A band-pass filter device includes a waveguide filter, a first circuit board section, a first antenna, a second circuit board section, and a second antenna. The waveguide filter includes a high-pass portion, a connection portion, and a low-pass portion. The first antenna is disposed on the first circuit board section. The second antenna is disposed on the second circuit board section. A wireless signal generated by the first antenna is transmitted through the high-pass portion, the connection portion, and the low-pass portion of the waveguide filter, and then is received by the second antenna.

A waveguide device includes: a first conductive member having an electrically conductive surface; a second conductive member having a plurality of electrically conductive rods arrayed thereon, each conductive rod having a leading end opposing the conductive surface; and a waveguide member having an electrically conductive waveguide face opposing the conductive surface, the waveguide member being disposed among the conductive rods and extending along the conductive surface. The waveguide member includes at least one of a bend and a branching portion. A measure of an outer shape of a cross section of at least one of the plurality of conductive rods that is adjacent to the bend or the branching portion, taken perpendicular to an axial direction of the at least one conductive rod, monotonically decreases from a root that is in contact with the second conductive member toward a leading end.

Embodiments of the invention include an integrated monopulse comparator assembly for use in tracking antenna applications such as an antenna feed or an antenna array. Embodiments of the monopulse comparator assembly may include four rectangular waveguide antenna inputs, four magic tees, rectangular waveguide connections, and four rectangular waveguide monopulse outputs. An embodiment of a 44 antenna array including an embodiment of an integrated monopulse comparator assembly is also disclosed.

A transmission line includes a laminated insulating body including insulating base material layers that are laminated, signal conductors provided inside the laminated insulating body and extending in a transmission direction along the insulating base material layer, and ground conductors sandwiching the signal conductors in a lamination direction via the insulating base material layers. The transmission line includes at least one curved portion that is bent along a plane orthogonal to the lamination direction. The signal conductors are separated from each other in a direction orthogonal to the transmission direction when viewed in the lamination direction and include a first signal conductor on an inner side and a second signal conductor on an outer side in the curved portion. An interval between the ground conductors sandwiching the first signal conductor is narrower than an interval between the ground conductors sandwiching the second signal conductor.

A band-pass filter device includes a waveguide filter, a first circuit board section, a first antenna, a second circuit board section, and a second antenna. The waveguide filter includes a high-pass portion, a connection portion, and a low-pass portion. The first antenna is disposed on the first circuit board section. The second antenna is disposed on the second circuit board section. A wireless signal generated by the first antenna is transmitted through the high-pass portion, the connection portion, and the low-pass portion of the waveguide filter, and then is received by the second antenna.

An antenna may include a reflector and a multi-band feed assembly. A support member may be coupled to the multi-band feed assembly to orient the multi-band feed assembly for direct illumination of the reflector. The multi-band feed assembly may include first and second feeds, each having a respective septum polarizer coupled between a respective common waveguide and a respective pair of waveguides. A housing of the support member may contain the respective septum polarizers and the respective pairs of waveguides.

According to one embodiment, a waveguide bend includes a metal block. The metal block includes a first waveguide, a second waveguide and a third waveguide. The first waveguide, the second waveguide and the third waveguide are integrally formed. The second waveguide includes a bend at which a propagation direction of a radio wave is changed. An opening size of the second waveguide is smaller than an opening size of the first waveguide. The third waveguide is provided between the first waveguide and the second waveguide. An opening size of the third waveguide is smaller than the opening size of the first waveguide and is larger than the opening size of the second waveguide.

A non-reciprocal mode converting SIW includes a first straight SIW section, a second straight SIW section, and a curved SIW section coupling the first straight SIW section to the second straight SIW section. The curved SIW section included magnetic biasing at opposed corner regions. The magnetic biasing and a curvature of the curved SIW section causes: (i) a wave in a first transverse electric (TE) mode that propagates in a forward direction from the first straight section through the curved SIW section into the second straight SIW section to convert to a second TE mode, and (ii) a wave in the first TE mode that propagates in a reverse direction from the second straight SIW section through the curved SIW section into the first straight SIW section to maintain the first TE mode.

A non-reciprocal mode converting SIW includes a first straight SIW section, a second straight SIW section, and a curved SIW section coupling the first straight SIW section to the second straight SIW section. The curved SIW section included magnetic biasing at opposed corner regions. The magnetic biasing and a curvature of the curved SIW section causes: (i) a wave in a first transverse electric (TE) mode that propagates in a forward direction from the first straight section through the curved SIW section into the second straight SIW section to convert to a second TE mode, and (ii) a wave in the first TE mode that propagates in a reverse direction from the second straight SIW section through the curved SIW section into the first straight SIW section to maintain the first TE mode.

Systems and methods which provide low-loss dielectric microstrip line (DML) circuits for use with respect to signals in the terahertz frequency range are described. Low-loss DML integrated circuits of embodiments, such as may comprise DML transmission lines, DML couplers, DML crossovers, etc., may be based on silicon technology and are adapted for signal frequencies in the range of 750-925 GHz. A DML circuit implementation may he comprised of silicon on insulator based DML structure having a silicon dioxide (SiO.sub.2) insulation layer as the middle layer of the DML, wherein the device layer (HRSi) and the handle layer (HRSi) are the top and bottom layers of the DML. A high-precision fabrication process for the SOI wafer, wherein the height of the dielectric microstrip lines can be accurately controlled, may be utilized to fabricate DML circuits of embodiments. A non-contact measurement technology may be used to test the DML circuits of embodiments.