Patents Assigned to The Antenna Company
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Patent number: 7292199Abstract: A radiator includes two radiating elements having a shape symmetrical with respect to an axis, and a transmission line portion connecting the tip end portions of these two radiating elements to each other. The radiating element has at least part of outer shape formed such that its distance from the axis increases with increasing distance from a midpoint of a line segment joining feed points to each other along the axis. Two radiator having such a shape are arranged along the receiving direction of electric waves and are fed with a phase difference, thereby realizing a miniaturized high-performance antenna apparatus.Type: GrantFiled: April 13, 2006Date of Patent: November 6, 2007Assignee: Dx Antenna Company LimitedInventor: Shotaro Horii
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Patent number: 7277063Abstract: Folded dipole antenna elements (2, 4) are disposed generally in parallel, being spaced by a distance smaller than a half of the wavelength employed. The antenna elements (2, 4) are connected to a combiner (16) via feeders (12, 14) having different lengths. The difference in length between the feeders (12, 14) is such that received signals resulting from a radio wave coming to the antenna elements (2, 4) from the front and received by the antenna elements (12, 14) are in phase with each other at the inputs (16a, 16b) of the combiner (16), whereas received signals resulting from a radio wave coming to the antenna elements (2, 4) from the back and received by the antenna elements (12, 14) are 180° out of phase with each other at the inputs (16a, 16b) of the combiner (16).Type: GrantFiled: April 1, 2004Date of Patent: October 2, 2007Assignee: DX Antenna Company, LimitedInventors: Toshiaki Shirosaka, Shingo Fujisawa, Toshio Fujita, Kiyotaka Tatekawa, Eiji Shibuya
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Patent number: 7205955Abstract: A transmission line includes transmission lines parallel and perpendicular, respectively, to a flat portion of a reflector, and the parallel transmission line and the flat portion form a first strip line and the perpendicular transmission line and a conductive plate similarly form a second strip line. Radiators and the transmission line have a radiation impedance and a characteristic impedance, respectively, both set at 150? when the antenna's output terminal has a reference impedance of 75?. If the parallel transmission line has a midpoint serving as the output terminal of the antenna this portion's receiving current is divided in two so that an impedance of half that of the strip line can be provided and a coaxial cable can directly be connected to the transmission line. A matcher or a mixer is not included in the antenna, and matching and mixing losses can be prevented.Type: GrantFiled: September 30, 2005Date of Patent: April 17, 2007Assignee: DX Antenna Company, LimitedInventors: Toshiaki Shirosaka, Shingo Fujisawa
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Patent number: 7205951Abstract: A multibeam primary radiator apparatus (2) includes first, second and third primary horns (16, 18, 20). The first primary horn (16) has a generally circular proximal end aperture (22) at its proximal end, and a generally circular distal end aperture (24) at its distal end, which is larger than the proximal end aperture (22). The second and third primary horns (18, 20) have generally circular proximal end apertures (26, 28) at their proximal ends, and larger distal end apertures (30, 32) at their distal ends. The first through third primary horns are disposed with the center axes of the respective proximal end apertures being substantially in parallel with each other. The distance between the center axis of the first primary horn (16) and each of the second and third primary horns (18, 20) is smaller than the diameter of the proximal end aperture (22) of the first primary horn (16).Type: GrantFiled: May 4, 2006Date of Patent: April 17, 2007Assignee: DX Antenna Company, LimitedInventor: Yoshikazu Matsui
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Patent number: 7084829Abstract: A signal receiving system includes a variable directivity antenna having its directivity varied in accordance with a control signal applied thereto. A control signal generator generating the control signal is provided in a receiving apparatus. The receiving apparatus includes also a modulator operating to ASK (amplitude-shift-keying) modulate a carrier with the control signal from the control signal generator into an ASK modulated signal. The ASK modulated signal is applied through a transmission line to the variable directivity antenna, and a controller associated with the variable directivity antenna demodulates the ASK modulated signal to recover the control signal for use in varying the directivity of the variable directivity antenna.Type: GrantFiled: March 9, 2004Date of Patent: August 1, 2006Assignee: DX Antenna Company, LimitedInventors: Toshiaki Shirosaka, Toshio Fujita, Kiyotaka Tatekawa, Shingo Fujisawa
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Patent number: 7071891Abstract: First, second, third and fourth dipole antennas (14, 16, 18, 20) are disposed in a casing (1). The first through fourth dipole antennas are arranged in the same plane, and are disposed in line symmetry with respect to first through fourth imaginary lines (A, B, C, D) passing through the center of the casing (1) at an angle of 45 degrees between adjacent imaginary lines.Type: GrantFiled: March 10, 2005Date of Patent: July 4, 2006Assignee: DX Antenna Company, LimitedInventors: Toshiaki Shirosaka, Kiyotaka Tatekawa, Toshio Fujita
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Patent number: 6965353Abstract: A multiple frequency band antenna includes a dipole antenna (4a), which is formed of two dipole antenna elements (8a, 10a). Two extension elements (24a, 26a) extend outward from respective ones of opposed outer ends of the dipole antenna (4a). The length of the dipole antenna (4a) is determined to make the multiple frequency band antenna capable of receiving radio waves in the UHF band, and the sum of the lengths of the dipole antenna (4a) and the extension elements (24a, 26a) is determined to make the multiple frequency band antenna capable of receiving radio waves in the VHF band. PIN diodes (28a, 34a) are connected between the respective extension elements (24a, 26a) and the respective outer ends of the dipole antenna (4a).Type: GrantFiled: April 12, 2004Date of Patent: November 15, 2005Assignee: DX Antenna Company, LimitedInventors: Toshiaki Shirosaka, Toshio Fujita, Kiyotaka Tatekawa, Shingo Fujisawa, Eiji Shibuya
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Patent number: 6933907Abstract: Folded dipole antenna elements (2, 4) are disposed generally in parallel, being spaced by a distance smaller than a quarter of the wavelength employed. The antenna elements (2, 4) are connected to a combiner (16) via feeders (12, 14) having different lengths. The difference in length between the feeders (12, 14) is such that received signals resulting from a radio wave coming to the antenna elements (2, 4) from the front and received by the antenna elements (12, 14) are in phase with each other at the inputs (16a, 16b) of the combiner (16), whereas received signals resulting from a radio wave coming to the antenna elements (2, 4) from the back and received by the antenna elements (12, 14) are 180° out of phase with each other at the inputs (16a, 16b) of the combiner (16).Type: GrantFiled: January 13, 2004Date of Patent: August 23, 2005Assignee: DX Antenna Company, LimitedInventors: Toshiaki Shirosaka, Shingo Fujisawa
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Patent number: 6914558Abstract: An antenna device (2a) includes first and second dipole antennas (4a, 6a) spaced from each other by a distance smaller than a quarter of a received wavelength. An antenna device (2b) includes third and fourth dipole antennas (4a, 6a) spaced from each other by the distance and is disposed orthogonal to the antenna device (2a). A first phase adjusting circuit (104a) combines signals from the first and second antennas (4a, 6a) after adjusting their phases, in such a manner that the resultant combined signal selectively assumes a forward directivity state exhibiting a forward directivity and a backward directivity state exhibiting a backward directivity. Similarly, a second phase adjusting circuit (104b) combines signals from the third and fourth antennas (4b, 6b) after adjusting their phases, in such a manner that the resultant combined signal selectively assumes a rightward directivity state exhibiting a rightward directivity and a leftward directivity state exhibiting a leftward directivity.Type: GrantFiled: October 29, 2004Date of Patent: July 5, 2005Assignee: DX Antenna Company, LimitedInventors: Toshiaki Shirosaka, Toshio Fujita, Kiyotaka Tatekawa, Eiji Shibuya
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Patent number: 6864855Abstract: A bracket (12) is fixed to the rear surface of a reflector (2). The bracket has a planar plate (14) which, when the bracket is fixed to the reflector, is perpendicular to a polarity axis (16). Plural, spaced-apart arcuate slots (20) arranged on an imaginary circle on the planar plate (14) about the polarity axis (16) are formed in the planar plate (14). An adapter plate (24) is disposed in contact with the surface of the planar plate (14) facing the reflector (2). The bracket (12) is rotatable about the polarity axis (16) relative to the adapter plate (24). The adapter plate (24) has screw holes (26) in alignment with the arcuate slots (20) in the planar plate (14). A bracket (28) is disposed on the side of the planar plate (14) opposite to the reflector (2). The bracket (28) has a pair of wings (30, 32). A connecting member (34) is formed integral with the wings (30, 32). The connecting member (34) is perpendicular to the wings (30, 32).Type: GrantFiled: October 14, 2003Date of Patent: March 8, 2005Assignee: DX Antenna Company, LimitedInventor: Kenichi Fujita
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Patent number: 6859182Abstract: An antenna system includes a VHF dipole antenna having a pair of rod elements disposed substantially in a line, and a UHF Yagi antenna having a radiator and a director disposed on the rod elements.Type: GrantFiled: October 22, 2002Date of Patent: February 22, 2005Assignee: DX Antenna Company, LimitedInventor: Shotaro Horii
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Patent number: 6774863Abstract: Antennas (8a-8d) are disposed within an antenna body (2) of an antenna system in such a manner as to receive UHF band radio waves coming to the main body (2) from a plurality of first, different directions around the main body (2). Combinations of the antennas (8a-8d) makes the antenna system possible to receive UHF band radio waves coming to the main body (2) from a plurality of second, different directions between adjacent ones of the first directions. Switches (26a-26d) disposed within the main body (2) select one of outputs provided by the individual antennas (8a-8d) and their combinations. An antenna controller (64a), a unit separate from the main body (2), supplies a selection control signal to the switches (26a-26d).Type: GrantFiled: February 3, 2003Date of Patent: August 10, 2004Assignee: DX Antenna Company, LimitedInventors: Toshiaki Shirosaka, Kiyotaka Tatekawa, Eiji Shibuya, Shingo Fujisawa, Shotaro Horii
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Patent number: D500753Type: GrantFiled: March 1, 2004Date of Patent: January 11, 2005Assignee: DX Antenna Company, LimitedInventor: Akihiko Nagatomi
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Patent number: D520499Type: GrantFiled: July 2, 2004Date of Patent: May 9, 2006Assignee: DX Antenna Company, LimitedInventor: Akihiko Nagatomi
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Patent number: D533545Type: GrantFiled: September 29, 2005Date of Patent: December 12, 2006Assignee: DX Antenna Company, LimitedInventor: Shigemi Inoue
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Patent number: D535982Type: GrantFiled: September 29, 2005Date of Patent: January 30, 2007Assignee: DX Antenna Company, LimitedInventor: Shigemi Inoue
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Patent number: D468302Type: GrantFiled: December 28, 2001Date of Patent: January 7, 2003Assignee: DX Antenna Company, LimitedInventor: Fusao Sato
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Patent number: D548730Type: GrantFiled: October 20, 2006Date of Patent: August 14, 2007Assignee: Dx Antenna Company, LimitedInventor: Shigemi Inoue
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Patent number: D558189Type: GrantFiled: December 12, 2006Date of Patent: December 25, 2007Assignee: DX Antenna Company, LimitedInventor: Shigemi Inoue
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Patent number: D489712Type: GrantFiled: March 3, 2003Date of Patent: May 11, 2004Assignee: DX Antenna Company, LimitedInventor: Akihiko Nagatomi