The present invention provides a terahertz oscillator utilizing a GaN Gunn diode. A terahertz wave is generated in the active layer of the Gunn diode fabricated on GaN substrate. A GaN substrate is designed to act as a waveguide of the terahertz wave. Since the waveguide and the Gunn diodes are integrated, the terahertz wave generated in the active layer couples well with the waveguide made of the GaN substrates. The terahertz wave is emitted from the edge of the waveguide efficiently. To ensure high-reliability through reduction of radiation loss and mitigation of electromigration of anode metal, a GaN substrate with low dislocation density is used. The dislocation density of the GaN substrate is less than 1×10.sup.6 cm.sup.−2. Particularly, usage of a GaN substrate made by the ammonothermal method is preferred.

A terahertz module includes: a terahertz chip which includes an active device which emits a terahertz wave; and a dielectric substrate coupled to the terahertz chip. The terahertz chip includes a semiconductor substrate. The active device is disposed on an upper surface of the semiconductor substrate. A cutout is formed in a portion of a first side surface, among a plurality of side surfaces of the dielectric substrate, the cutout extending from an upper side of the first side surface to a lower side of the first side surface. The terahertz chip is fit into the cutout in such a direction that the upper surface of the semiconductor substrate is parallel to the first side surface and the semiconductor substrate is arranged in a bottom side of the cutout.

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.

Terahertz device A1 includes first resin layer 21, columnar conductor 31, wiring layer 32, terahertz element 11, second resin layer 22, and external electrode 40. Resin layer 21 includes first resin layer obverse face 211 and first resin layer reverse face 212. Columnar conductor 31 includes first conductor obverse face 311 and first conductor reverse face 312, penetrating first resin layer 21 in z-direction. Wiring layer 32 spans between first resin layer obverse face 221 and first conductor obverse face 311. Terahertz element 11 includes element obverse face 111 and element reverse face 112, and converts between terahertz wave and electric energy. Second resin layer 22 includes second resin layer obverse face 221 and second resin layer reverse face 222, and covers wiring layer 32 and terahertz element 11. External electrode 40, disposed offset in a direction first resin layer reverse face 222 faces with respect to first resin layer 32, is electrically connected to columnar conductor 31. Terahertz element 11 is conductively bonded to wiring layer 32.

In an electromagnetic wave generation device including a plurality of electromagnetic wave generation elements, an instantaneous maximum power consumption during an electromagnetic wave generation operation is reduced. Specifically, the electromagnetic wave generation device includes a plurality of electromagnetic wave generation elements that are divided into a plurality of groups, and a control unit that causes the plurality of electromagnetic wave generation elements to oscillate while shifting a timing in units of group. For example, the control unit causes the plurality of electromagnetic wave generation elements to oscillate such that when the number of the plurality of groups is n, an oscillation start timing of the group that performs mth oscillation (m is a natural number equal to or larger than 2 and equal to or smaller than n) is the same timing as or after an oscillation end timing of the group that performs (m−1)th oscillation.

An antenna apparatus comprises: a first substrate including an antenna array in which a plurality of active antennas each including an antenna and a semiconductor structure configured to generate or detect an electromagnetic wave are provided, and a wiring electrically connected to the plurality of active antennas; and a second substrate stacked on the first substrate and including a control circuit of the antenna array, wherein the first substrate and the second substrate are bonded at a bonding surface, the control circuit is electrically connected to the antenna array via the wiring, and the control circuit of the second substrate controls oscillations of the plurality of active antennas of the first substrate.

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.

Terahertz device includes first resin layer, columnar conductor, wiring layer, terahertz element, second resin layer, and external electrode. Resin layer includes first resin layer obverse face and first resin layer reverse face. Columnar conductor includes first conductor obverse face and first conductor reverse face, penetrating first resin layer in z-direction. Wiring layer spans between first resin layer obverse face and first conductor obverse face. Terahertz element includes element obverse face and element reverse face, and converts between terahertz wave and electric energy. Second resin layer includes second resin layer obverse face and second resin layer reverse face, and covers wiring layer and terahertz element. External electrode, disposed offset in a direction first resin layer reverse face faces with respect to first resin layer, is electrically connected to columnar conductor. Terahertz element is conductively bonded to wiring layer.

A broadband terahertz fourth-harmonic mixer circuit, a mixer and a method wherein the broadband terahertz fourth-harmonic mixer circuit includes a radio frequency signal coupled transmission unit, nonlinear device, local oscillator filter, local oscillator signal coupled transmission unit and intermediate frequency filter unit which are sequentially connected; and further includes a radio frequency input port, local oscillator input port and intermediate frequency output port, where the radio frequency input port is connected to the radio frequency signal coupled transmission unit, the local oscillator input port is connected to the local oscillator signal coupled transmission unit, the intermediate frequency output port is connected to an output end of the intermediate frequency filter unit, and the local oscillator filter is of a two-level cascaded filter structure.

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.