Abstract: The invention relates to a phase sequencing three-phase network comprising a first side connected to a second side via the network. The first side comprises one endpoint (EP1) and the second side comprises three endpoints (EP2, EP3, and EP4). The network comprises five nodes (NP1-NP5) interconnected via feed line sections (FP1-FP10) comprising at least one transmission line section (R11-R102) each. The invention further relates to an optimization method for the network for deciding characteristic impedance and length of each transmission line section (R11-R102).

Abstract: A waveguide polarizer for converting between a linearly polarized electromagnetic field in a first waveguide and a circularly polarized electromagnetic field in a second waveguide is provided. The waveguide polarizer includes a structure interconnecting the first and second waveguide which includes a waveguide excitation arrangement with a bifilar helical shape. A circularly polarized antenna arranged to be connected to the first waveguide of the waveguide polarizer and a satellite arrangement are also provided.

Abstract: A waveguide polarizer for converting between a linearly polarized electromagnetic field in a first waveguide and a circularly polarized electromagnetic field in a second waveguide is provided. The waveguide polarizer includes a structure interconnecting the first and second waveguide which includes a waveguide excitation arrangement with a bifilar helical shape. A circularly polarized antenna arranged to be connected to the first waveguide of the waveguide polarizer and a satellite arrangement are also provided.

Abstract: The invention relates to a phase sequencing three-phase network comprising a first side connected to a second side via the network. The first side comprises one endpoint (EP1) and the second side comprises three endpoints (EP2, EP3, and EP4). The network comprises five nodes (NP1-NP5) interconnected via feed line sections (FP1-FP10) comprising at least one transmission line section (R11-R102) each. The invention further relates to an optimization method for the network for deciding characteristic impedance and length of each transmission line section (R11-R102).

Abstract: A mechanically simple dual-frequency (or wide band) quadrifilar helix antenna (1). It includes four helix shaped radiating elements (2-5) where each helix element consists of two or more parallel helices (2a, 2b, 3a, 3b, 4a, 4b, 5a, 5b) of different lengths that are in galvanic contact at, or close to, the feeding point (2c, 3c, 4c, 5c). The four feeding points (2c, 3c, 4c, 5c) of the helix elements (2-5) are located at the bottom of the helix, meaning that the feedings of the helix elements are located at the end (6) of the helix pointing in the direction opposite to the direction of its main radiation.