A slot antenna includes: a first electrically conductive member having a first electrically conductive surface; a second electrically conductive member having a second electrically conductive surface opposing the first electrically conductive surface; a waveguide member between the first electrically conductive member and the second electrically conductive member, the waveguide member having an electrically conductive waveguide face of a stripe shape opposing the first electrically conductive surface, the waveguide member extending in a first direction along the first electrically conductive surface; and an artificial magnetic conductor extending on both sides of the waveguide member, between the first electrically conductive member and the second electrically conductive member. The first electrically conductive member has one or more slots. At least one of the slot or slots is a complex slot having a pair of vertical portions and a lateral portion that interconnects the pair of vertical portions. The lateral portion of the complex slot opposes the waveguide face, and intersects the first direction.

A band-pass filter having a body, a rectangular waveguide, and a dielectric insert, the dielectric insert has a dielectric plate and a high temperature superconductive film in line with a plurality of rectangular windows of the same height. The waveguide has ab cross-section, a being length of the long side walls and b the length of the short side walls. Each long side wall has a fixing groove at the central portion and a rectangular recess in the fixing groove. The dielectric plate has two ends in the fixing grooves and is symmetric with a perpendicular bisecting plane of the long side wall. The rectangular recess is symmetric to the perpendicular bisecting plane and has the same length as that of the waveguide, with its width w satisfying t<w<a/2, and depth d satisfying d</4, t being total thickness of the dielectric plate and the high temperature superconductive film, and the wavelength of the central frequency of the pass-band of the band-pass filter.

Provided is a balun structure, including: a first dielectric layer, a second dielectric layer, a ground electrode, an unbalance electrode, and a balance electrode. The first dielectric layer, the ground electrode, the second dielectric layer are successively stacked, and the ground electrode has a coupling hole therein. The coupling hole extends from a surface facing the first dielectric layer to a surface facing the second dielectric layer. The unbalance electrode is disposed on a first side of the first dielectric layer, wherein the first side of the first dielectric layer is a side, distal from the ground electrode, of the first dielectric layer. The balance electrode is disposed on a first side of the second dielectric layer, wherein the first side of the second dielectric layer is a side, distal from the ground electrode, of the second dielectric layer.

Disclosed is an antenna including a radiating element, a co-planar ground plane element and a transmission line extending across at least a portion of the radiating element and the ground plane element. The transmission line includes a dielectric layer having a portion of a first major surface adjacent to the ground plane and a second major surface opposite and separated from the first surface. A shield is formed on the second major surface. At least one via extends through the dielectric layer to connect the shield to the ground plane. A feed line extends longitudinally through the dielectric layer from a feed point at a proximal end of the transmission line towards a distal end of the transmission line, the feed line being shielded along a portion of its length extending across the ground plane element by the shield.

The present disclosure relates to a balun arrangement (14) comprising a slot (5) at least partially having a crossing slot width (ws, hs) running between a first longitudinal side (6) and a second longitudinal side (7) in at least a first metallization layer (2). The balun arrangement (14) further comprises an unbalanced first port (P.sub.1) that is defined between a first connection (10) to the second side (7) of the slot (5) and a fourth connection (21) to the first side (6) of the slot (5) and a balanced second port (P.sub.2) that is that is defined between a second connection (11) to the second side (7) of the slot (5) and a fifth connection (22) to the first side (6) of the slot (5). The balun arrangement (14) also comprises a balanced third port (P.sub.3) that is defined between a third connection (12) to the first side (6) of the slot (5) and a sixth connection (23) to the second side (7) of the slot (5).

Disclosed is an antenna including a radiating element, a co-planar ground plane element and a transmission line extending across at least a portion of the radiating element and the ground plane element. The transmission line includes a dielectric layer having a portion of a first major surface adjacent to the ground plane and a second major surface opposite and separated from the first surface. A shield is formed on the second major surface. At least one via extends through the dielectric layer to connect the shield to the ground plane. A feed line extends longitudinally through the dielectric layer from a feed point at a proximal end of the transmission line towards a distal end of the transmission line, the feed line being shielded along a portion of its length extending across the ground plane element by the shield.