Abstract: A multiband filter circuitry utilized in a radio-frequency (RF) system is disclosed. The multiband filter circuitry operates at a plurality of operating frequency bands. The multiband filter circuitry comprises at least a switchable-filtering series. Each of the at least a switchable-filtering series comprises a first terminal coupled between the antenna and the RF processing unit; a second terminal coupled to a ground; and a plurality of switchable-filtering units connected in series, each comprising a filtering unit; and a switching unit, connected to the filtering unit in parallel.

Abstract: An electronic device includes a circuit board. The circuit board includes a power amplifier footprint configured for mounting a first power amplifier or a second power amplifier thereon. The power amplifier footprint includes a first part and a second part. The first part includes multiple I/O pads. When the first power amplifier is mounted on the circuit board, the I/O pads in the first part are coupled to the first power amplifier. The second part includes multiple I/O pads. When the second power amplifier is mounted on the circuit board, both the I/O pads in the first part and the I/O pads in the second part are coupled to the second power amplifier.

Abstract: A radio frequency (RF) module capable of self-calibration is provided. According to an embodiment, the RF module includes an RF signal processor, a plurality of RF signal paths, an antenna switch module (ASM), and a power detector. The RF signal paths are connected between the RF signal processor and the ASM. The ASM has an antenna port and selectively connects the RF signal processor to the antenna port through one of the RF signal paths. The power detector is operative to detect power of an RF transmission signal that exits the antenna port of the ASM and enters an antenna when the ASM connects an RF transmission path of the RF signal paths to the antenna port of the ASM.

Abstract: A radio frequency (RF) module capable of self-calibration is provided. According to an embodiment, the RF module includes an RF signal processor, a plurality of RF signal paths, an antenna switch module (ASM), and a power detector. The RF signal paths are connected between the RF signal processor and the ASM. The ASM has an antenna port and selectively connects the RF signal processor to the antenna port through one of the RF signal paths. The power detector is operative to detect power of an RF transmission signal that exits the antenna port of the ASM and enters an antenna when the ASM connects an RF transmission path of the RF signal paths to the antenna port of the ASM.

Abstract: An electronic device includes a circuit board. The circuit board includes a power amplifier footprint configured for mounting a first power amplifier or a second power amplifier thereon. The power amplifier footprint includes a first part and a second part. The first part includes multiple I/O pads. When the first power amplifier is mounted on the circuit board, the I/O pads in the first part are coupled to the first power amplifier. The second part includes multiple I/O pads. When the second power amplifier is mounted on the circuit board, both the I/O pads in the first part and the I/O pads in the second part are coupled to the second power amplifier.

Abstract: A connection device for connecting a bag to a bicycle saddle a first connection unit connected between the saddle frame and the top of the bag, and a second connection unit which is connected between the seat post and the rear end of the bag. The second connection unit uses a clip member to clip on the seat post. The first connection unit includes a first portion connected to the saddle frame and a second portion pivotably connected between the first portion and the bag which can be pivoted upward when the second connection unit is disengaged from the seat post, and the angular position for the bag can be set as needed.

Abstract: A flyback converter is comprised of a primary side and a secondary side. The primary side includes a primary winding and a switch both connected in series. The secondary side includes a secondary winding, a tertiary winding, a first resistor, a capacitor, a second resistor, and an MOSFET (metal-oxide-semiconductor field-effect transistor). The first resistor, the capacitor, and the second resistor are connected in series and together connected in parallel with the tertiary winding. The MOSFET is connected in parallel with the first resistor at its gate and source. Accordingly, when the switch is turned on/off, the power energy provided at the primary side can be transferred to the secondary side in a flyback manner.

Abstract: A flyback converter is comprised of a primary side and a secondary side. The primary side includes a primary winding and a switch both connected in series. The secondary side includes a secondary winding, a tertiary winding, a first resistor, a capacitor, a second resistor, and an MOSFET (metal-oxide-semiconductor field-effect transistor). The first resistor, the capacitor, and the second resistor are connected in series and together connected in parallel with the tertiary winding. The MOSFET is connected in parallel with the first resistor at its gate and source. Accordingly, when the switch is turned on/off, the power energy provided at the primary side can be transferred to the secondary side in a flyback manner.

Abstract: A hand brake includes a mounting frame mounted on a handlebar grip of a wheeled walker and defining a working space with an open side and a closed end wall. A cable pull block is disposed inside the working space, and has an upper part pivoted to the mounting frame by a first pivot, and a lower part serving as a force bearing part and connected to a transmission cable under tension. A control lever has a pivot part extending into the working space via the open side thereof, and an operating part extending outwardly of the working space. The pivot part has an upper portion that is provided with an upwardly opening accommodating space. The accommodating space has a base wall. The cable pull block extends downwardly into the accommodating space such that the lower part confronts the base wall. The lower part of the control lever is pivoted to the cable pull block by a second pivot parallel to and disposed below the first pivot.