摘要:
A wireless security device includes a nonconductive housing, a mother circuit board, a wireless expansion card, and a metal reflector. The mother circuit board and the wireless expansion card are disposed in the nonconductive housing. The mother circuit board includes a processor. The wireless expansion card includes a dielectric substrate, a ground plane, an inverted-F antenna, and an RF (radio frequency) module. The metal reflector is positioned between the mother circuit board and the wireless expansion card, and is close to the inverted-F antenna. The metal reflector is configured to reduce EMI (Electromagnetic Interference) from the mother circuit board so as to maintain performance of the inverted-F antenna.
摘要:
A device for enhancing electromagnetic susceptibility comprises a first bridge. The first bridge is near to a first trace of a differential pair routing and electrically connects an RF grounding with an analog grounding. The RF grounding and the analog grounding are separated. The differential pair routing transmits signals between an RF circuit and an analog circuit. The first trace of the differential pair routing is closer to an antenna coupled to the RF grounding than a second trace of the differential pair routing. The RF circuit is coupled to the RF grounding, and the analog circuit is coupled to the analog grounding.
摘要:
A phase shifter includes a substrate, an input part, a plurality of first transmission lines, a plurality of second transmission lines, a coupling part, a controller, and a plurality of output parts. When a signal is fed in a first transmission line, the fed signal is distributed to a corresponding second transmission line via the first transmission line, and an area of the second transmission line shielded by the coupling part is changed by rotating the coupling part through the controller, so as to shift a phase of the signal transmitted by the second transmission line.
摘要:
A phase shifter including a substrate, a plurality of first transmission lines, a plurality of second transmission lines, and a coupling portion is described. After the phase shifter feeds a signal into the first transmission lines, the first transmission lines assign the signal to the second transmission lines. Moreover, the coupling portion moves to change an area of the second transmission lines shielded by the coupling portion, so as to change the phase of the signal transferred by each of the second transmission lines.