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Project Title: Development of Microstrip Flexible Active Antenna for

Terrestrial Digital TV Reception
Name of the Investigator: Mr. Teerapong Pratumsiri,

Abstract

The development of a flexible printed active antenna for the digital television (DTV)

reception in areas having poor signal or in high-rise buildings. The antenna structure is

composed of a meander line printed on a polyimide film as a radiating element. It has a
thickness of 0.3 mm, highly flexible, and very lightweight. The design and analysis of the

radiating element are based on a full-wave method implemented by a commercial

electromagnetic simulation software. The amplifier circuit consisting of a surface-mount
transistor and passive components are integrated directly on the polyimide film, residing

next to the feed line, to improve the antenna performance and minimize the whole
antenna dimension. The impedance matching between the radiating element, the feed

line, and the active circuit are considered.

The active antenna prototype test and measured by 4 steps, laboratory test, field test,
drive test and indoor reception test. The measured results show that the return loss of

more than approximately 10 dB, the maximum gain of about 18 dB, and the Omni-
directional radiation pattern are achieved in the operating frequency band of 510-790

MHz. The active antenna was installed in a vehicle for a drive field test in several areas of

Bangkok and its suburbs with assessed along around the country in the North, East, West,
and South directions, each with the speed 60-80 km./hr. good reception quality and

reliability was achieved all the way along the test routes in many provinces. The results

due to its flexibility, low profile, lightweight, and additional gain, the proposed flexible
active antenna could be useful for various specific applications.

Keywords: Micro strip antenna, Flexible printed active antenna, Digital television antenna.