Abstract: A multibeam antenna apparatus is disclosed. The multibeam antenna apparatus includes a main reflector (1), a sub-reflector (2), a focused beam feeder (3), a primary radiator array (5) having a plurality of primary radiators (5a), and a lens array (10) having a plurality of wavefront transformation lenses (10a) corresponding to the plurality of primary radiators (5a), respectively. The lens array (10) can be placed in the vicinity of a front end of the primary radiator array (5). As an alternative, the lens array (10) is placed in an electric wave propagation range of the focused beam feeder (3) where multiple beams which constitute a multibeam are spatially isolated from one another in terms of electric power. Thus the multibeam antenna apparatus can prevent an error from occurring in the orientation of each beam.

Abstract: A multibeam antenna apparatus is disclosed. The multibeam antenna apparatus includes a main reflector (1), a sub-reflector (2), a focused beam feeder (3), a primary radiator array (5) having a plurality of primary radiators (5a), and a lens array (10) having a plurality of wavefront transformation lenses (10a) corresponding to the plurality of primary radiators (5a), respectively. The lens array (10) can be placed in the vicinity of a front end of the primary radiator array (5). As an alternative, the lens array (10) is placed in an electric wave propagation range of the focused beam feeder (3) where multiple beams which constitute a multibeam are spatially isolated from one another in terms of electric power. Thus the multibeam antenna apparatus can prevent an error from occurring in the orientation of each beam.

Abstract: In a horn antenna apparatus for use in an antenna system for radar, some of the excited radio waves in a TE11 mode in a radio-wave input portion 1 are converted to those in a higher mode in a waveguide portion 5. As the inclination of a line of intersection S of the waveguide portion 5 is not fixed but continuously varied, the higher mode such as a TM11 mode and TE12 mode and the like is excited everywhere in the direction of the axis Z of the waveguide portion 5. Then the configuration of the line of intersection is determined so that an amplitude and a phase as the generated quantity of higher mode such as the TM11 mode generated in the waveguide portion 5 conform to desired values with respect to each higher mode.

Abstract: In a horn antenna apparatus for use in an antenna system for radar, some of the excited radio waves in a TE11 mode in a radio-wave input portion 1 are converted to those in a higher mode in a waveguide portion 5. As the inclination of a line of intersection S of the waveguide portion 5 is not fixed but continuously varied, the higher mode such as a TM11 mode and TE12 mode and the like is excited everywhere in the direction of the axis Z of the waveguide portion 5. Then the configuration of the line of intersection is determined so that an amplitude and a phase as the generated quantity of higher mode such as the TM11 mode generated in the waveguide portion 5 conform to desired values with respect to each higher mode.

Abstract: In order to receive simultaneously signals with different polarizations, the antenna feeding system is adapted to comprise diplexers and a hybrid circuit for synthesizing signals, which are transmitted through signal paths allocated to the frequency of a circularly polarized wave from the diplexers, upon giving 90° phase difference therebetween and for selectively outputting the synthesized signal to either one of signal terminal for right handed circularly polarized wave or for left handed circularly polarized wave.

Abstract: An antenna mirror surface measuring/adjusting apparatus has a plane mirror larger than an aperture surface of said principal reflection mirror and set in parallel with the aperture surface, an actuator for driving a group of mirror surface panels of the principal reflection mirror, and a receiving electric field arithmetic processor for measuring, each time the actuator shifts a position of the mirror surface panel from an initial state of the mirror surface panel of the principal reflection mirror, radio wave signals of radio waves radiated by a transmitter/receiver and reflected back from the plane mirror, obtaining an aperture surface phase distribution in an initial state of the principal reflection mirror by executing an arithmetic process on these measured signals, then gaining configurations of the mirror surface on the basis of the aperture surface phase distribution, and adjusting the mirror surface by the actuator in accordance with the obtained mirror surface configurations.

Abstract: A phase measurement circuit of a phased array antenna having both transmitting and receiving functions includes a plurality of antenna elements arranged in a line or on a plain; phase shifters disposed corresponding to the antenna elements, respectively, for shifting phases of signals to form a beam in a desired direction by changing the phase value; a control circuit for controlling the phase shift quantity of the phase shifter; a test antenna for receiving electric wave of a transmission frequency band from the phased array antenna and transmitting a test signal for measuring an excitation phase to each element of the phased array antenna; and a test translator for converting a frequency of the signal of the transmission frequency band received by the test antenna to that of the signal of a reception frequency band and outputting it as a test signal to the test antenna.

Abstract: In an electronic scanning type array antenna device according to the present invention, the circuit is constituted to be able to select a case in which any one antenna unit out of a plurality of electronic scanning type array antenna units is operated to form a radiation pattern, or a case in which any two or more, including all, antenna units out of the plurality of electronic scanning type array antenna units are operated to form a radiation pattern; thereby a radio beam can be scanned in a desired direction in a wide range with a smaller number of antenna elements and phase shifters in comparison with that of a conventional device.