Abstract: An expandable wireless transceiver is provided. The expandable wireless transceiver includes an antenna, a receiver, a transmitter and a switch connector. The antenna detects an electromagnetic signal in surrounding space and receives a signal with a first central frequency according to the detection result. The receiver receives the signal based on the detection result of the antenna. The transmitter outputs a radio-frequency signal. A third connection terminal of the switch connector provides a connective path to an expansion antenna. According to the coupling condition of the third connection terminal, the switch connector delivers the radio-frequency signal to its second connection terminal or third connection terminal. Thus, the radio-frequency signal with a second central frequency is transmitted to surrounding space through the antenna or the expansion antenna, wherein the second central frequency and the first central frequency are both in a specific band.

Abstract: An active UHF amplifier includes a transistor having a base for receiving signals, a grounded emitter, and a collector for outputting signals, a first inductor having a first end for coupling to a voltage source, the inductance of the first inductor being between 10-100 nano-Henries, a first capacitor having a first end coupled to the first end of the first inductor, a second inductor having a second end coupled to the base of the transistor, the inductance of the second inductor being between 1-100 nano-Henries, a second capacitor having a first end coupled to a first end of the second inductor, the capacitances of the first and the second capacitor being between 10 pico-Farads and 100 nano-Farads, a first resistor, and a second resistor having a resistance divided by the resistance of the first resistor and multiplied by a voltage of the voltage source being between 0.5-0.8 volts.

Abstract: A wireless transmission device capable of transmitting media from different channels concurrently. The transmitter of the device places the inputted TV signals and an audio/video signal on different segments of a frequency spectrum, combines the signals of all segments into one combined signal, and transmits the combined signal as a radio frequency signal so as to transmit signals from different channels at the same time. Meanwhile, a controller in the receiver of the device selects a needed channel signal from the received radio frequency signal according to a selection signal. Therefore with one A/V transmitter and multiple A/V receivers, multiple-channel media transmission and multiple-channel media reception is achieved.

Abstract: The present invention is directed to a power converter, which includes a first switching voltage regulator, some linear voltage regulators, and a second switching voltage regulator. The first switching voltage regulator is electrically connected between input ports and an output terminal. One ends of the linear voltage regulators are respectively electrically connected to the input ports. The second switching voltage regulator is respectively electrically connected between another ends of the linear voltage regulators and the output terminal.

Abstract: A wireless communication system includes an antenna, a receiving module, a power source, and a power control hub. The power control hub includes an amplifier having a first end coupled to the receiving module and a second end coupled to the power source. The amplifier generates a first output signal based on a control signal of the receiving module. The power control hub includes a rectifier having a first end coupled to the output end of the amplifier and a second end coupled to the power source. The rectifier generates a second output signal based on the first output signal. The power control hub also includes a switch. A first and a second end of the switch are electrically connected or disconnected based on the second output signal received at a control end of the switch.

Abstract: An active UHF amplifier includes a transistor having a base for receiving signals, a grounded emitter, and a collector for outputting signals, a first inductor having a first end for coupling to a voltage source, the inductance of the first inductor being between 10-100 nano-Henries, a first capacitor having a first end coupled to the first end of the first inductor, a second inductor having a second end coupled to the base of the transistor, the inductance of the second inductor being between 1-100 nano-Henries, a second capacitor having a first end coupled to a first end of the second inductor, the capacitances of the first and the second capacitor being between 10 pico-Farads and 100 nano-Farads, a first resistor, and a second resistor having a resistance divided by the resistance of the first resistor and multiplied by a voltage of the voltage source being between 0.5-0.8 volts.

Abstract: A wireless transmission device capable of transmitting media from different channels concurrently. The transmitter of the device places the inputted TV signals and an audio/video signal on different segments of a frequency spectrum, combines the signals of all segments into one combined signal, and transmits the combined signal as a radio frequency signal so as to transmit signals from different channels at the same time. Meanwhile, a controller in the receiver of the device selects a needed channel signal from the received radio frequency signal according to a selection signal. Therefore with one A/V transmitter and multiple A/V receivers, multiple-channel media transmission and multiple-channel media reception is achieved.