In this paper we provide a system design method to solve the problem of developing a miniaturized portable digital TV set. For such a portable device it is very important to reduce power consumption and extend operation time while the battery is the only power source in the system. The hardware circuitry shall be relatively compact according to the high integration of the system-on-chip (SOC) and the proper selection of key components. Not only miniaturization can be realized but also cost and power dissipation of the system decreased. Whether the implementation can be achieved also depends on antenna efficiency and DVB-T receiver performance. Therefore it is vital to select the right radio frequency architecture, which affects signal reception and power consumption. Based on the demands mentioned above we have chosen single conversion architecture for the receiver. Furthermore, our design has a better performance than earlier designs because of the use of a shielding case and the appropriate filtering of power ripples. Our efforts aim at making the antenna wideband, small-sized, low-profile, low-cost and omnidirectional. We implement the built-in antenna body by means of the printed circuit board at low cost. Meanwhile the spiral antenna is a good choice to fulfil the requirements of a wideband omnidirectional radiation pattern. Moreover, a heat sink conducts the heat outward and thus prevents overheating, ensuring operational safety.
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