Abstract: Provided is a dual-polarization high-isolation Cassegrain antenna, including a main reflector, a secondary reflector and a diagonal horn feed. The diagonal horn feed includes an integrated cross-polarization coupling-structure and a diagonal horn protruding structure, where a hollow part of the diagonal horn protruding structure is diagonal horn-shaped, and a horn opening is upward. An edge line is arranged in the diagonal horn feed, and the edge line passes through the diagonal horn protruding structure and the cross-polarization coupling-structure. The cross-polarization coupling-structure includes a first port and a second port. The second port is located at a side surface of the diagonal horn feed, and an access is communicated with an edge line of a diagonal horn. The first port is located at a bottom surface of the diagonal horn feed.

Abstract: The underwater acoustic test system comprises an underwater acoustic transmitting unit, an underwater acoustic parabolic reflector, an underwater acoustic receiving unit, an orientation control system, and a computer measurement and control system. The underwater acoustic transmitting unit comprises an underwater acoustic signal generator and a transmitting transducer. The underwater acoustic parabolic reflector comprises a central main reflecting area and an edge diffraction processing area, wherein the central main reflecting area is configured for reflecting acoustic wave signals, and the edge diffraction processing area is configured for reducing the influence of the underwater acoustic parabolic reflector on a test area. The underwater acoustic receiving unit comprises a receiving transducer and an underwater acoustic signal receiver. The orientation control system comprises a traveling crane and a test turntable.

Abstract: The underwater acoustic test system comprises an underwater acoustic transmitting unit, an underwater acoustic parabolic reflector, an underwater acoustic receiving unit, an orientation control system, and a computer measurement and control system. The underwater acoustic transmitting unit comprises an underwater acoustic signal generator and a transmitting transducer. The underwater acoustic parabolic reflector comprises a central main reflecting area and an edge diffraction processing area, wherein the central main reflecting area is configured for reflecting acoustic wave signals, and the edge diffraction processing area is configured for reducing the influence of the underwater acoustic parabolic reflector on a test area. The underwater acoustic receiving unit comprises a receiving transducer and an underwater acoustic signal receiver. The orientation control system comprises a traveling crane and a test turntable.

Abstract: Provided is a wide band antenna having ultra-wide band and high performance at a low cost. An antenna element constituting a part of an opening cross section structure of a double cylinder ridge waveguide is spread on a plane. The antenna element has a ridge element portion (21) for adjusting antenna characteristic corresponding to a ridge portion and a radiation element portion (22) for electromagnetic wave radiation. Substantially at a leading end portion of the ridge element portion (21), a feeder terminal (24) is formed. Ground portions (23a and 23b) are maintained at a ground potential and the feeder terminal (24) is guided to an outside as a coplanar waveguide.

Abstract: To provide a smaller radar system having a simple structure with as small number of component parts as possible at a lower cost as compared to conventional ones. A radar system 1 including a 3 dB coupler 5 having four terminals, and a pulse generator 8. A first terminal 51 of the 3 dB coupler 5 is supplied with an output signal from a high frequency oscillator 2 while a second terminal 52 of the 3 dB coupler 5 is connected to a transmitting and receiving antenna 4. Third and fourth terminals 53 and 54 of the 3 dB coupler 5 are connected to two-state devices 6, 7, respectively, which are in impedance mismatched only for a predetermined period of time to totally reflect the signal from the 3 dB coupler 5 and are in impedance matched during the time period other than the predetermined time to direct a signal from the 3 dB coupler 5 to a subsequent electronic circuit.

Abstract: There is provided a low-cost wide band antenna having an ultra-wide band and high performance. The wide band antenna includes an antenna element to form a shape of a ridge waveguide open cross-section structure together with GND (10) when it is spread. The antenna element has a ridge element portion (13) corresponding to the ridge portion of the ridge waveguide and a radiation element portion (14) corresponding to the wall of the ridge waveguide and extending from the ridge element portion (13) for electromagnetic wave radiation. Moreover, the antenna element has an opposing auxiliary element (12) having the same shape and structure as the ridge element portion (13). The radiation element portion (14) has an end arranged on the GND (10). The ridge element portion (13) has a tip end connected to a power supply terminal (100).

Abstract: Provided is a wide band antenna having ultra-wide band and high performance at a low cost. An antenna element constituting a part of an opening cross section structure of a double cylinder ridge waveguide is spread on a plane. The antenna element has a ridge element portion (21) for adjusting antenna characteristic corresponding to a ridge portion and a radiation element portion (22) for electromagnetic wave radiation. Substantially at a leading end portion of the ridge element portion (21), a feeder terminal (24) is formed. Ground portions (23a and 23b) are maintained at a ground potential and the feeder terminal (24) is guided to an outside as a coplanar waveguide.

Abstract: To provide a smaller radar system having a simple structure with as small number of component parts as possible at a lower cost as compared to conventional ones. A radar system 1 including a 3 dB coupler 5 having four terminals, and a pulse generator 8. A first terminal 51 of the 3 dB coupler 5 is supplied with an output signal from a high frequency oscillator 2 while a second terminal 52 of the 3 dB coupler 5 is connected to a transmitting and receiving antenna 4. Third and fourth terminals 53 and 54 of the 3 dB coupler 5 are connected to two-state devices 6, 7, respectively, which are in impedance mismatched only for a predetermined period of time to totally reflect the signal from the 3 dB coupler 5 and are in impedance matched during the time period other than the predetermined time to direct a signal from the 3 dB coupler 5 to a subsequent electronic circuit.

Abstract: An antenna element 1 is formed such that a plurality of turning parts 13, 15, 17 are formed by being turned back in zigzag in parallel to a ground conductor film 2 while extending perpendicularly thereto and the lengths of segments 12, 14, 16, 18 between the turning parts are shorter on a side of the ground conductor film 2 (a side of a feeding part 4) and increase gradually as the segments are away from the ground conductor film 2. The turning parts of the antenna element 1 are formed such that the antenna resonates at two or more frequency bands, and has a fractional bandwidth of 4% or more of its frequency in a first frequency band and a fractional bandwidth of 15% or more of its frequency in a second frequency band by adjusting the lengths L1, L2 and L3 of respective segments and the intervals d1, d2 and d3 between adjacent segments. Consequently, a wideband antenna is realized in two or more multi-frequency bands, for example 2.4 to 2.5 GHz and 5 to 6 GHz, by using a single folded antenna.

Abstract: There is provided a low-cost wide band antenna having an ultra-wide band and high performance. The wide band antenna includes an antenna element to form a shape of a ridge waveguide open cross-section structure together with GND (10) when it is spread. The antenna element has a ridge element portion (13) corresponding to the ridge portion of the ridge waveguide and a radiation element portion (14) corresponding to the wall of the ridge waveguide and extending from the ridge element portion (13) for electromagnetic wave radiation. Moreover, the antenna element has an opposing auxiliary element (12) having the same shape and structure as the ridge element portion (13). The radiation element portion (14) has an end arranged on the GND (10). The ridge element portion (13) has a tip end connected to a power supply terminal (100).

Abstract: An antenna element 1 is formed such that a plurality of turning parts 13, 15, 17 are formed by being turned back in zigzag in parallel to a ground conductor film 2 while extending perpendicularly thereto and the lengths of segments 12, 14, 16, 18 between the turning parts are shorter on a side of the ground conductor film 2 (a side of a feeding part 4) and increase gradually as the segments are away from the ground conductor film 2. The turning parts of the antenna element 1 are formed such that the antenna resonates at two or more frequency bands, and has a fractional bandwidth of 4% or more of its frequency in a first frequency band and a fractional bandwidth of 15% or more of its frequency in a second frequency band by adjusting the lengths L1, L2 and L3 of respective segments and the intervals d1, d2 and d3 between adjacent segments. Consequently, a wideband antenna is realized in two or more multi-frequency bands, for example 2.4 to 2.5 GHz and 5 to 6 GHz, by using a single folded antenna.

Abstract: A laminated dielectric block (3) is formed by laminating dielectric sheets (31) each having a conductive film formed on its one surface so as to constitute at least one filter (2). A radiation element (1) is provided so as to fix to the laminating dielectric block, wherein one electrode of the filter is electrically connected to the radiation element. The other electrode (22) of the filter is connected to a feeding terminal electrode (4) provided mounting face B (a face opposing to a circuit board) of the laminated dielectric block through a via-contact (33) and a wiring (34), not being exposed to the side face. As a result, an antenna with built-in filter of the structure where even if it is mounted on a circuit board, interference between an electronic circuit on the circuit board and the feeding terminal electrode of the antenna is prevented to improve the isolation characteristic and transmitting or receiving characteristic.

Abstract: A ground conductor plane 1 and an excitation electrode 2 are provided substantially in parallel with each other. Two electrodes 3a and 3b for respectively radiating a linearly-polarized wave are provided substantially in parallel with the ground conductor plane 1, with the excitation electrode 2 interposed therebetween. The radiation electrodes are provides in close proximity to the excitation electrode 2 such that one end of each of the radiation electrodes 3a and 3b establishes capacitive coupling with respect to the excitation electrode 2. The other ends of each of the radiation electrodes 3a and 3b are grounded such that the directions in which electric fields are to be excited becomes substantially orthogonal to each other. For instance, a feeding section 4 is provided in flush with the ground conductor plane 1 and is electrically connected to the excitation electrode 2 via a feeding electrode 5.