Abstract: Provided is a dual-band multimode antenna feed for a high-frequency band and a low-frequency band. The feed includes four high-frequency waveguide ports, where each high-frequency waveguide port is connected to a respective high-frequency input/output waveguide. Each high-frequency input/output waveguide includes a high-frequency waveguide aperture facing a first section for mixing electromagnetic modes in the E-plane. The first section is connected to a second section for mixing electromagnetic modes in the H-plane. The feed further includes a low-frequency waveguide port connected to a low-frequency input/output waveguide. A filter is arranged inside the first section to be transparent for plane wave modes exhibited at lower frequencies and reflecting for plane wave modes exhibited at higher frequencies.

Abstract: Provided is a dual-band multimode antenna feed for a high-frequency band and a low-frequency band. The feed includes four high-frequency waveguide ports, where each high-frequency waveguide port is connected to a respective high-frequency input/output waveguide. Each high-frequency input/output waveguide includes a high-frequency waveguide aperture facing a first section for mixing electromagnetic modes in the E-plane. The first section is connected to a second section for mixing electromagnetic modes in the H-plane. The feed further includes a low-frequency waveguide port connected to a low-frequency input/output waveguide. A filter is arranged inside the first section to be transparent for plane wave modes exhibited at lower frequencies and reflecting for plane wave modes exhibited at higher frequencies.

Abstract: The invention relates to an antenna. The antenna comprises a feed line having first and second ends on opposite sides of the feed line, wherein a transmission axis is defined as the axis extending between the first and second ends of the feed line. Further, the antenna comprises a plurality of antenna elements arranged along the feed line, protruding from the transmission axis. The antenna also comprises a first port at the first end of the feed line, wherein, at a first part of the antenna, the feed line, from the first port towards a reference point along the transmission axis, comprises antenna elements of gradually increasing length, configured to radiate in a first direction along the transmission axis from the reference point towards the first port during excitation in the first port.

Abstract: The invention relates to an antenna. The antenna comprises a feed line having first and second ends on opposite sides of the feed line, wherein a transmission axis is defined as the axis extending between the first and second ends of the feed line. Further, the antenna comprises a plurality of antenna elements arranged along the feed line, protruding from the transmission axis. The antenna also comprises a first port at the first end of the feed line, wherein, at a first part of the antenna, the feed line, from the first port towards a reference point along the transmission axis, comprises antenna elements of gradually increasing length, configured to radiate in a first direction along the transmission axis from the reference point towards the first port during excitation in the first port.

Abstract: The present disclosure relates to a balun suitable for realizing a wideband transition in the radio frequency band from an unbalanced transmission line to a balanced transmission line. The balun comprises an input terminal; a two conductor output terminal; and a layered structure comprising a number of conducting layers and dielectric layers alternatingly arranged on top of each other. The layered structure comprises at least one ground plane layer and at least one signal transmission layer. The input terminal has a signal connection point and a screen connecting point. An unbalanced signal path is connected to the signal connection point and the screen connecting point of the input terminal. A balanced signal path is connected to the output terminal and being part of the layered structure. A balun transition region transforms the signal from an unbalanced signal to a balanced signal.

Abstract: The present disclosure relates to a balun suitable for realising a wideband transition in the radio frequency band from an unbalanced transmission line to a balanced transmission line. The balun comprises an input terminal; a two conductor output terminal; and a layered structure comprising a number of conducting layers and dielectric layers alternatingly arranged on top of each other. The layered structure comprises at least one ground plane layer and at least one signal transmission layer. The input terminal has a signal connection point and a screen connecting point. An unbalanced signal path is connected to the signal connection point and the screen connecting point of the input terminal. A balanced signal path is connected to the output terminal and being part of the layered structure. A balun transition region transforms the signal from an unbalanced signal to a balanced signal.

Abstract: An antenna frame for reducing radar cross section of a vehicle provided with a flat microstrip patch antenna array comprising a number of microstrip patches arranged in an array pattern, the antenna frame: —being arranged to surround the outer periphery of the flat antenna array —the frame comprising a first conductive sheet; —the first conductive sheet extending from the most peripheral patches and outward in a sloping manner; wherein dielectric and magnetic absorbent material are arranged to improve impedance transition from a point of the antenna to a point on the periphery of the frame, which is also contemplated as adjoining a vehicle fuselage.

Abstract: An antenna frame for reducing radar cross section of a vehicle provided with a flat microstrip patch antenna array comprising a number of microstrip patches arranged in an array pattern, the antenna frame:—being arranged to surround the outer periphery of the flat antenna array—the frame comprising a first conductive sheet;—the first conductive sheet extending from the most peripheral patches and outward in a sloping manner; wherein dielectric and magnetic absorbent material are arranged to improve impedance transition from a point of the antenna to a point on the periphery of the frame, which is also contemplated as adjoining a vehicle fuselage.

Abstract: An antenna device including a reflectarray with array antenna elements, and an outer feed provided with a waveguide and a widening funnel which in a widened end carries a waveguide aperture for illumination of the reflectarray. The antenna device eliminates or at least reduces a position dependence of an antenna lobe with respect to frequency. Furthermore, the antenna device presents a low monostatic radar cross section and compactness. To this end the antenna device is fed offset and is provided with a device for movement of a phase center of the antenna with a frequency relative to the waveguide aperture of the feed in the vicinity of the waveguide aperture.

Abstract: An antenna device including a reflectarray with array antenna elements, and an outer feed provided with a waveguide and a widening funnel which in a widened end carries a waveguide aperture for illumination of the reflectarray. The antenna device eliminates or at least reduces a position dependence of an antenna lobe with respect to frequency. Furthermore, the antenna device presents a low monostatic radar cross section and compactness. To this end the antenna device is fed offset and is provided with a device for movement of a phase center of the antenna with a frequency relative to the waveguide aperture of the feed in the vicinity of the waveguide aperture.

Abstract: The invention relates to a method for conversion of waveguide modes from a mode of type TM01 to mode of type TE11 for transmission of power within the microwave range. The invention also relates to a mode-converting arrangement and an antenna arrangement with such a mode converting arrangement. The mode-converting arrangement comprises an incoming waveguide (1) for reception of power of the type TM01-an outgoing waveguide (6) for outputting power of mode type TE11 and a waveguide-mode-converting section (2-5) arranged between the incoming and outgoing waveguides. According to the invention, incoming power of mode type TM01 is divided in an input section (2) between two or more waveguides with cross-sections in the shape of circle sectors.

Abstract: The invents relates to a method for conversion of waveguide modes from a mode of type TM01 to mode of type TE11 for transmission of power within the microwave range. The invention also relates to a mode-converting arrangement and an antenna arrangement with such a mode converting arrangement. The mode-converting arrangement comprises an incoming waveguide (1) for reception of power of the type TM01-an outgoing waveguide (6) for outputting power of mode type TE11 and a waveguide-mode-converting section (2-5) arranged between the incoming and outgoing waveguides. According to the invention, incoming power of mode type TM01 is divided in an input section (2) between two or more waveguides with cross-sections in the shape of circle sectors.

Abstract: An antenna device for emitting and/or receiving electromagnetic radiation, such as radar radiation in a car radar apparatus is provided. Sweeping is realized by means of a fixed feeder and a rotatable reflector. The reflector is driven by a drive motor and its motion is monitored by a tachometer. The drive motor and the tachometer are constituted by so-called flag motors which are mutually motionally coupled to each other by mechanical means.