Abstract: An antenna apparatus comprises a dielectric substrate, an earth conductor mounted on one surface of the substrate and forming a microstrip transmission line, an upper conductor mounted on the other surface of the substrate and forming a microstrip transmission line, an antenna element formed integrally with the microstrip transmission lines, and a delayed wave opening situated in the earth conductor in confronting relationship with the upper conductor.

Abstract: An array antenna system having a predetermined electric current distribution on an antenna aperture to form a desired shape of antenna beam. Active antenna elements arranged on the aperture transmit a signal for electronically scanning a predetermined region to detect a target and receive a signal reflected by the target. Passive antenna elements are also arranged on the aperture. The antenna system further includes a direction finding section including reception antenna elements which receive an incident signal. The active, passive and reception antenna elements are positioned to allow a predetermine electric current distribution to be established on the antenna aperture.

Abstract: A phased array antenna includes a plurality of first antenna elements and a plurality of phase shifters respectively connected to the first antenna elements. An amplitude and a phase of each of the antenna elements are determined by a method of opposing a pick-up antenna at a distance from the phased array antenna to measure a composite power of the phased array antenna while changing phases of the phase shifters for determining the ratio of the maximum power to the minimum power, and the phase value for the maximum power, from which the amplitude and phase are computed.

Abstract: A conformal array antenna system is disclosed comprising a structural base body having a shape suitable for a surface of an airplane or a ship, and a plurality of antenna units disposed on the structural base body. Signals received by these antenna units are converted into digital signals and fed to a digital beam forming circuit which synthesizes such digital signals to form a multiplicity of beams. The antenna units and the digital beam forming circuits may be connected by electrical transmission lines or optical fibers.

Abstract: A microstrip antenna offering a wide bandwidth while suppressing the standing wave ratio is obtained by interposing a conductor plate between a radiating conductor element and a ground plane conductor.

Abstract: Antenna device for detecting a direction of an object lying in a low angle direction, which is constructed with a plurality of antenna elements, feeds, and so forth, and comprises a central feed for feeding RF signals to one or a plurality of central antenna elements, and a peripheral feed for feeding RF signals to a plurality of peripheral antenna elements, and that one of input terminals of the central feed and one of input terminals of the peripheral feed are connected together by a hybrid circuit.