1. Field of the Invention
The invention relates to overcome narrow bandwidth embedded antenna problem, and more particularly, to methods and antenna modules in combinative application of embedded antenna and systems which have the relatively large bandwidth, applied in Digital Video Broadcasting-Terrestrial (DVB-T) systems.
2. Description of the Related Art
As is known, it is planned that the transmission of broadcast radio and television signals will be changed completely from the analogue standard to the digital standard by 2010 at the latest. Transmissions will then be based on the Digital Video Broadcasting (DVB) Standard, which is suitable for digital reception of video and audio data via satellite, via cable or via terrestrially transmitted programs. The expressions DVB-S (for satellite reception), DVB-C (for cable reception) and DVB-T when the signals are transmitted terrestrially are used in a corresponding manner.
This DVB-T system transmits compressed digital audio, video and other data in an MPEG transport stream, using COFDM modulation. In the case of DVB-T, there are two choices for the number of carriers known as 2K-mode or 8K-mode. In addition, the bandwidth of DVB-T system is 430 MHz (from 470˜870 MHz). DVB-T system provides a wide operating bandwidth.
There is a general trend towards miniaturisation of portable electronic devices, including portable wireless devices. As a result, antennas compete for space with the other device components (e.g. battery, display, keypad, printed circuit board). An embedded antenna is used in the DVB-T product because the embedded antenna in size is relatively small. However, the embedded antenna bandwidth is quite narrow. For example, the embedded antenna bandwidth is above 120 MHz. The embedded antenna bandwidth is not enough wide such that the embedded antenna is not suited to use in the relatively large bandwidth system such like DVB-T system or other systems which have the relatively large bandwidth. The direct combination of embedded antenna and systems which have the relatively large bandwidth cause the system performance becomes worse.