A resonant rotating transformer design increases efficiency while maintaining the small dimensions of devices in which the transformer is used. The inventive concept lacks a ferrite or other metal core and instead uses at least two secondary winding members positioned near a primary winding member on a non-magnetic base. The lack of a ferrite core increases the overall lifespan and efficiency of the resonant rotating transformer while permitting the resonant rotating transformer's small dimensions of substantially under 100 mm, as well as resistance to stress and vibrational loads. The resonant rotating transformer is optimized for holographic fan displays but is useful for other electronic devices. Variations of sequential and parallel alignment for elements of the at least two secondary winding members, as well as various winding arrangements, enable changes of properties of the resonant rotating transformer.

A switch-type phase shifter including a phase shifting unit is provided. The phase shifting unit includes two half circuits and a first switch connected to the half circuits and receiving a first control signal. Each half circuit includes a first variable capacitor, a second variable capacitor, a second switch and a variable inductor. The two ends of the first variable capacitor are coupled to the input and the control nodes of the half circuit respectively. The two ends of the second variable capacitor are coupled to the output and control nodes of the half circuit respectively. The first and second ends of the second switch are coupled to the output and input nodes respectively, and the third end thereof is coupled to the control node and receives a second control signal. The two ends of the variable inductor are coupled to the input and output nodes respectively.

A switch-type phase shifter including a phase shifting unit is provided. The phase shifting unit includes two half circuits and a first switch connected to the half circuits and receiving a first control signal. Each half circuit includes a first variable capacitor, a second variable capacitor, a second switch and a variable inductor. The two ends of the first variable capacitor are coupled to the input and the control nodes of the half circuit respectively. The two ends of the second variable capacitor are coupled to the output and control nodes of the half circuit respectively. The first and second ends of the second switch are coupled to the output and input nodes respectively, and the third end thereof is coupled to the control node and receives a second control signal. The two ends of the variable inductor are coupled to the input and output nodes respectively.

An inductor circuit includes first inductive circuit, second inductive circuit, and third inductive circuit. First inductive circuit at receiver side has a first end coupled to a first port of an antenna and a second end coupled to an input port of a receiving circuit. Second inductive circuit at transmitter side has a first end and a second end respectively coupled to output ports of a power amplifier. Third inductive circuit at antenna side has a first end coupled to a first port of the antenna and having a second end. Second inductive circuit and the third inductive circuit are disposed on an outer ring to form a ring shape and the third inductive circuit is disposed on an inner ring within the outer ring to form a spiral shape. Third inductive circuit is disposed between the second inductive circuit and the first inductive circuit.

An inductor circuit includes first inductive circuit, second inductive circuit, and third inductive circuit. First inductive circuit at receiver side has a first end coupled to a first port of an antenna and a second end coupled to an input port of a receiving circuit. Second inductive circuit at transmitter side has a first end and a second end respectively coupled to output ports of a power amplifier. Third inductive circuit at antenna side has a first end coupled to a first port of the antenna and having a second end. Second inductive circuit and the third inductive circuit are disposed on an outer ring to form a ring shape and the third inductive circuit is disposed on an inner ring within the outer ring to form a spiral shape. Third inductive circuit is disposed between the second inductive circuit and the first inductive circuit.

A capacitively-coupled plasma processing apparatus includes: at least one chamber body providing chambers separated from each other; upper electrodes respectively installed in upper spaces within the chambers; lower electrodes respectively installed in lower spaces within the chambers; a high frequency power supply; a transformer including a primary coil electrically connected to the high frequency power supply, and secondary coils each of which coils having a first end and a second end; first condensers respectively connected between each of the first ends of the secondary coils and the upper electrodes; and second condensers respectively connected between each of the second ends of the secondary coils and the lower electrodes. The primary coil extends around a central axis. The secondary coils are configured to be coaxially disposed with respect to the primary coil. A self-inductance of each of the secondary coils is smaller than that of the primary coil.

An inductor circuit includes first inductive circuit, second inductive circuit, and third inductive circuit. First inductive circuit at receiver side has a first end coupled to a first port of an antenna and a second end coupled to an input port of a receiving circuit. Second inductive circuit at transmitter side has a first end and a second end respectively coupled to output ports of a power amplifier. Third inductive circuit at antenna side has a first end coupled to a first port of the antenna and having a second end. Second inductive circuit and the third inductive circuit are disposed on an outer ring to form a ring shape and the third inductive circuit is disposed on an inner ring within the outer ring to form a spiral shape. Third inductive circuit is disposed between the second inductive circuit and the first inductive circuit.

An inductor circuit includes first inductive circuit, second inductive circuit, and third inductive circuit. First inductive circuit at receiver side has a first end coupled to a first port of an antenna and a second end coupled to an input port of a receiving circuit. Second inductive circuit at transmitter side has a first end and a second end respectively coupled to output ports of a power amplifier. Third inductive circuit at antenna side has a first end coupled to a first port of the antenna and having a second end. Second inductive circuit and the third inductive circuit are disposed on an outer ring to form a ring shape and the third inductive circuit is disposed on an inner ring within the outer ring to form a spiral shape. Third inductive circuit is disposed between the second inductive circuit and the first inductive circuit.

A coin detection antenna includes a substrate and an air core coil in a track shape including a wiring pattern provided on the substrate, and a width of an air core of the air core coil in a short-side direction is equal to or less than twice a thickness of a smallest coin having a smallest thickness of coins to be detected.

An inductor circuit includes first inductive circuit, second inductive circuit, and third inductive circuit. First inductive circuit at receiver side has a first end coupled to a first port of an antenna and a second end coupled to an input port of a receiving circuit. Second inductive circuit at transmitter side has a first end and a second end respectively coupled to output ports of a power amplifier. Third inductive circuit at antenna side has a first end coupled to a first port of the antenna and having a second end. Second inductive circuit and the third inductive circuit are disposed on an outer ring to form a ring shape and the third inductive circuit is disposed on an inner ring within the outer ring to form a spiral shape. Third inductive circuit is disposed between the second inductive circuit and the first inductive circuit.