Abstract: A power supply unit supplies power to a load, and the power supply unit includes a power factor corrector, a DC conversion module, and an isolated conversion module. The power factor corrector is plugged into a first main circuit board and converts an AC power into a DC power. The DC conversion module is plugged into the first main circuit board and converts the DC power into a main power. The isolated conversion module includes a bus capacitor, the bus capacitor is coupled to the DC conversion module through a first power copper bar, and coupled to the power factor corrector through a second power copper bar. The first power copper bar and the second power copper bar are arranged on a side opposite to the first main circuit board, and are arranged in parallel with the first main circuit board.

Abstract: A touch position coordinate detecting system is provided that is based on surface acoustic waves and includes arrays of reflective patterns between a touch region of a touch panel. An initial burst that includes two frequency components is sent on the panel. The reflective arrays include two sub-arrays centered respectively at the two frequencies. A touch on the panel involves an absorption of the acoustic waves traveling in the region of the panel, and provides a localized damping in a time output signal. A time localized damping is detected for each reflected frequency components, thereby enhancing the signal-to-noise ratio of the system.

Abstract: The present invention discloses a dual-band power amplifier, capable of operating at a first frequency and a different second frequency simultaneously. The dual-band power amplifier comprises a first gain stage; a second power stage; an input matching unit electrically connected between the first gain stage and a signal input port; an inter-stage matching unit electrically connected between the first gain stage and the second power stage and an output matching unit electrically connected between the second power stage and an output signal port. According to the dual-band power amplifier and the design formula of matching circuit of the present invention, the present invention can simplify the circuit structure and is suitable for various dual-band communication systems.

Abstract: A touch position coordinate detecting system is provided that is based on surface acoustic waves and includes arrays of reflective patterns between a touch region of a touch panel. An initial burst that includes two frequency components is sent on the panel. The reflective arrays include two sub-arrays centered respectively at the two frequencies. A touch on the panel involves an absorption of the acoustic waves traveling in the region of the panel, and provides a localized damping in a time output signal. A time localized damping is detected for each reflected frequency components, thereby enhancing the signal-to-noise ratio of the system.