A folded monopole antenna fed by a CPW-to-trident transition feeder for compact wireless USB dongle devices is proposed. The antenna's dimensions are 1644.83.5 mm3, so it is suitable for low-profile wireless USB dongles. The proposed, compact monopole antenna resonates from 2.28 GHz to 10.8 GHz; hence, it can cover all wireless bands including WiBro (2.3–2.4 GHz), Bluetooth (2.4–2.484 GHz), WiMAX (2.5–2.7 GHz and 3.4–3.6 GHz), satellite DMB (2.605–2.655 GHz), 802.11b/g/a WLAN (2.4–2.485 GHz and 5.15–5.825 GHz), and UWB (3.1–10.6 GHz). A fabricated antenna is tested on a laptop to investigate the effects of the keypad and LCD screen on the resonant frequency and radiation pattern. The measured average gain of the fabricated antenna ranges from -2.76 dBi to 0.72 dBi.

The specific absorption rate (SAR) measurement procedure for wireless communication devices used in close proximity to the human body other than the ear was standardized by the International Electrotechnical Commission (IEC). This procedure is applicable to SAR measurement of data communication terminals that are used with host devices. Laptop PCs are assumed as host devices in this study. First, numerical modeling of laptop PCs and the validity of computations are verified with corresponding measurements. Next, mass averaged SARs are calculated dependent on the dimensions of the laptop PCs and the position of the terminals. The results show that the ratio of the maximum to minimum SARs is at most 2.0 for USB dongle and card-type terminals at 1950 MHz and 835 MHz.

To improve Digital Audio Broadcasting (DAB) receiver performance, we need to use better signal processing algorithm. However, it is impossible to modify the signal processing algorithm in DAB commercial hardware. In addition, the notebook PC based software radio research platform allows convenient acquisition of the massive radio data at variant environments and online analysis with variable signal processing procedure more easily. We have developed the first prototype portable software radio research platform for DAB which consists of a USB RF receiver module, USB interface and PC based software for device controlling and signal processing. Iterative decoding and ICI cancellation are also added to improve the performance in mobile channels.