLIDE 2
SLIDE 3
3
- 2%/9:;)
)( 6-
εr 1 εr 2 r1 r2 f Bibliography:
- J. Thornton, "Scanning Ka-band Vehicular Lens Antennas for Satellite and High Altitude
Platform Communications" 11th European Wireless Conference, Nicosia, Cyprus, 10-13 April
2005
- J. Thornton, “Wide-scanning Multi-layer Hemisphere Lens Antenna for Ka band.” IEE
Proceedings Microwaves, Antennas & Propagation, Volume 153, Issue 6, December 2006. pp. 573-
578.
- J. Thornton, T.C.Tozer, “Lens antennas for multi-satellite and multi-frequency band
communications on trains.” IET Seminar: "Broadband on Trains", London, 20 February 2007.
SLIDE 4
4
- lens
elevation motor
circumfrential azimuth rail
azimuth carriage azimuth motor primary feed on elevation trolley
coax or optic fibre centre bearing direction of beam pedestal ground plane this region not blocked
5''(()1( 1''(- 5''''-
(has to be terminated here)
SLIDE 5
5
- lens
circumfrential azimuth rail...aperture blockage
azimuth carriage
coax or optic fibre (reel) direction of beam ground plane
5'(1''(- 5'61'(-
- --1(((-
(extends as far as space allows)
SLIDE 6
6
- feed
virtual lens
- rail
rail
SLIDE 7
7
- 13.00°
62.00°
C
C
L
R 305.0 mm R 340.3 mm
required elevation angles derived from range of latitudes plus train maximum roll angle
SLIDE 8
8
!
cable trunking motor 84:1 gearbox 141 mm position sensor L gearbox
azimuth rail
e l e v a t i
- n
r a i l
SLIDE 9
9
!
457.5mm radius (1.5 x 305mm)
cable termination area
cable trunking motor 84:1 gearbox 141 mm L gearbox e l e v a t i
- n
r a i l
azimuth rail
rack and pinion magnetic sensor IF coaxial cables
SLIDE 10
10
"#$$%
&'$
SLIDE 11
11
(( )
<='('1'(- <='1- :('1'(=> ?(@(6'6'('$%6A.
- ---1('
- (
. + ''. B+-,-C (D
.
,+
* from lens centre
SLIDE 12
12
*
copper wall lens feed
SLIDE 13
13
+
,))+E
- 5
5 10 15 20 degrees
- 40
- 35
- 30
- 25
- 20
- 15
- 10
- 5
dB
without rail
loss due to rail ~ 0.3 dB
with rail
7' 7 7' 7 +-, +- +-C
- 9
SLIDE 14
14
,-
E /(+. =,+F.)/
- 30
- 20
- 10
10 20 30
angle (°)
- 50
- 40
- 30
- 20
- 10
dB
ground plane 1 ground plane 2
~ 0.8 dB ~ 0.8 dB ~ 0.8 dB ~ 0.8 dB
SLIDE 15
15
- E -
240 mm 240 mm 240 mm 240 mm
SLIDE 16
16
457.5mm radius (1.5 x 305mm)
cable termination area
cable trunking motor 84:1 gearbox L gearbox e l e v a t i
- n
r a i l
azimuth rail
rack and pinion magnetic sensor IF coaxial cables
SLIDE 17
17
- this space reserved
for magnetic strip (to be fitted)
SLIDE 18
18
+
(1=) )16('''/
(
- magnetic sensor
pinion
prototype rail (coax) alternative rails (fibre)
36 mm (14 mm scaled) 25 mm, or less... 13 mm minimum ? (scales to 5 mm) 9 1.5 ?
SLIDE 19
19
,
!"##
- 60
- 40
- 20
20 40 60
- 50
- 40
- 30
- 20
- 10
dB
- 30
- 20
- 10
10 20 30
- 50
- 40
- 30
- 20
dB
,9E
no rail with rail
+E
H-plane, 28 GHz H-plane, 28 GHz
+
SLIDE 20
20
'$-#.°
- 30
- 20
- 10
10 20 30 degrees
- 40
- 30
- 20
- 10
dB
without rail with rail
H-plane 31 GHz 24°elevation degrees
- 30
- 20
- 10
10 20 30
- 40
- 30
- 20
- 10
dB E-plane 28 GHz 24°elevation
SLIDE 21
21
*
* was we’ve made for first mechanical prototype with coax cables
- ''
.
- ''
. 7' 7 7' 7 7' 7
, D +-, +- +-C
- 9
- 9
- +
- +
+ +-B +-C
- +-C
9
- +
+ +- +-, +- +-B
24° elevation 18° elevation 30° elevation
loss due to rail (dB) all measurements at 28 GHz
SLIDE 22
22
/
(+),E
28 29 30 31 f (GHz) 0.2 0.4 0.6 0.8 1
dB
E-field horizontal E-field vertical
SLIDE 23
23
('( =1)6-
)((-
G'', (-
2*-9:.E H,E @('-
(16(''-
I1(''J (4#:'
- (.''6+-:J +-,:-
0'('16(-
SLIDE 24
24
- 5''7(2!6(