Toshiro Hiratsuka

A Ka-Band Diplexer Using Planar TE Mode Dielectric Resonators with Plastic Package

A Ka-band diplexer using novel planar nar TE mode dielectric resonators has been developed. The resonators are manufactured with precise photolithography process on the high-dielectric-constant ceramic substrate. High unloaded-Q of 1100 is obtained at 26-27 GHz. A small-size diplexer with low loss and high attenuation characteristics is realized. This diplexer has been made within a plastic package which shows excellent thermal stability. The diplexer can be applicable to widely-expanding high-speed subscriber radio communication systems.

A Ku-band transversal filter using directional Couplers made of a multilayer ceramic

A Ku-band transversal filter using directional couplers has been developed. Calculations confirm that the increase in insertion loss due to a decreasing Q-factor is much less than that for a resonator filter. The filter is accurately designed by using three-dimensional electro-magnetic field analysis, and is made of a multilayer ceramic to obtain high homogeneity. Measured transmission characteristics agree well with calculated values. Such a filter type is believed to be more suitable for MICs and MMICs than a resonator filter because of low insertion loss.

A Ka-Band Bandpass Filter Using Open-End Planar TE Mode Dielectric Resonators with Cross-Coupling Structure

A novel planar-type dielectric resonator filter and a diplexer were developed. Open-end planar TE mode dielectric resonators are adopted for I/O interface to reduce the insertion loss of the filter. Cross-coupling structure is formed on the same substrate of the resonators to improve reproducibility. A bandpass filter and a diplexer manufactured with photolithography process show excellent characteristics.

A wideband 60GHz chip antenna

A wideband 60GHz chip antenna and the module packaging are proposed as an approach to provide wideband, small, and low cost wireless devices for developing 60GHz applications in the mobile communication. The proposed chip antenna is made of LTCC and the size is 1.25 × 2 × 0.4 mm. A grounded conductor is placed between stacked patch antennas in order to obtain wideband impedance matching. A feed line using a staggered via and the land grid array are employed to obtain good reproducibility in conventional surface mount technology. In this paper, the novel chip antenna structure is shown with some measured antenna characteristics. It is demonstrated that the chip antenna with the use of low-loss LTCC enables better radiation efficiency in comparison with patch antennas integrated into PCBs.