Abstract: A radio-frequency signal receiver capable of enhancing reception performance includes an antenna for receiving radio-frequency signals, a first switch having an end coupled to the antenna, a filter coupled to the first switch, a second switch having an end coupled to the first switch and an end coupled to the filter, a low noise amplifier coupled to the second switch for amplifying signals received from the second switch, a frequency down converter coupled to the low noise amplifier for down-converting a frequency of signals outputted from the low noise amplifier, a signal processing circuit coupled to the frequency down converter for performing signal processing, and a control circuit for controlling the first and the second switches.

Abstract: A radio-frequency signal receiver capable of enhancing reception performance includes an antenna for receiving radio-frequency signals, a first switch having an end coupled to the antenna, a filter coupled to the first switch, a second switch having an end coupled to the first switch and an end coupled to the filter, a low noise amplifier coupled to the second switch for amplifying signals received from the second switch, a frequency down converter coupled to the low noise amplifier for down-converting a frequency of signals outputted from the low noise amplifier, a signal processing circuit coupled to the frequency down converter for performing signal processing, and a control circuit for controlling the first and the second switches.

Abstract: A water detecting system of a portable electric device comprises a housing, an electronic circuitry board, a battery electrically connected to the electronic circuitry board for providing electrical power to the electronic circuitry board, and at least one pair of electric terminals, the pair of electric terminals comprising one positive terminal and one negative terminal located in close proximity to the positive terminal. When the pair of electric terminals are electrically conducted, a current runs through the pair of electric terminals. The water detecting system also comprises a current detector electrically connected to the pair of electric terminals for detecting if the current running through the pair of electric terminals exceeds a threshold level, and a switch connected to the current detector and the battery for disconnecting the battery from the electronic circuitry board when the current exceeds the threshold level.

Abstract: A water detecting system of a portable electric device comprises a housing, an electronic circuitry board, a battery electrically connected to the electronic circuitry board for providing electrical power to the electronic circuitry board, and at least one pair of electric terminals, the pair of electric terminals comprising one positive terminal and one negative terminal located in close proximity to the positive terminal. When the pair of electric terminals are electrically conducted, a current runs through the pair of electric terminals. The water detecting system also comprises a current detector electrically connected to the pair of electric terminals for detecting if the current running through the pair of electric terminals exceeds a threshold level, and a switch connected to the current detector and the battery for disconnecting the battery from the electronic circuitry board when the current exceeds the threshold level.