Nobuyasu Takemura

Inverted-FL Antenna With Self-Complementary Structure

An inverted-FL antenna is proposal with a self-complementary structure. This unique design is realized by integrating an inverted-F antenna with a self-complementary structure and an inverted-L element. The proposed antenna with a volume of 10 times 10 times 45 mm3 achieves a constant impedance of 188 Omega without attaching a matching load required since a self-complementary antenna of an axially symmetric type has constant impedance. This antenna acquired broadband and multiband characteristics covering the GSM850/GSM900/DCS/ PCS/UMTS2100/UMTS2600 bands and the 2.5G/3.5G bands for Mobile-WiMAX by simulation and measurement.

Tunable Inverted-L Antenna With Split-Ring Resonator Structure for Mobile Phones

A design of a miniaturized tunable inverted-L antenna for mobile phones is proposed. The design integrates an inverted-L antenna with a split-ring resonator (SRR) structure. Although the use of SRRs to the inverted-L antenna achieves compact volume, the antennas radiation efficiency rapidly decreases around the SRRs resonant frequency. The decrease is avoided by using a variable capacitance diode loaded on the SRR conductor. The proposed antenna has a compact volume of

Inverted-FL antenna with self-complementary structure

1 \times 10 \times 50~{\hbox {mm}}^{3}~(0.5~{\hbox {cm}}^{3})

Experimental Evaluation of Estimating Living-Body Direction Using Array Antenna for Multipath Environment

, and can be tuned to the wide range, low frequency LTE700/GSM850/GSM900 bands (698–960 MHz). Simulation and measurement results showed the antenna obtains wideband and multi-band characteristics that enable it to cover the LTE700/GSM850/GSM900 and the LTE2600 bands.

Wave Analysis of the Aperture Field Distribution in Probe-Fed Radial Line Planar Antennas

An inverted-FL antenna is proposal with a self-complementary structure. This unique design is realized by integrating an inverted-F antenna with a self-complementary structure and an inverted-L element. The proposed antenna with a volume of 10 times 10 times 45 mm3 achieves a constant impedance of 188 Omega without attaching a matching load required since a self-complementary antenna of an axially symmetric type has constant impedance. This antenna acquired broadband and multiband characteristics covering the GSM850/GSM900/DCS/ PCS/UMTS2100/UMTS2600 bands and the 2.5G/3.5G bands for Mobile-WiMAX by simulation and measurement.

Fast estimation algorithm for living body radar

In this letter, we introduce a method that uses the radar system to observe the waves reflected from the target with the single-input-multiple-output (SIMO) array configuration to estimate living-body directions in a multipath environment for applications such as elderly monitoring. Directions of living body are estimated by the MUltiple SIgnal Classification (MUSIC) method, where the Fourier transformed channel matrix is used. Our use of the 2.4-GHz band allows greater miniaturization of the antenna than is possible with the low-frequency band used by conventional systems. Also, this method can be used in multipath-rich environments such as indoors. The experiments are carried out in a specific indoor environment as a demonstration, and the SIMO channel is measured with various subject numbers and positions. The results indicate that the proposed method can estimate living-body directions with high accuracy even in multipath environments.

Inverted-L antenna with split-ring resonator structures

Probe-fed radial line planar antennas (RLPAs) have high efficiency, because the excitation probes of the radiating elements can be fed by a standing wave in the radial line with a short-circuited termination of its end. We propose a method for the wave analysis of a probe-fed RLPA. Good correspondence has been confirmed between measured and calculated values on the aperture field distribution. By observing the parameter dependence of the feeding network, a method is proposed to achieve a uniform aperture field distribution. The method is efficient for general geometries of probe-fed RLPAs.

A study of directional antenna for recycled energy improvement in electromagnetic wave energy harvesting

The authors have proposed a direction estimation method of the living-body using array antenna in multi-path environment. However, this method has a problem that takes time as several tens of seconds. In this paper, we present a fast algorithm for estimating living-body direction. The experiment showed that the proposed method works well in estimating living-body direction with high accuracy in multi-path environment even when the observation time is less than conventional method.

Broadbanding of Printed Bell-Shaped Monopole Antenna by Using Short Stub for UWB Applications

In this paper, the authors describe the miniaturization design of an inverted-L antenna. This design is realized an inverted-L antenna with split-ring resonator (SRR) structures.

Antenna Array Calibration for Living-Body Radar

A recycled energy method using a dual directional antenna is proposed about the electromagnetic wave energy harvesting to convert electric power from electromagnetic waves in this paper. It is possible to convert much electric power by applying the dual directional antenna using the 180-degree hybrid circuit to the electromagnetic wave harvesting. In this research the recycled energy is considered by the indoor environment using the ray tracing method and it is reported that the recycled electric power by the dual directional antenna improved more than the single directivity antenna.