Abstract: In a method of designing the transmission power of a synthetic aperture radar installed on a flight object such as an artificial satellite, the transmission power is designed such that, in applying radar equation P.sub.r =P.sub.t .multidot..sigma..multidot.A.sub.p.sup.2 /(4.pi..lambda..sup.2 R.sup.4) [P.sub.t :transmission power (W), .sigma.: radar scattering cross section (m.sup.2), A.sub.p :antenna area (m.sup.2), R: distance to the object to be observed (m), .lambda.: wavelength of radio wave (m)] for setting transmission power P.sub.r so as to satisfy the conditions required for the radar, the radar scattering cross section .sigma. is set to .sigma.=.sigma..sup.0 .multidot.S.sup.2 .multidot.4.pi./ .lambda..sup.2 [.sigma..sup.0 :scattering coefficient, S:area of irradiated domain (m.sup.2)].

Abstract: An active reflector including an antenna, a frequency converter, and a delay circuit is placed at a location within an area to be detected by a synthetic aperture radar. The active reflector receives an incoming radio wave emitted by the synthetic aperture radar and changes its frequency or delay time. The resultant radio wave is transmitted as a reflected radio wave toward the synthetic aperture radar. As a result, the position of the active reflector image displayed on the screen of the synthetic aperture radar is shifted. The ambiguity is quantitatively detected from the pixel value at the original display position at which the active reflector image was displayed before it was shifted, thereby evaluating the image quality of the synthetic aperture radar.

Abstract: An antenna system comprising two similar antennas with a monopulse feed system is scanned while transmitting in-phase radio waves from the two antennas. Reflected radio waves are received by the two antennas and fed to a hybrid circuit which in turn produces a sum signal .SIGMA. and a difference signal .increment.. After detection is performed by a detector, a signal processing unit performs double differential processing on the sum signal .SIGMA. and the differential signal .increment.. In this processing step, the sum signal is output only if the double differential coefficient of said sum signal is equal to or less than a predefined positive real number value and if the double differential coefficient of said difference signal is equal to or greater than a predefined negative real number value, and a zero signal is output in any other cases. Thus, the beam width of an antenna pattern is compressed without missing a necessary output signal.

Abstract: A seed crystal is connected with a polycrystal at one end of the polycrystal, the connected crystal material is melted under a zero-gravity or microgravity environment without any container, and a single crystal is grown.

Abstract: An antenna system is formed by arranging a sub-antenna adjacent to a main antenna along the direction of the beam width to be reduced of the main antenna and in such a way that the beam axis of the sub-antenna is coincident with that of the main antenna. The antenna beam of this antenna system is scanned along the beam width direction and received signals obtained by the main and sub-antennas are set in phase and subjected to multiplication and signal processing by a multiplication circuit and signal processing circuit.

Abstract: An antenna system comprising two similar radiation antenna elements with a single monopulse feed system is scanned while transmitting in-phase radio waves from the two elements. Reflected radio waves are received by the two elements and fed to a hybrid circuit which in turn produces a sum signal .SIGMA. and a difference signal .DELTA.. After detection is performed by a detector, a signal processing unit subtracts the difference signal .DELTA. from the sum signal .SIGMA.. In this processing step, the output signal produced by the above subtraction process is actually output only if the receiving pattern waveform associated with the sum signal .SIGMA. has an upwardly convex form, that is, its double differential coefficient is negative and further if the receiving pattern waveform associated with the difference signal .DELTA. has a downwardly convex form, that is, its double differential coefficient is positive, whereby an antenna pattern with beam compression is provided.

Abstract: An array antenna mounted on a spacecraft in its stowed state. After the spacecraft is launched in a predetermined position or on a predetermined orbit, the array antenna is extended to a flat plate form or a curved surface form. The array antenna has a structure that a plurality of subarrays are connected by plate springs or the like. The array antenna is extended in a kite form by using cables for connecting a spacecraft body and the subarrays or is extended by using an extension pole mounted on the spacecraft body. Each subarray includes a variable phase shifter to switch a shape and a direction of a directivity beam. A feeder line, a power supply line, a control signal line and the like connect the spacecraft body and each subarray.

Abstract: Crystal growing cell including first and second casings. The first casing has a first solution chamber for containing a first solution therein. The first solution chamber has an opening. The second casing has a closing member placed therein for movement in a first direction and in a second direction opposite to the first direction. The second casing has a third casing placed therein. The third casing is fixed to the first casing around the opening to form a second solution chamber for containing a second solution therein. The closing member is moved in the first direction to close the opening so as to separate the first solution chamber from the second solution chamber. The closing member is moved in the second direction to open the opening so as to connect the first solution chamber to the second solution chamber.

Abstract: An antenna system comprises a main antenna for use of transmission and reception and a dedicated sub-antenna for use of reception. The antenna beam of the antenna system is scanned in the direction of a beam width to be compressed. Both received signals of the main antenna and the sub-antenna are fed to a signal processing circuit and a multiplying circuit, and converted to power signals and then multiplied each other. In this processing, only if the cosine value corresponding to the phase difference between the received power signals of the main antenna and the sub-antenna is positive, the multiplication between the received power signals is carried out and the result is further multiplied by the cosine value, and then the obtained signal is output as a final output signal.

Abstract: An antenna system comprises a main antenna for use of transmission and reception and a pair of sub-antennas use of only reception. The antenna beam of the system is scanned in the direction of a beam width to be compressed. Both received signals of the main antenna and the sub-antennas are fed to a signal processing circuit. The signal processing circuit converts these received signals to power signals and then performs signal processing on them. In this signal processing, the power signal received by the main antenna is output as a final output signal only if both double differential coefficients of the received signals received by the main antenna and the sub-antennas are equal to or less than corresponding predefined positive real number values, and if the phase difference between the power signal received by the main antenna and the power signal received by the sub-antennas is equal to or less than 90.degree.

Abstract: There is disclosed an antenna device having low side-lobe characteristics comprising a pair of array antennas having the same construction. Each array antenna has array elements equidistantly arranged. The center-to-center distance between the array antennas is so determined that the angle of the first zero point of the array factor determined by the center-to-center distance equals the angle of the first side lobe point of the pattern of each array antenna. The array antennas are electrically connected so as to become excited in phase.

Abstract: An antenna system including a sub antenna adjacent a main antenna in the direction where a beam width of the main antenna is to be compressed and a beam axis of the sub antenna is coincident with a beam axis of the main antenna. Antenna beams of the antenna system are scanned in the direction of compression of the beam width. Received signals of the main antenna and the sub antenna are subjected to a step of signal processing and multiplication process in a signal processing and multiplying circuit. In that step, only when the received pattern waveform of the main antenna and the received pattern waveform of the sub antenna are both at local maximum levels, the received signal of the sub antenna is output and subjected to the multiplication process for preventing the occurrence of distortion in the received pattern.

Abstract: A monopulse tracking apparatus comprises first to fourth electromagnetic horns disposed symmetrically to each other in an azimuthal direction and elevation direction in a 2.times.2 matrix state, a first hybrid circuit for creating the sum signal and difference signal of the first and second electromagnetic horns, a second hybrid circuit for creating the sum signal and difference signal of the third and fourth electromagnetic horns, a third hybrid circuit supplied with the respective sum signals of the first and second hybrid circuits and for outputting the sum signal and difference signal thereof, a fourth hybrid circuit supplied with the respective difference signals of the first and second hybrid circuits and outputting the sum signal and difference signal thereof, and a fifth hybrid circuit for creating the sum signal and difference signal of the first and fourth electromagnetic horns or the second and third electromagnetic horns.

Abstract: After each received signal in the same two antennas of the monopulse power feed system are inputted into a hybrid circuit, a sum signal .SIGMA. and a difference signal .DELTA. are formed, and they are demodulated in detection circuits, zero is outputted if the value of the sum signal .SIGMA. is equal to or smaller than the value of the difference signal .DELTA., otherwise the value subtracted the difference signal .DELTA. from the sum signal .SIGMA. outputted, in a signal processing section. Thus, beam compression and reduction of a side lobe are performed.

Abstract: A method for reducing side lobes wherein an antenna system comprises a main antenna and a sub antenna which does not have an isotropic antenna pattern in a direction (X direction) of an orientation of a side lobe of the main antenna to be reduced which is arranged in such a way that the sub antenna adjoins the main antenna in the direction (Y direction) perpendicular to the X direction and the beam axis of the sub antenna coincides with the beam axis of the main antenna; wherein an antenna beam of the antenna system is scanned in the X direction and a signal received with the main antenna is multiplied by a signal received with the sub antenna on the condition that phases of both signals coincide with each other.

Abstract: A method for processing an antenna pattern in which a first antenna system is placed to correspond with a first direction in relation to the beam width to be compressed, a second antenna system of the monopulse power feed system is placed to correspond with a second direction lying at a right angle to the first direction, in which an antenna beam of the first and the second antenna systems is scanned in a direction other than the first and the second directions. A sum signal .SIGMA.1, a difference signal .DELTA.1 and sum signal .SIGMA.2, difference signal .notident.2 are formed in hybrid circuits, and an output signal two-dimensionally compressed are obtained as a result of adding a signal resulting from the subtraction of the difference signal .DELTA.1 from the sum signal .SIGMA.1 to a signal resulting from the subtraction of the difference signal .DELTA.2 from the sum signal .SIGMA.2 in a signal processing section.

Abstract: A solid-state imaging device includes a plurality of light receiving elements, transfer gates for controlling reading-out of signal charges generated by the light receiving elements, a charge coupled device for transferring the signal charges from the light receiving elements through the transfer gates, a charge input electrode, and first and second electrodes for controlling the quantity of charges input from the charge input source. The first electrode contacts the charge input source. The second electrode contacts the first electrode and is connected to a light receiving element via a transfer gate or another charge coupled device. In this structure, the second electrode controls the quantity of input charges in response to a dc voltage in a charge input mode for testing the images and serves as a first stage transfer electrode in response to a clock pulse in a imaging mode for forming an image. Thus, the pitch of the light receiving elements is constant even at the charge input electrode.

Abstract: An antenna system comprises: a main antenna; a first sub antenna arranged in such a way that the first sub antenna adjoins the main antenna in the X direction which is the orientation of a beam width of the main antenna to be reduced and the beam axis of the first sub antenna coincides with the beam axis of the main antenna; and a second sub antenna arranged in such a way that the second sub antenna adjoins the main antenna in the Y direction perpendicular to the X direction and the beam axis of the second sub antenna coincides with the beam axis of the main antenna; wherein an antenna beam of the antenna system is scanned in a direction other than the X and Y direction and multiplication is carried out between a signal received with the main antenna and each signal received with each sub antenna on the condition that phases of these signals coincide with each other so that a two-dimensional reduction in a beam width is achieved.

Abstract: A ranging method for measuring the flight distance of a flight object is implemented by means of a simple system construction. The ranging method is also capable of continuing ranging even if an interruption occurs in data transmission. The ranging method comprises the steps of inserting ranging pulses in a telemeter signal transmitted from a transmitting apparatus provided on the flight object, separating and extracting a ranging pulse from a telemeter signal received by a receiving apparatus provided on the ground side, obtaining a time difference between the ranging pulse and a reference clock signal generated in the receiving apparatus on the basis of a time reference equal to that of the transmitting apparatus (clock signal periods t1 and t2 of both time references are equal), and calculating the flight distance.

Abstract: In a rendezvous maneuver for approaching a rendezvous spacecraft to a target spacecraft through a reference trajectory for approach which is different in altitude and period from a trajectory of the target spacecraft, when the rendezvous spacecraft is deviated from the reference trajectory for approach as a result from a failure in the maneuver, it is first maneuvered in the direction of altitude after 0.2 revolutions of the rendezvous spacecraft, and then maneuvered in the direction of phase after another 0.2 revolutions. The rendezvous spacecraft is thereby restored to the reference trajectory with no fear of entering a collision course, so that high reliable retry/recovery may be performed promptly and safely.