Abstract: An antenna of a radio apparatus, the directional pattern of which can be altered controllably. The antenna comprises at least one conductive element, additional from the viewpoint of the basic operation of the antenna, for shaping the directional pattern of the antenna. Such a conductive element (330, 340) is connected to signal ground at a ground point relatively near the feed point (F) of the antenna. The conductive element has a part (331) the length of which is about a quarter of the wavelength at an operating frequency of the antenna, pointing from the ground point (G) in a direction substantially opposite to the feeding direction of the radiating element (320). That part is used to equalize the directional pattern of the antenna in the receiving band. In addition, the conductive element has a second part (332) pointing from the ground point to the feeding direction of the radiating element to set a directional pattern notch at transmitting band frequencies in a desired direction.

Abstract: An antenna of a radio apparatus, the directional pattern of which can be altered controllably. The antenna comprises at least one conductive element, additional from the viewpoint of the basic operation of the antenna, for shaping the directional pattern of the antenna. Such a conductive element (330, 340) is connected to signal ground at a ground point relatively near the feed point (F) of the antenna. The conductive element has a part (331) the length of which is about a quarter of the wavelength at an operating frequency of the antenna, pointing from the ground point (G) in a direction substantially opposite to the feeding direction of the radiating element (320). That part is used to equalize the directional pattern of the antenna in the receiving band. In addition, the conductive element has a second part (332) pointing from the ground point to the feeding direction of the radiating element to set a directional pattern notch at transmitting band frequencies in a desired direction.

Abstract: The invention relates to a particular structure of high-frequency antenna, which comprises a support element (1) provided with a cylindrical coil conductor which forms a helix (2). On the support element (1) there is formed, for example by means of a conductive coating, the electrical parts of the antenna, such as the attachment points (3b) for the helix and for other parts, such as feeder lines (4), radiators (5) or impedance matching devices. By varying the number and size of the helices (2), the number and form of the feeder lines (4) and radiators (5) and the quality of any impedance matching devices, it is possible without difficulty to obtain a very wide choice of different antenna structures. The feeder lines and radiators extend, at least in part, within the helix.

Abstract: The invention relates to a double-action, two-piece antenna structure whose first antenna part, preferably a helix antenna (1), is fixedly connected to the antenna port of a radio communications set, and the second antenna port, preferably a rod antenna (2), is movable with respect to the first antenna part. In an active position, the second antenna part (2) is coupled to the first antenna part (1), forming a serial connection whose electrical length is as great as or greater than the electrical length of the first antenna part alone.

Abstract: The present invention relates to a radio frequency filter the resonators (6,7) of which are made up of a wire wound into a cylindrical coil comprising a number of turns and of a surrounding casing (41). Finger-like projections (3) of an insulating plate (1) support the conical coils from the inside, and the coupling to the resonator is from a microstrip line (8), at a tap point (21), on the insulating plate. Each cylindrical coil has, adjoining the first turn, a straight portion (2) which is parallel to the axis of the cylindrical coil and extends towards the bottom plate (44) of the filter. On the inside surface of the bottom plate (44) there is a lead (51) one end (E) of which is short-circuited and the other end open, and the tip (12) of the straight portion (2) adjoining the cylindrical coil (6) is in contact with this lead (51).