Abstract: A multi-band antenna structure includes a substrate having a first wiring area located on one side surface thereof. The first wiring area has a first metal trace, a second metal trace and a connecting portion formed therein. The first and the second metal trace are respectively in an elongated spiral pattern; and the connecting portion is electrically connected at two opposite ends to the first and the second metal trace. The multi-band antenna structure can be directly integrated into electrical circuits on a circuit board to provide the advantages of reduced manufacturing cost and capable of transmitting or receiving multiple bands of signals.

Abstract: A multi-band antenna structure includes a substrate having a first wiring area located on one side surface thereof. The first wiring area has a first metal trace, a second metal trace and a connecting portion formed therein. The first and the second metal trace are respectively in an elongated spiral pattern; and the connecting portion is electrically connected at two opposite ends to the first and the second metal trace. The multi-band antenna structure can be directly integrated into electrical circuits on a circuit board to provide the advantages of reduced manufacturing cost and capable of transmitting or receiving multiple bands of signals.

Abstract: A specific multi-band antenna impedance matching circuit and a tire-pressure monitoring device using same are disclosed. The antenna impedance matching circuit includes at least one first, one second and one third inductance unit and at least one first, one second and one third capacitance unit. The first capacitance unit is connected at a first end to first ends of the first and the second inductance unit and at a second end to a ground; the second inductance unit and the second capacitance unit are connected in series; the third inductance unit and the third capacitance unit are connected in parallel; and the third inductance unit is connected at a first end to a first end of the second capacitance unit and at a second end to the ground.