An oscillator oscillating a tera hertz wave includes a negative resistive element including a first semiconductor layer, a second semiconductor layer, and an active layer disposed between the first semiconductor layer and the second semiconductor layer, with a first conductor, a second conductor, and a dielectric disposed between the first conductor and the second conductor constitutes a resonator, wherein the negative resistive element is disposed between the first conductor and the second conductor, and a layer with a higher resistivity than the first semiconductor layer or the second semiconductor layer, or an amorphous layer is disposed between the negative resistive element and the dielectric.

An oscillator oscillating a tera hertz wave includes a negative resistive element including a first semiconductor layer, a second semiconductor layer, and an active layer disposed between the first semiconductor layer and the second semiconductor layer, with a first conductor, a second conductor, and a dielectric disposed between the first conductor and the second conductor constitutes a resonator, wherein the negative resistive element is disposed between the first conductor and the second conductor, and a layer with a higher resistivity than the first semiconductor layer or the second semiconductor layer, or an amorphous layer is disposed between the negative resistive element and the dielectric.

Provided is an element that can reduce a parasitic oscillation. An element used for an oscillation or a detection of a terahertz wave includes a resonance unit 108 including a first conductor 102, a second conductor 105, a dielectric 104 arranged between the first conductor and the second conductor, a first negative resistance element 101a and a second negative resistance element 101b mutually connected in parallel between the first conductor and the second conductor, a bias circuit 120 that supplies a bias voltage to each of the first negative resistance element and the second negative resistance element, and a line 103 that connects the bias circuit to the resonance unit, and the element is configured in a manner that a mutual injection locking in a positive phase between the first negative resistance element and the second negative resistance element is unstable, and a mutual injection locking in a reversed phase between the first negative resistance element and the second negative resistance element becomes stable.

Provided is an element that can reduce a parasitic oscillation. An element used for an oscillation or a detection of a terahertz wave includes a resonance unit 108 including a first conductor 102, a second conductor 105, a dielectric 104 arranged between the first conductor and the second conductor, a first negative resistance element 101a and a second negative resistance element 101b mutually connected in parallel between the first conductor and the second conductor, a bias circuit 120 that supplies a bias voltage to each of the first negative resistance element and the second negative resistance element, and a line 103 that connects the bias circuit to the resonance unit, and the element is configured in a manner that a mutual injection locking in a positive phase between the first negative resistance element and the second negative resistance element is unstable, and a mutual injection locking in a reversed phase between the first negative resistance element and the second negative resistance element becomes stable.

Apparatus for communicating across an isolation barrier. In one embodiment, the apparatus comprises a transformer having a first winding disposed on a first side of a printed circuit board (PCB) and coupled to a first local ground, and a second winding disposed on a second side of the PCB, the second side opposite to the first side, and coupled to a second local ground; a transmitter coupled to the first winding; and a receiver, coupled the second winding, that generates an output signal based on a signal received from the transmitter.

Apparatus for communicating across an isolation barrier. In one embodiment, the apparatus comprises a transformer having a first winding disposed on a first side of a printed circuit board (PCB) and coupled to a first local ground, and a second winding disposed on a second side of the PCB, the second side opposite to the first side, and coupled to a second local ground; a transmitter coupled to the first winding; and a receiver, coupled the second winding, that generates an output signal based on a signal received from the transmitter.

An oscillator oscillating a tern hertz wave includes a negative resistive element including a first semiconductor layer, a second semiconductor layer, and an active layer disposed between the first semiconductor layer and the second semiconductor layer, with a first conductor, a second conductor, and a dielectric disposed between the first conductor and the second conductor constitutes a resonator, wherein the negative resistive element is disposed between the first conductor and the second conductor, and a layer with a higher resistivity than the first semiconductor layer or the second semiconductor layer, or an amorphous layer is disposed between the negative resistive element and the dielectric.

An oscillator oscillating a tern hertz wave includes a negative resistive element including a first semiconductor layer, a second semiconductor layer, and an active layer disposed between the first semiconductor layer and the second semiconductor layer, with a first conductor, a second conductor, and a dielectric disposed between the first conductor and the second conductor constitutes a resonator, wherein the negative resistive element is disposed between the first conductor and the second conductor, and a layer with a higher resistivity than the first semiconductor layer or the second semiconductor layer, or an amorphous layer is disposed between the negative resistive element and the dielectric.

In an antenna array including first through fifth antennas, the second, first, and third antennas are arranged in this order in a first direction, and the fourth, first, and fifth antennas are arranged in this order in a second direction. A conductor layer of the second antenna is connected to a conductor layer of the first antenna via a first coupling line extending in the first direction, the conductor layer of the first antenna is connected to a conductor layer of the third antenna via a second coupling line extending in the first direction, a conductor layer of the fourth antenna is connected to the conductor layer of the first antenna via a third coupling line extending in the second direction, and the conductor layer of the first antenna is connected to a conductor layer of the fifth antenna via a fourth coupling line extending in the second direction.

An element includes a coupling line in which a first conductor layer, a dielectric layer, and a second conductor layer are stacked in this order, and which is connected to the second conductor layer in order to mutually synchronize a plurality of antennas at a frequency of a terahertz wave; and a bias line connecting a power supply for supplying a bias signal to a semiconductor layer and the second conductor layer. A wiring layer in which the coupling line is formed and a wiring layer in which the bias line is formed are different layers. The bias line is disposed in a layer between the first conductor layer and the second conductor layer.