Current density, azimuth radiation pattern, upon reception

1
MOBILE RECEPTION ANTENNA FOR DIGITAL TELEVISION
SUPERVISOR ASSOC. PROF. MAREK E. BIALKOWSKI
DONE BY HOW YUE WONG
Introduction In view of digital television
ability to provide better picture resolution,
multimedia capabilities (advertisement),
bandwidth reduction, better signal to noise or
interference ratio, many countries have interest
to develop mobile antennas for reception of
digital television programs. In this thesis,
computer aided design packages, includes FEKO
and NECEAM, have been used to simulate the
design before constructing the antenna for mobile
television.

• Product
• Specifications
• Horizontal polarization
• Omnidirectional
• Low profile (small in size)
• Low cost
• Frequency range from 526Mhz to 582Mhz
• Frequency span of 56Mhz

COMPUTER SIMULATION ON TURNSTILE ANTENNA
COMPUTER SIMULATION ON CROSS-BOWTIE ANTENNA

Cross-Bowtie Geometry
Turnstile Geometry
Triangle sheet length 90mm, 1.5mm Thickness, 30o
Flare angle, Feed gap 7mm, quarter wavelength
height from ground plane
Half wavelength dipole 120mm in length, 3mm
thickness Polyethylene dielectric supporting
structure 2mm thickness, loss tangent 0.0005,
permittivity 2.3
Feed gap
Simulation of Turnstile on Automobile Rooftop
3D Radiation Plot
HALF-WAVELENGTH DIPOLE
Current density, azimuth radiation pattern, upon
reception
Longer length resonate at lower frequency
Turnstile Antenna with Radome Design
Thicker wire lower input impedance
Closer feed gap better current distribution
400Mhz
630Mhz
Azimuth Radiation Pattern for Turnstile antenna
RESULTS TURNSTILE CROSS-BOWTIE
554Mhz
( 515-585)Mhz
Matching with 50 ? characteristic impedance
630Mhz
400Mhz
-24dB _at_ 550Mhz
Balun
Turnstile Physical Realization
Matching with 50 ? characteristic impedance
(515-570) Mhz
-15dB _at_ 535 Mhz
45j4?
Match with 75? characteristic impedance
(505-585)Mhz
Center frequency554Mhz
73j8? _at_554Mhz
-32.2dB_at_ 545Mhz