Abstract: The present invention aims at providing a circular waveguide polarizer with high performance and low cost. The circular waveguide polarizer is realized by arranging a plurality of side grooves 12 in a side wall of a circular waveguide 11 along the direction of a pipe axis C1 and by appropriately designing the number, spacing, radial depth, circumferential width, length in the pipe axis direction, and the like. According to this circular waveguide polarizer, disturbance is imparted to a section with a coarse electromagnetic field distribution in a transmission mode to create a phase delay, so that the amount of phase delay does not vary largely with a delicate change in width, depth and length of the side grooves 12. That is, there is little deterioration in characteristics caused by a machining error or the like, and hence it becomes possible to effect mass production and cost reductions.

Abstract: It is an object of the present invention to realize a low-pass filter that has an increased number of stages of filter elements and can obtain a large combined capacitance with a simple configuration of a plane circuit, can set an attenuation pole in the vicinity of a pass band and has a steep out-of band attenuation characteristic. In order to attain such an object, three or more top end open stubs, which are set to have a large electric length in a range in which a length of is shorter than ¼ of a wavelength of a pass frequency, are disposed substantially in parallel so that their respective open ends face an identical direction to thereby form a combined line, and a high impedance line that is shorter than the wavelength of the pass frequency is connected to at least one part among parts between neighboring ends on the opposite side of open ends of the top end open stubs.

Abstract: In order to provide a reflector antenna apparatus which can be installed within a small space, which has adequate practicality, and which can perform scanning by pivoting about two axes which are perpendicular to each other, in a reflector antenna apparatus having a Cassegrain reflector and a rotating mechanism which rotates the reflector about an azimuth axis and an elevation axis, a reflector with a substantially rectangular aperture has its elevation axis passing through substantially the central portion of the height dimension of the reflector, and reflector surface adjustment is carried out such that substantially all of the electromagnetic waves which are supplied are received and reflected, whereby the antenna height does not become large when the reflector rotates about the elevation axis. The reflector may be an array of a plurality of reflector elements.

Abstract: For the purpose of obtaining a mechanical drive reflecting mirror antenna device which is downsized and low in attitude, enables wide-angle scanning, and is high in performance, there are provided a main reflection mirror 1, a sub-reflection mirror 2, a primary radiator 3, a first circular waveguide 4 which is connected to the primary radiator and has a plurality of bend portions, a first circular waveguide rotary joint 5 which is connected to the first circular waveguide, a second circular waveguide 7 which is connected to the first circular waveguide rotary joint and has a plurality of bend portions, and a second circular waveguide rotary joint 8 which is connected to the second circular waveguide and is different in a direction of a rotary axis from the first circular waveguide rotary joint by substantially 90 degrees.

Abstract: The waveguide group branching filter according to the present invention is formed by boring out of two metal blocks constituent circuits including a circular-to-square waveguide multistage transformer 1, the branch waveguide polarizer/branching filter 4, a rectangular waveguide multistage transform 9, the rectangular waveguide H-plane T-branch circuit 10, and waveguide band-pass filters 8, 14 and 18; radio waves V1 and H1, which have their polarization planes vertical and horizontal, respectively, to the branching plane of the branch waveguide polarizer/branching filter 4 in a certain frequency band f1, and a radio wave V2 of the same polarization plane as that of the radio wave V1 in a frequency band f2 higher than the frequency band f1 are incident to an input port P1, and the radio wave V1 is emitted from an output port P2, the radio wave H1 from an output port P3 and the radio wave V2 from an output port P4.

Abstract: It is an object of the present invention to realize a low-pass filter that has an increased number of stages of filter elements and can obtain a large combined capacitance with a simple configuration of a plane circuit, can set an attenuation pole in the vicinity of a pass band and has a steep out-of band attenuation characteristic. In order to attain such an object, three or more top end open stubs, which are set to have a large electric length in a range in which a length of is shorter than ¼ of a wavelength of a pass frequency, are disposed substantially in parallel so that their respective open ends face an identical direction to thereby form a combined line, and a high impedance line that is shorter than the wavelength of the pass frequency is connected to at least one part among parts between neighboring ends on the opposite side of open ends of the top end open stubs.

Abstract: The present invention aims at providing a circular waveguide polarizer with high performance and low cost. The circular waveguide polarizer is realized by arranging a plurality of side grooves 12 in a side wall of a circular waveguide 11 along the direction of a pipe axis C1 and by appropriately designing the number, spacing, radial depth, circumferential width, length in the pipe axis direction, and the like. According to this circular waveguide polarizer, disturbance is imparted to a section with a coarse electromagnetic field distribution in a transmission mode to create a phase delay, so that the amount of phase delay does not vary largely with a delicate change in width, depth and length of the side grooves 12. That is, there is little deterioration in characteristics caused by a machining error or the like, and hence it becomes possible to effect mass production and cost reductions.

Abstract: A high frequency filter includes a dielectric plate 8, an outer conductor 9 formed on the one surface of the dielectric plate 8, a plurality of strip conductors 10a-10d formed approximately in parallel on the other surface of the dielectric plate 8, a strip conductor 15 formed in a direction crossing the strip conductors 10a-10d, short-circuiting portions 11 and 16 connecting the one ends of the strip conductors 10a-10d and the strip conductor to the outer conductor 9, respectively, and further comprises a plurality of resonators 110a-110d constructed by the strip conductors 10, a plurality of capacitors (gaps) 12 coupling the resonators to each other to be connected in series, capacitors 13 connecting the strip conductors 10a, 10d to an input terminal and an outer conductor, respectively, a resonator 200 constructed by the strip conductor 15, and a plurality of capacitors (gaps) 33 connecting the strip conductors 10a, 10d to the resonator 200.