Abstract: A multi-frequency antenna having a small size, light weight and excellent productivity and being suitable for transmitting and receiving electric waves in Ghz band, is constituted such that an orthogonal coordinate X-Y is set, a first antenna element 21 having an electric wavelength of ?a/4 and a second antenna element 22 having an electric wavelength of ?b/4 are placed in parallel to the X axis respectively, one edge of each of said elements is positioned near the Y axis, said two elements are connected electrically with a ground plate 8 by a short-circuit line 4 along the Y axis, a point where an impedance is 50 ? (code 50) of the first antenna element 21 and a point where an impedance is 50 ? of the second antenna element 22 are made to be a power feed point respectively, and said power feed points are connected with a coaxial cable 7 through a power feed line 6.

Abstract: A multi-frequency antenna having a small size, light weight and excellent productivity and being suitable for transmitting and receiving electric waves in Ghz band, is constituted such that an orthogonal coordinate X-Y is set, a first antenna element 21 having an electric wavelength of &lgr;a/4 and a second antenna element 22 having an electric wavelength of b/4 are placed in parallel to the X axis respectively, one edge of each of said elements is positioned near the Y axis, said two elements are connected electrically with a ground plate 8 by a short-circuit line 4 along the Y axis, a point where an impedance is 50&OHgr; (code 50) of the first antenna element 21 and a point where an impedance is 50&OHgr; of the second antenna element 22 are made to be a power feed point respectively, and said power feed points are connected with a coaxial cable 7 through a power feed line 6.

Abstract: To make improvements in a conventional slotted bow tie antenna to make it possible to (a) broaden the tuning frequency band, (b) function as a dual band antenna, without diminishing the “advantage of enabling a thin shape and possessing directivity”. When the symmetrical axis in the longitudinal direction of the bow tie shaped slot is set as x, and the symmetrical axis perpendicular thereto is set as y, a narrow and long parasitic element is placed over and across in the y axis direction, and this parasitic element is insulated electrically from a metal foil provided with a slot, using an insulator, for example. Further, by using two parasitic elements and arranging them in parallel while electrically insulating them from each other, the antenna can also function as a dual band antenna.

Abstract: To make improvements in a conventional slotted bow tie antenna to make it possible to (a) broaden the tuning frequency band, (b) function as a dual band antenna, without diminishing the “advantage of enabling a thin shape and possessing directivity”. When the symmetrical axis in the longitudinal direction of the bow tie shaped slot is set as x, and the symmetrical axis perpendicular thereto is set as y, a narrow and long parasitic element is placed over and across in the y axis direction, and this parasitic element is insulated electrically from a metal foil provided with a slot, using an insulator, for example. Further, by using two parasitic elements and arranging them in parallel while electrically insulating them from each other, the antenna can also function as a dual band antenna.

Abstract: Provides an antenna for a radio telephone whereby, in a state wherein the rod-shaped antenna is extended to outside the case of the radio telephone, the effects of the human body are negligible and emission of radio waves at an angle close to the horizontal direction is possible, and in a state wherein the rod-shaped antenna is retracted within the case, no unwanted radiation is produced. For this purpose, a helical antenna 20 having an electrical length of &lgr;/4 and a rod-shaped antenna 10 extendable and retractable with respect to the case through the hollow central portion of the helical antenna 20 and having an electrical length of about 3&lgr;/8 and inductive reactance are electrically coupled by means of an electrostatic coupling portion 30 having capacitive reactance such that, in the state wherein the rod-shaped antenna 10 is extended from the case 50, the inductive reactance of the rod-shaped antenna 10 is cancelled out.

Abstract: Provides an antenna for a radio telephone whereby, in a state wherein the rod-shaped antenna is extended to outside the case of the radio telephone, the effects of the human body are negligible and emission of radio waves at an angle close to the horizontal direction is possible, and in a state wherein the rod-shaped antenna is retracted within the case, no unwanted radiation is produced. For this purpose, a helical antenna 20 having an electrical length of &lgr;/4 and a rod-shaped antenna 10 extendable and retractable with respect to the case through the hollow central portion of the helical antenna 20 and having an electrical length of about 3&lgr;/8 and inductive reactance are electrically coupled by means of an electrostatic coupling portion 30 having capacitive reactance such that, in the state wherein the rod-shaped antenna 10 is extended from the case 50, the inductive reactance of the rod-shaped antenna 10 is cancelled out.

Abstract: A retractable broad-band antenna for a portable telephone which includes a first antenna element which resonates in the lower region of the frequency band, a second antenna element which is coupled in series to the first antenna element via electrostatic capacitance and resonates in the higher region, and a call-receiving third antenna element mounted to the tip end of the second antenna element. The first and second antenna elements are shortened antenna elements in a form of helical coils. The first antenna element has an electrical length of .lambda.L/8 and is a non-grounded type having broad band characteristics by means of a matching device; and the second element has an electrical length of .lambda.H/2 wherein .lambda.H and .lambda.L are respectively the wave lengths at a center frequency of the higher and lower region of the frequency band used.

Abstract: An antenna mount 31 consisting of a hollow bulging member is formed so as protrude locally from the top of a portable telephone housing 30. A first antenna 10 with an electrical length of .lambda./4 is provided inside the antenna mount so that the base end Q of the first antenna is connected to a feeder cable 15. A second antenna 20 with an electrical length of 3 .lambda./4 is installed parallel to the first antenna 10 at a prescribed distance from the first antenna so that the second antenna can be freely extended from and retracted into the housing 30 via the antenna mount 31 and so that the base end 23 of the second antenna 20 is connected to the earthing means 32 of the housing 30 when the second antenna is extended from the housing 30, thus providing a J-form antenna formed by the first and second antennas 10 and 20. It is desirable that the first and second antennas 10 and 20 each be equipped with an element-shortening means.

Abstract: A two-wave antenna for telephones used in vehicles which includes two radiating elements in which one end of each of the two radiating elements is respectively connected to one end of a single phase coil and the effective radiating lengths of the two radiating elements are respectively 1/2 .lambda..sub.1 to 5/8 .lambda..sub.1 and an electrical length of the phase coil is 3/2 .lambda..sub.1 to 5/4 .lambda..sub.1 so that currents of the same phase and two frequency bands are carried in the two radiating elements and wherein .lambda..sub.1 is the wavelength of the first band.

Abstract: An M-type car antenna for traffic information communication systems including an antenna element having a length which is one-half of the wavelength of the radio way used in the information communication systems, and a connector which is connected via an electrostatic coupling to the center-of the antenna element, the impedance matching and feeding being carried out by the connector. In this antenna, the voltage polarity of the connector at the coupling point and that of the center of the antenna element are set to be opposite from each other, and the electric current in the antenna element and that in the connector are set to be in the same direction. Thus, the M-type antenna is compact and easy to manufacture with stable antenna characteristics.

Abstract: [Object] To provide a method of manufacturing a helical antenna for satellite communications which has no local bent, etc. in the completed helical coil even though the conductor wire used is of an extremely pliable material, so that a high-quality helical antenna for use in satellite communications is obtained.[Structure] A winding frame 10 in which supporting elements 12 are projected in the form of a cross from the outer circumferential surface of a rod-form base 11 is first obtained. Wedge members 71 through 74, each of which having a configuration of a cylindrical body divided into four sections along its axis, are installed between the supporting elements 12. Then, with the cylindrical surfaces of the wedge members 71 through 74 being used as a winding guide, a conductor wire is wound in helical form through conductor wire installation grooves 13 formed on the edges of the supporting elements 12. Thus, a helical coil 20 is formed.

Abstract: A three-wave antenna for vehicles which includes a monopole antenna element which has an electrical length of approximately 1/4 of the wavelength in the FM broadcast band along with a double sleeve used to prevent current flow and with a second double sleeve used for phase adjustment that are installed coaxially with the antenna element. The positional relationships between the inner and outer cylinders of each one of the first and second double sleeves relative to the antenna element are respectively specified.

Abstract: The antenna of the present invention includes an ultrashort antenna element which has an electrical length of lambda/2, a transmission path one end of which is connected to the base of the antenna element, a ground plane obtained from a sheet-form conductive member with an electrical length of lambda/4 which is bent into a U-shape so that first and second portions face each other with the first portion being installed parallel to the transmission path in close proximity to the transmission path so as to create a capacitive coupling with the transmission path, a capacitive coupling member installed at one end of the first portion so that a capacitive coupling is formed between the capacitive coupling member and ground and a coaxial cable with its central conductor connected to an other end of the transmission path and its outer conductor connected to one end of the second portion of the ground plane.

Abstract: An automobile antenna including an antenna element which receives both AM and FM broadcast bands and is mounted on a vehicle body and a feeder cable having one end thereof connected to a feeding point of the antenna element and the other end to a receiver set, the feeder cable being set so that its electrical length is an integral multiple of 1/2 the wavelength of the FM broadcast band.

Abstract: A vehicle antenna for AM/FM and MT waves including a first antenna element for MT waves vertically mounted on the vehicle roof and a second antenna element for AM/FM waves rotatably coupled to the top end of the first antenna element so that the second antenna element can be set at a desired angle relative to the roof of the vehicle. A trap element for blocking MT waves is installed near the lower end of the second antenna element.

Abstract: In order to provide a broad-band non-grounded type ultrashort-wave antenna which has sufficiently high sensitivity characteristics and broad-band VSWR characteristics even in an expanded frequency band, is able to use a small-diameter antenna element, is light in weight and simple in structure, and can be manufactured inexpensively, an antenna element parallel resonance part, that is formed by the inductance and distributed capacitance of the rod-form antenna element which has an electrical length close to lambda/2 or an integral multiple of lambda/2, and a metal member parallel resonance part, that is formed by the electrostatic capacitance between first and second metal members which are installed parallel to each other and have respective electrical lengths of lambda/4 and the inductance of the first metal member, are electrostatically coupled by the stray capacity that exists between the antenna element and an electrostatic coupling piece projected from the second metal member, thus forming a double-tuned

Abstract: A tri-band antenna including an center conducting an inner pipe surrounding the center conductor, an outer pipe surrounding the inner pipe and Teflon provided between the inner and outer pipes.

Abstract: A shortened non-grounded type ultrashort antenna including an antenna element, an electrostatic coupling element electrostatically coupled to the antenna element, a rectangular first metal member with one end thereof connected to the electrostatic coupling element and an other end thereof extending in a direction perpendicular to the axis of the antenna element, a second rectangular metal member provided underneath and in parallel and spaced apart from the first metal member and having one end thereof connected to the extending end of the first metal member and a feeder line connected to the first and second metal members.

Abstract: A three-wave vehicle antenna in which an insulating pipe is connected to the tip of a conducting pipe, and an MT wave antenna element and a coaxial MT wave matching device are housed in the insulating pipe. One end of the coaxial MT wave feeder cable is connected to the matching device and the other end is guided through the conductive pipe which is designed to be used as an AM/FM antenna. The coaxial MT wave feeder cable uses polytetrafluoroethylene, at least for the external insulation member, for covering the outer conductor. With this arrangement it is possible for the three-wave vehicle antenna to check decreases in sensitivity of the AM/FM wave antenna element, since it is feasible to lower the stray capacity between the conductive pipe and the outer conductor of the coaxial MT wave feeder cable without enlarging the diameter of the conductor pipe.