Michio Takikawa

One-dimensional beam scanning reflector antenna for small satellite applications

We propose a new compact center-fed reflector antenna with one-dimensional beam scanning function for small satellite application. The proposed antenna has different curves in orthogonal two cross sections. The beam scanning cross section is an imaging reflector form. The non-beam scanning cross section is an axial symmetry Cassegrain form. In this paper, we describe the design method of the proposed antenna based on a doubly curved reflector. The measurement of a prototype antenna demonstrates the validity of the proposed antenna.

Trade-off of multibeam reflector antenna configuration for satellite onboard application

Recently, demands on high throughput communication for airplanes and ships by high throughput satellite using Ka-band have been increased. Frequency and polarization reuse method with covering service area by multiple spot beams is widely adopted to increase frequency band efficiency. A configuration of reflector and multiple primary feeds is widely used for multi-beam antenna because of its high gain property and simple configuration. In this paper, two configurations, single feed per beam and multiple feed per beam, are compared by Ka-band 16 multibeam scenario.

Initial reflector design method for shaped reflector antennas using Laguerre-Gaussian beam modes

We propose an initial reflector design method for shaped-beam reflector antennas that uses the Laguerre-Gaussian beam modes. The feature of this design method is to design the phase distribution of the initial surface that covers the desired coverage area. By using the proposed design method, the non-linear optimization is expected to be reduced for shaped reflector antenna design. In this paper, the iteration number of the proposed design method will be discussed first. Then, the validity of the proposed design method for the shaped reflector antenna that covers the Japan area will be discussed as an example.

A novel disk type support structure installed in a quadrifilar helical antenna for satellite application

We propose a new type of support structure for helical antennas which are made of rolled cylindrical film resin substrate. The structure is composed of a rod arranged on the cylinder axis and disks fixed to it, which have a function that holds the cylindrical film, at specific intervals. This structure suppresses deterioration in antenna performances under adverse conditions of satellite application with vibrations. The configuration is found to be optimum in which the disks are arranged from the position that fell down from the helical upper end by 0.25 λg along the helical element. Here, λg is guide wavelength along the helical element.