Electromagnetic wave oscillator having multi-tunnel and electromagnetic wave generating apparatus including the electromagnetic wave oscillator

An electromagnetic wave oscillator comprising:

• a first waveguide which has a folded structure such that a path traveled by an electromagnetic wave through the first waveguide crosses an axial direction a plurality of times;
• an electron beam tunnel through which an electron beam passes, wherein the electron beam tunnel extends along the axial direction;
• at least one auxiliary tunnel which extends parallel to the electron beam tunnel;
• a second waveguide comprising a first end connected to the first waveguide and a second end comprising an electromagnetic wave output port;
• an electron beam input port which is connected to the first end of the electron beam tunnel and on which the electron beam is incident;
• and
• an electron beam discharge port which is connected to the second end of the electron beam tunnel and from which the electron beam is discharged,
• wherein the second waveguide comprises a bend of about 90 degrees and has a tapered structure in which a width of the second waveguide increases from the first end to the second end thereof.

An electromagnetic wave generating apparatus comprising:

• an electromagnetic wave oscillator which generates an electromagnetic wave;
• an electron gun which supplies an electron beam to the electromagnetic wave oscillator;
• and
• a collector which collects the electron beam discharged from the electromagnetic wave oscillator,
• wherein the electromagnetic wave oscillator comprises:
• a first waveguide which has a folded structure such that a path traveled by an electromagnetic wave through the first waveguide crosses an axial direction a plurality of times;
• an electron beam tunnel through which an electron beam passes, wherein the electron beam tunnel extends along the axial direction;
• and
• at least one auxiliary tunnel which extends parallel to the electron beam tunnel,
• wherein the electromagnetic wave oscillator is configured to cause one of a millimeter wave, a sub-millimeter wave, and an electromagnetic wave in a terahertz frequency band passing through the first waveguide to obtain energy by interaction with the electron beam that passes through the electron beam tunnel.

An electromagnetic wave oscillator comprising:

• a waveguide which extends in a wave-like shape from a first end to a second end, such that the waveguide crosses an axial direction a plurality of times, wherein the axial direction is a direction from the first end to the second end;
• an electron beam tunnel which guides an electron beam, wherein the electron bean tunnel extends parallel to the axial direction;
• and
• an auxiliary tunnel which extends parallel to the axial direction,
• wherein the waveguide includes a plurality of parallel barrier ribs arranged along the axial direction, each barrier rib of the plurality of barrier ribs being interdigitated with other adjacent barrier ribs of the plurality of barrier ribs such that the plurality of barrier ribs are alternately disposed in opposite directions, and
• wherein the electron beam tunnel and the auxiliary tunnel perforate the plurality of parallel barrier ribs of the waveguide,
• wherein the thickness of first portions of the barrier ribs is smaller than a thickness of second portions of the barrier ribs such that a coupled cavity is formed between the first portions of two adjacent barrier ribs extending in the same direction, and wherein the electron beam tunnel and the auxiliary tunnel perforate the second portions of the barrier ribs.