Abstract: An antenna intended to be used in a small and foldable radio device and a radio device which has an antenna according to the invention. The radiating element (120) in the antenna is a conductor having an outline shaped substantially like a rectangle and defining a plane which is perpendicular to the ground plane (GND) situated on the circuit board (111) of the radio device. The radiating element is so narrow that it fits inside the foldable device in the perpendicular position. The element is connected to the radio device only by its feed point (F). Resonating frequencies of the element can be arranged in desired locations besides by shaping the element, also by means of discrete components (L, C). The matching of the antenna is easily arranged by providing an appropriate distance between the radiating element and ground plane. In an operating situation, an antenna gain is achieved which is considerably higher than that of a PIFA of equal height.

Abstract: The invention relates to a multiband antenna which finds utility particularly in mobile stations. The antenna structure includes a PIFA-type antenna positioned inside the covers of a mobile station, which antenna includes a slot radiator (231). In the planar element there is a second slot (232) so that, viewed from a feed point (F), two radiating conductive branches (B1, B2) of different lengths are formed. Each of the three radiators has a separate operating band of its own. The structure also includes a whip element (211) movable with respect to the PIFA part. When the whip element is pulled out, its lower end is galvanically coupled with the shorter branch of the planar element, with its relatively narrow side branch (B12). The whip enhances the operation of the antenna especially in the lowest operating band. The influence of the pulled-out whip on the location of the uppermost operating band is compensated for by a third slot (233) in the planar element.

Abstract: An internal planar antenna for small radio apparatuses. The ground plane (310) of the planar antenna is shaped such that it improves the matching of the antenna. The shaping may be done by means of one or more slots (315, 316) in the ground plane. The slot suitably changes the electrical length of the ground plane as viewed from the short-circuit point (S) so that the ground plane will function as a radiator in an operating band of the antenna. Also the slot (331) in the ground plane can be arranged to function as an additional radiator in an operating band of the antenna. Antenna gain will increase as the matching is improved, and the upper band of a dual band antenna, for example, can be made broader.

Abstract: A control system for the transmitting power of a multiband antenna of especially a mobile station. The antenna (300) has at least two radiating elements (B31, B32) corresponding to different operating bands. A separate part is arranged for each element in the antenna switch of a radio device using TDD technology. When one radiating element (B31) is connected to a transmitter (TX1), the other radiating element (B32) is connected to a control circuit (DET, PCU) for a radio-frequency power amplifier (PA1) of the transmitter. By an electromagnetic coupling (CP) between the radiating elements is then produced to the control circuit a signal (M1) indicating the transmitting power, and the transmitting power can be kept as desired by controlling the power amplifier. The electromagnetic coupling between the elements is arranged suitable in view of the power control.

Abstract: Internal planar antenna especially applicable to mobile communication devices. A PIFA-type planar antenna is fed coaxially-like. This means that the feed conductor (321) of a radiating plane (310) is surrounded by a shield conductor (322) galvanically connected to the ground plane (GND) for the length between these planes. The shield conductor at the same time serves as a short circuit conductor for the antenna. The antenna is matched by means of a matching slot (317) going between the connection points of the feed and short circuit conductors, and/or of the shape of the short circuit conductor. A feed arrangement at issue increases antenna gain without increasing the SAR value of the antenna.

Abstract: The invention relates to a method of manufacturing a structure suitable as an internal antenna in small radio devices, and an antenna element to which the method is applied. The antenna element comprises a radiating plane and additionally e.g. supportive elements, a feed conductor and short-circuit conductor as well as extensions to increase capacitance. The antenna element is fabricated by first extruding from a billet an antenna billet, and working the latter as required. The antenna billet may be symmetrical so that two antenna elements will be produced when it is cut in half. Advantageously the antenna element is fabricated so as to conform with the covering of the device in which it is placed. It may also be part of a covering of a device. The manufacturing costs of the antenna element are relatively low and the radio characteristics of the element are good. An antenna structure employing the element has got few separate parts and is mechanically firm and space-conserving.

Abstract: The invention relates to an antenna structure (400) to be placed inside in particular small radio apparatus. A conventional PIFA-type structure is extended by arranging a structural part (415) adding to the capacitance between the radiating plane (420) and ground plane (410) relatively close to the feed point (F) of the antenna. The structural component may be a projection extending from the radiating plane towards the ground plane or vice versa. An advantage of the invention is that it achieves a significant increase in the antenna bandwidth without increasing the size of the antenna. Another advantage of the invention is that the structure according to it is simple and the increase in the manufacturing costs is relatively low.

Abstract: The invention pertains to an antenna construction of at least two frequency bands comprising at least a whip antenna. A dielectric block (33) with a relatively high permittivity is installed into the whip antenna (32) at a location in which there is a voltage maximum at a harmonic of the basic resonance frequency of the antenna. The dielectric medium shifts the harmonic in question downwards. The arrangement is realized in such a manner that the basic resonance frequency of the whip antenna falls on the operating frequency band of one network, and the harmonic in question falls on the operating frequency band of a desired second network. The construction may further comprise a PIFA antenna (34) the operating frequency of which is the same as the upper operating frequency of the whip antenna. Thus the degradation of the function of the PIFA that can be caused by the user's hand will not substantially degrade the connection since the whip, too, operates in the operating frequency band of the PIFA.

Abstract: The invention relates to a multiband antenna which finds utility particularly in mobile stations. The antenna structure includes a PIFA-type antenna positioned inside the covers of a mobile station, which antenna includes a slot radiator (231). In the planar element there is a second slot (232) so that, viewed from a feed point (F), two radiating conductive branches (B1, B2) of different lengths are formed. Each of the three radiators has a separate operating band of its own. The structure also includes a whip element (211) movable with respect to the PIFA part. When the whip element is pulled out, its lower end is galvanically coupled with the shorter branch of the planar element, with its relatively narrow side branch (B12). The whip enhances the operation of the antenna especially in the lowest operating band. The influence of the pulled-out whip on the location of the uppermost operating band is compensated for by a third slot (233) in the planar element.

Abstract: The invention relates to a multiband antenna structure suitable for mobile stations in particular. The radiating elements of the antenna include not only a helix (210) but also the joining piece (220) that attaches the helix to the apparatus. The helix is shaped such that the distance between its conductor turns varies. The electrical length of the joining piece is increased e.g. by means of a conductive projection (226) that remains within the covering of the apparatus. By suitably dimensioning the parts, at least five of the resonances that the helix and joining piece have together and separately are arranged at useful points on the frequency scale. The structure according to the invention is despite the several bands simple and relatively low in production costs.

Abstract: The invention relates to a planar antenna structure in small-sized radio apparatus. A layer of dielectric material, the dielectric constant of which is relatively high, is arranged outwards of the plane of the outer surface of the radiating element of a planar inverted F antenna, or PIFA. The layer is located so as to cover at least the areas in which the electric field is the strongest when the antenna resonates. In the case of dual-band antenna, the slot in the radiating element is made advantageously so wide that the effect of the coupling between the branches (A1, A2) of the element is small. An antenna according to the invention can be made smaller in size and at least as good in its electrical characteristics as a corresponding prior-art antenna. Alternatively, the electrical characteristics of the antenna can be substantially improved without making the size of the antenna bigger.

Abstract: The invention relates to an antenna structure to be installed inside small-sized radio apparatus. A conventional PIFA-type structure is extended such that on top of the ground plane (210) there will be instead of one at least two radiating planes (220, 230) on top of each other. There is between them dielectric material (240) to reduce the size of the lower radiator and to improve the band characteristics. Likewise, there is dielectric material (250) on top of the uppermost radiating plane so as to bring one resonance frequency of the antenna relatively close to another resonance frequency in order to widen the band. Advantageously the radiating planes are in galvanic contact (203) with each other. The invention accomplishes a greater increase in the antenna bandwidth as compared to that achieved by placing the only radiating plane at a distance from the ground plane equal to that of the upper radiating plane according to the invention.

Abstract: The invention relates to the structure of a dual-band planar antenna. The radiating element (210) in a planar antenna (200) has a slot consisting of two portions of different widths. One end of the wider portion (216) of the slot is close to the feed point (S) of the radiating element. The narrower portion (217) of the slot starts from a point in the wider portion and extends to the edge of the radiating element. The portions of the slot are advantageously straight. The order of magnitude of the ratio (w1/w2) of the widths of the portions is three. An advantage of the invention is that the bandwidths of a dual-band planar antenna are larger than those of prior-art structures of the same size.

Abstract: An antenna (400; 600) for transmitting and receiving radio-frequency signals comprises a cylindrical coil conductor (601) having a turn A and a turn B and between them other turns. The pitch (x1) of turn A is unequal to the pitch (x2) of said turn B, and the pitches of the other turns between turns A and B are in the order of magnitude between the pitches of turns A and B.

Abstract: The invention relates to a multiband antenna structure suitable for mobile stations in particular. The radiating elements of the antenna include not only a helix (210) but also the joining piece (220) that attaches the helix to the apparatus. The helix is shaped such that the distance between its conductor turns varies. The electrical length of the joining piece is increased e.g. by means of a conductive projection (226) that remains within the covering of the apparatus. By suitably dimensioning the parts, at least five of the resonances that the helix and joining piece have together and separately are arranged at useful points on the frequency scale. The structure according to the invention is despite the several bands simple and relatively low in production costs.

Abstract: The invention relates to planar antennas the structural components of which include a parasitic element. The antenna structure comprises a PIFA-type structure (230, 210, 202) to be placed inside the covers of a mobile station. The PIFA is fed parasitically e.g. through a conductive strip (240) placed on the same insulating board. The feed conductor (203) of the whole antenna structure is in galvanic contact with this feed element; a short-circuit point the feed element doesn't have. The feed element (240) also serves as an auxiliary radiator. The resonance frequencies of the antenna elements or their parts are arranged according to need so as to overlap, to be close to each other or to be relatively wide apart. The structure may also comrise a whip element in connection with the feed element. According to the invention, a relatively simple structure provides a reliable dual resonance and, hence, a relatively wideband antenna when the resonances are close to each other.

Abstract: A radio device comprises an antenna for transmitting and receiving radio frequency signals. The antenna comprises a radiating antenna element (201, 602, 701) and a dielectric protective casing (202, 703) attached to each other, whereby the dielectric protective casing substantially encloses the antenna element. Further the radio device comprises a protective casing (205) of the radio device for mechanically supporting the radio device and for protecting its electrical components, and a printed circuit board (203) within the protective casing for connecting the electrical components to the radio device and for forming the electrical connections between the components. The antenna is mechanically fastened to the radio device with the aid of counterpart fastening shapes (301, 302, 303, 304, 305, 306, 307, 308) located in the antenna's protective casing and in the radio device's protective casing.

Abstract: The antenna (D) of a radio telephone radiates electromagnetic RF radiation which is directed to a dielectric body block (10) according to the invention. By means of an inner and an outer conductor (1, 2) formed on the surface of the block a signal carried by the electromagnetic radiation is coupled to a coaxial cable (12) which takes it to an external antenna.

Abstract: An antenna construction comprises a feed conductor (11, 21) and an antenna element (12, 22, 24, 25, 26, 27) which has a first end and a second end. The feed conductor is substantially electrically unshielded and coupled to the antenna element at a tapping point (13, 23) located between the first end and second end of the antenna element the tapping point dividing the antenna element into two portions having unequal electrical lengths. The antenna element may be a helix (12), a whip (22) or another known two-ended antenna element or a combination of those.

Abstract: A combination antenna has two antenna parts (8; 9, 9a, 17) and a connector part (10) to connect them to a radio apparatus. The first antenna part is a whip antenna and the second antenna part comprises a planar surface and a conductive pattern (16) formed on it to transmit and receive radio-frequency radiation. When the antenna parts are mechanically coupled to the connector part the plane surface, which includes a radiating conductive pattern, is separated from said first antenna part. In addition, the second antenna part or another part of the construction may include a plane surface with a plating on it, which in the normal operating position protects the user's head from radiation.