Abstract: The present invention is to provide a PCB based band-pass filter for cutting out harmonic of high frequency wherein in manufacturing a circuit board of a wireless communication product technology of PCB production is utilized to mount an input microstrip line, an output microstrip line, an open circuit microstrip line, and a short circuit microstrip line of the band-pass filter on the circuit board. By utilizing the present invention, it is possible of utilizing an unoccupied area of the circuit board to mount a band-pass filter thereon without using an additional filter of high frequency. Moreover, the band-pass filter is adapted to cut out harmonic of two, three, or four times of a fundamental frequency caused by nonlinear distortion of a power amplifier of the wireless communication product.

Abstract: The present invention discloses a dual-frequency antenna, wherein a coplanar wave guide wire is printed onto a dielectric substrate, so that an end of the coplanar wave guide wire can be used as a signal input end, and a ground metal surface is printed onto the same side of the dielectric substrate at a position corresponding to the periphery of the coplanar wave guide wire. The ground metal surface keeps a certain distance from the coplanar wave guide wire, and the other end of the coplanar wave guide wire is extended outside the ground metal surface. A radiating member is extended from a side along the direction of the longitudinal axis, and a meandered conductive wire is extended from the other side at the end of the longitudinal axis. The radiating member is parallel to the conductive wire, and a gap is kept in parallel to the edge of the ground metal surface, so that each radiating member can be used to receive signals of different frequencies.

Abstract: The present invention is to provide a method of optimizing packet flow and fully utilizing available bandwidth in a packet transfer path of duplex ring stackable switch, which comprises implementing in a ring network including a plurality of switches; setting a plurality of interruption points each at a location farthest from a unique one of the switches; dividing a packet output path of each switch into two different transfer paths; selecting either transfer path based on an initialization when one of the switches is about to send a packet to the other switch; and sending the packet from one switch to the other switch along the selected transfer path.

Abstract: The present invention discloses a dual-frequency antenna, wherein a coplanar wave guide wire is printed onto a dielectric substrate, so that an end of the coplanar wave guide wire can be used as a signal input end, and a ground metal surface is printed onto the same side of the dielectric substrate at a position corresponding to the periphery of the coplanar wave guide wire. The ground metal surface keeps a certain distance from the coplanar wave guide wire, and the other end of the coplanar wave guide wire is extended outside the ground metal surface. A radiating member is extended from a side along the direction of the longitudinal axis, and a meandered conductive wire is extended from the other side at the end of the longitudinal axis. The radiating member is parallel to the conductive wire, and a gap is kept in parallel to the edge of the ground metal surface, so that each radiating member can be used to receive signals of different frequencies.

Abstract: The present invention is to provide a microwave filter distributed on a circuit board of a wireless communication product, which comprises an input terminal, a resonant chamber of double frequencies, and an output terminal of the microwave filter directly distributed on the circuit board of the wireless communication product as a plurality of microstrips by utilizing a manufacturing technique of printed circuit board for eliminating the harmonic spurious of double frequencies and higher frequency caused by nonlinear distortion of a power amplifier of the wireless communication product.