Naoki Honma

Millimeter-wave high-efficiency multilayer parasitic microstrip antenna array on teflon substrate

This paper proposes a highly efficient multilayer parasitic microstrip antenna array that is constructed on a multilayer Teflon substrate for millimeter-wave system-on-package modules. The proposed antenna achieves a radiation efficiency of greater than 91% and an associated antenna gain of 11.1 dBi at 60 GHz. The antenna size is only 10 mm /spl times/ 10 mm. Additionally, this paper describes a 60-GHz-band prototype antenna employing a multilayer Teflon substrate that is well suited to achieving high gain and a wide bandwidth. The measured performance of the prototype antenna is also presented.

Compact Six-Sector Antenna Employing Three Intersecting Dual-Beam Microstrip Yagi–Uda Arrays With Common Director

A novel compact planar six-sector antenna suitable for wireless terminal is presented. Our new antenna design yields low-profile and extremely compact multisector antennas since it allows microstrip Yagi-Uda array antennas to share director elements. Two microstrip Yagi-Uda array antennas are combined to form a unit linear array that has feed elements at both ends, only one of which is excited at any one time, and the other is terminated. A numerical analysis shows that applying a resistive load to the feed port of the terminated element is effective in reducing the undesired radiation. The radiation pattern of a six-sector antenna, which employs three intersecting unit linear arrays, is investigated, and the optimum termination condition is identified. From the results of measurements, it is found that our antenna achieves high gain, at least 10 dBi, even though the undesired radiation is suppressed. It is shown that the radiation pattern suitable for a six-sector antenna can be obtained even with a 1.83 wavelength diameter substrate, i.e., the area is 75% smaller than that of a regular antenna with six individual single-beam microstrip Yagi-Uda arrays in a radial configuration

Proposal of compact three-port MIMO antenna employing modified inverted F antenna and notch antennas

In this paper, a small three-port MIMO antenna that has a low profile is proposed for small MIMO terminals constructed in the size of a PCMCIA card. In the proposed configuration, a modified inverted F antenna with an H-shaped conductor plate is employed for the vertical polarization antenna. Also, two orthogonal notch antennas are configured around the corner of a rectangular ground plane on a dielectric substrate. These notch antennas have the radiation patterns with the horizontal polarization that are orthogonal to each other. To evaluate the validity of the proposed antenna in MIMO systems, the antenna radiation performance is studied and the channel capacity is measured using a fabricated antenna

Beam-scanning performance of Ku-band low loss MUSCAT array with open stubs

In this paper, we propose a new MUSCAT array configuration that employs open stubs at the ends of a microstrip antenna and reduces the number of varactor diodes. Each unit element group has a microstrip antenna with two varactor diodes and two microstrip antennas with one varactor diode. Compared to the configuration described in Honma et al. (2003), this proposal increases the radiation efficiency. Based on the measured results of the fabricated antenna, the phase shift property of the unit element group and the beam-scanning performance at Ku-band are described and the validity of the loss reduction effect is discussed.