Abstract: A transformer is provided with four capacitors and four inductors. The first capacitor is electrically connected between a first port and ground in series. The first inductor is electrically connected to the first port in series. The second capacitor is electrically connected between the first inductor and ground in series. The second inductor is electrically connected between the first inductor and the second capacitor in series. The third capacitor is electrically connected between a second port and ground in series. The third inductor is electrically connected to the second port in series. The fourth capacitor is electrically connected between a third port and ground in series. The fourth inductor is electrically connected between the third inductor and the third port in series.

Abstract: A balun device including a first to a third inductance elements and a first to a third capacitance elements is provided. The first inductance element has a first end for receiving an input signal and a second end. The second inductance element has a third end and a fourth end, wherein the third and the forth ends are for outputting a first and a second output signals corresponding to the input signal, respectively. The first output signal and the second output signal substantially have the same amplitude and opposite phases. The first and the second inductance elements generate mutual inductance. The first capacitance element is coupled to the first end. The second capacitance element is coupled to the third end. The third capacitance element is coupled to the fourth end. The third inductance element is seriesly connected to one of the first to the third capacitance elements.

Abstract: A dual inductance structure including a substrate, a first inductance element, a second inductance element and a grounding element is provided. The substrate has a layout layer and a grounding layer. The first inductance element has a first and a second conductor. The second inductance element has a third and a fourth conductor. The grounding element has a first and a second grounding portion. The first grounding portion is on the grounding layer and located at an area between the first conductor and the third conductor. At least a part of the second grounding portion is on the grounding layer and located at an area between the first conductor and the second conductor. At least another part of the second grounding portion is on the grounding layer and located at an area between the third conductor and the fourth conductor.

Abstract: A balun device including a first to a third inductance elements and a first to a third capacitance elements is provided. The first inductance element has a first end for receiving an input signal and a second end. The second inductance element has a third end and a fourth end, wherein the third and the forth ends are for outputting a first and a second output signals corresponding to the input signal, respectively. The first output signal and the second output signal substantially have the same amplitude and opposite phases. The first and the second inductance elements generate mutual inductance. The first capacitance element is coupled to the first end. The second capacitance element is coupled to the third end. The third capacitance element is coupled to the fourth end. The third inductance element is seriesly connected to one of the first to the third capacitance elements.

Abstract: A dual inductance structure including a substrate, a first inductance element, a second inductance element and a grounding element is provided. The substrate has a layout layer and a grounding layer. The first inductance element has a first and a second conductor. The second inductance element has a third and a fourth conductor. The grounding element has a first and a second grounding portion. The first grounding portion is on the grounding layer and located at an area between the first conductor and the third conductor. At least a part of the second grounding portion is on the grounding layer and located at an area between the first conductor and the second conductor. At least another part of the second grounding portion is on the grounding layer and located at an area between the third conductor and the fourth conductor.

Abstract: A transformer is provided with four capacitors and four inductors. The first capacitor is electrically connected between a first port and ground in series. The first inductor is electrically connected to the first port in series. The second capacitor is electrically connected between the first inductor and ground in series. The second inductor is electrically connected between the first inductor and the second capacitor in series. The third capacitor is electrically connected between a second port and ground in series. The third inductor is electrically connected to the second port in series. The fourth capacitor is electrically connected between a third port and ground in series. The fourth inductor is electrically connected between the third inductor and the third port in series.