Session MTT17-A 10:00- Chair: --- (Kyoto University)

10:00-10:15
  (MTT17-A-1) Investigation of Multilayer Dual Band Pass Filters with Defected ground structure
  (o)Ryosuke Nakano, Yuta Takeuchi, Mikio Tuji, Hiroyuki Deguchi
  Doshisha University

10:15-10:30
  (MTT17-A-2) Quadruple-Mode Two-Stage Cavity-Type Base Station Filter
  (o)Akihiro Tsubouchi
  Ryukoku University

10:30-10:45
  (MTT17-A-3) Implementation Methodology of Handshaking Communication Using Wearable Near-Field Coupling Transceivers
  (o)Yutaro Takemoto, Ryo Takeuchi, Shin Hasegawa
  Kyoto Institute of Technology

10:45-11:00
  (MTT17-A-4) Development of 6 GHz High Stability Oscillator for Millimeter-Wave Wireless Communication and Power Transfer System
  (o)Genta Inoue
  Ryukoku University

Break time 11:00-11:15

Session MTT17-B 11:15- Chair: Yuki Utoku (Kansai University)

11:15-11:30
  (MTT17-B-1) Enhanced Phase-Shifting Nonreciprocity in Metamaterial Transmission lines with Curvatures
  (o)Junji Yamauchi
  Kyoto Institute of Technology

11:30-11:45
  (MTT17-B-2) Study on high Q pin type artificial dielectric resonator
  (o)Kei Nishikawa
  Ryukoku University

11:45-12:00
  (MTT17-B-3) Asymmetric electromagnetic field profiles along a 2-D chiral metamaterial
  (o)Nobuyuki Hisamoto, Tetsuya Ueda, Kei Sawada, Satoshi Tomita
  Kyoto Institute of Technology

12:00-12:15
  (MTT17-B-4) Wireless Power Transfer Device Using High Q Ceramic Resonator
  (o)Yoshiki Nakagawa
  Ryukoku University

Break time 12:15-13:30

Session MTT17-C 13:30- Chair: --- (Kyoto Institute of Technology), --- (Nara Institute of Science and Technology)

13:30-13:45
  (MTT17-C-1) Computational Simulation of a Rectifier for Microwave Power Transfer by a Multilayer Substrate Filter
  (o)Kouta Okazaki, Shotaro Ishino, Naoki Shinohara, Tomohiko Mitani
  Kyoto University

13:45-14:00
  (MTT17-C-2) Excitation Circuit of WPT System with FET-Switched Variable Capacitor for Impedance Matching
  (o)Satoshi Nagata
  Ryukoku University

14:00-14:15
  (MTT17-C-3) Study on Microwave Mirror for Terrestrial Wireless Power Transmission with Beamed Pilot Signal
  (o)Ryo Mochizuki
  Kyoto University

14:15-14:30
  (MTT17-C-4) Development of power receiving unit for mobile WPT with multiple moving objects
  (o)Keisuke Higaki
  Ryukoku University

Break time 14:30-14:45

Session MTT17-D 14:45- Chair: Hiroya Hojo (Ryukoku University)

14:45-15:00
  (MTT17-D-1) Improvement of Characteristics of Composite Right/Left Handed Microstrip Lines Using Impedance Matching
  (o)Akikazu Mishiro, Takuya Nakabayashi, Hiroyuki Deguchi, Mikio Tsuji
  Doshisha University

15:00-15:15
  (MTT17-D-2) Microstrip Rat-Race Circuit Utilizing Composite Right-/Left-Handed Transmission Lines Without Chip Elements
  (o)Ryoto Nakano
  University of Hyogo

15:15-15:30
  (MTT17-D-3) Equivalent Circuit Model for Zeroth-Order Resonant Antennas
  (o)Shuhei Terada, Tetsuya Ueda
  Kyoto Institute of Technology

15:30-15:45
  (MTT17-D-4) A novel concept of isovolumetric transformation for invisibility cloaks
  (o)Yuma Takano, Atsushi Sanada
  Osaka University

Break time 15:45-16:00

Session MTT17-E 16:00- Chair: --- (Doshisha University)

16:00-16:15
  (MTT17-E-1) Non-Linear Device Model Considering Thermal Effect for Pulse Operation GaN Microwave Power Amplifier
  (o)Shuto Nishida
  Ryukoku University

16:15-16:30
  (MTT17-E-2) Design of H-Plane Waveguide Mode Converter for Microwave Fryer
  (o)Shuhei Takaoka, Taro Inada, Tadashi Kawai, Akira Enokihara
  University of Hyogo

16:30-16:45
  (MTT17-E-3) Study on Active Load-Pull Measurement Method for A 2.4 GHz Band Microwave Power Amplifier
  (o)Tomohiro Kobayashi
  Ryukoku University

16:45-17:00
  (MTT17-E-4) Azimuth characteristics of radio wave propagation in a mulberry farm in 920-MHz band
  (o)Chihiro Yamada, Takumi Nishimura, Ryosuke Yoshimura, Hitoshi Shimasaki, Yuichi Kado, Masatoshi Ichida
  Kyoto Institute of Technology

(MTT17-A-1) Title: Investigation of Multilayer Dual Band Pass Filters with Defected ground structure
Author: (o)Ryosuke Nakano, Yuta Takeuchi, Mikio Tuji, Hiroyuki Deguchi
Affiliation: Doshisha University
Abstract: This paper first clarifies mechanism of the transmission zeros from considering the distribution of magnetic currents. Then the filter structure is modified by based on such mechanism by loading slot stubs and microstrip stubs. As a result, return loss in two pass band regions are suppressed more than 25dB, and insertion loss in stop band dividing two pass band is suppressed more than 20dB. Finally, the proposed filter is fabricated, and also its effectiveness is confirmed from comparing the measured results with the numerical ones.
Keywords: ultra wide band, band-pass filter, defected ground structures, Genetic algorithms


(MTT17-A-2) Title: Quadruple-Mode Two-Stage Cavity-Type Base Station Filter
Author: (o)Akihiro Tsubouchi
Affiliation: Ryukoku University
Abstract: In recent years, data traffic of mobile communication is increasing rapidly. So, additional base stations should be installed. RRH (Remote Radio Head) is a small base station connected to a main base station by optical fiber. Approximately half of the volume of RRH is occupied by filter duplexer. To realize high selectivity, 10- to 15-stage filter is required for transmitting and receiving, respectively. Thus, size reduction of the filter duplexer is very important. One approach for miniaturizing filter is to adopt a multimode resonator. Although multimode filter using ceramic resonator has been reported, ceramic resonator is expensive. Thus, the author tried to develop cavity-type quadruple-mode filter, this time. In this report, quadruple-mode two-stage filter is described. Adjustment method of coupling between two quadruple-mode resonators are investigated.
Keywords: Quadruple-Mode Resonator, Cavity-Type Filter, Base Station, Coupling


(MTT17-A-3) Title: Implementation Methodology of Handshaking Communication Using Wearable Near-Field Coupling Transceivers
Author: (o)Yutaro Takemoto, Ryo Takeuchi, Shin Hasegawa
Affiliation: Department of Electronic System Engineering, Kyoto Institute of Technology
Abstract: Near-field coupling communication (NFCC) is a communication technology that treats the surface of the human body as a transmission path by using a carrier frequency below 10 MHz. Because the radiation signal to a space is suppressed in NFCC, humans wearing an NFCC transceiver (TRX) can exchange personal information through handshaking without having to worry about information leakage. To establish stable personal information exchange, handshaking communication needs to satisfy two requirements relating to the signal propagation loss difference between standing and handshaking postures and the S/N ratio in the handshaking posture. From the equivalent circuit of the handshaking communication, we present the position of the TRXs that satisfy the two requirements. Experimental results revealed that the two requirements are satisfied when NFCC TRXs are inserted into the soles of shoes. As a result, we demonstrated that handshaking communication can be implemented by inserting TRXs into the soles of shoes.
Keywords: near-field coupling communication (NFCC), signal propagation loss, E/O-O/E probe


(MTT17-A-4) Title: Development of 6 GHz High Stability Oscillator for Millimeter-Wave Wireless Communication and Power Transfer System
Author: (o)Genta Inoue
Affiliation: Ryukoku University
Abstract: The author developed a 6GHz high stability oscillator for millimeter-wave Wireless Communication and Power TransferSystem (WiCoPT System). In this system, oscillation frequency is stabilized bydielectric resonator. Q value of resonatordetermine the stability. In a prior art, Q value of resonatorwas not so highand stability was not enough.In this research, DRO (Dielectric Resonator Oscillator) using TE01d-mode ceramic resonator was developed. TE01d-mode shows highest unloaded Q among various resonant-modes of ceramic resonator. Oscillation frequency was stabilized and output power of 15dBm was obtained. These satisfied the values required by the system design.
Keywords: Oscillator, Millimeter-Wave, Dielectric resonator, High Stability


(MTT17-B-1) Title: Enhanced Phase-Shifting Nonreciprocity in Metamaterial Transmission lines with Curvatures
Author: (o)Junji Yamauchi
Affiliation: Department of Electronic System Engineering, Kyoto Institute of Technology
Abstract: Recently, nonreciprocal metamaterials using ferrite materials have been studied actively. In this talk, we focus on 'nonreciprocity', which means the difference of transmission characteristics depending on the propagation direction. Phase-shifting nonreciprocal metamaterials are applied to microwave circuits and antennas. In phase-shifting nonreciprocal metamaterials, conventional method for obtaining nonrecirocity was asymmetric insertion of shunt inductive stubs into the center transmission lines. However, the nonreciprocity is typically so small that the application was limited. Therefore it is necessary to think of new configuration to achieve larger nonreciprocity. In my presentation, new approach to enhance phase-shifting nonreciprocity in microstrip-line-based metamaterials with a normally magnetized ferrite substrate is proposed by utilizing a combination of curvature of the line and asymmetric insertion of shunt inductive stubs. Numerical simulation and measurement results validate that the insertion of shunt inductive stubs on the inner side of microstrip-line ring enhances the phase-shifting nonreciprocity, compared to the insertion of stubs on the outer side.
Keywords: Metamaterial, Nonreciprocity, Ferrite, Curvature


(MTT17-B-2) Title: Study on high Q pin type artificial dielectric resonator
Author: (o)Kei Nishikawa
Affiliation: Ryukoku University
Abstract: In recent years, due to an increase of data traffic, it is necessary to install additional base stations. The challenge is downsizing, cost reduction, and improvement in productivity of base station filters. By using an artificial dielectric with a high dielectric constant, it is possible to reduce the size of base station filter. The authors are trying to develop an artificial dielectric resonator with unloaded Q of more than 3000 at below 3GHz. For this purpose, pin type artificial dielectric resonator is investigated. Since conductor loss is large, relations between resonance frequency and unloaded Q for structural parameters of the pin is studied by EM simulation. As a result, divided pin structure showed very good performance.
Keywords: Artificial dielectric, Pin type structure, Resonator, Base station filter


(MTT17-B-3) Title: Asymmetric electromagnetic field profiles along a 2-D chiral metamaterial
Author: (o)Nobuyuki Hisamoto, Tetsuya Ueda, Kei Sawada, Satoshi Tomita
Affiliation: Department of Electronic System Engineering, Kyoto Institute of Technology
Abstract: Recently, artificial electromagnetic structures such as photonic crystals have been reported to realize topological edge state in electric systems. The photonic crystal has the forbidden frequencies, called photonic bandgaps due to the Bragg scattering, and can control them by changing structural parameters. The band gaps are essential for topological electromagnetic state, and in the bandgap, unidirectional surface wave propagation is observed at the edge of structure with broken time-reversal symmetry or broken space-inversion symmetry. However, to the authors' knowledge, there are few publications reported on this edge state in metamaterials at the operation frequencies far below the photonic bandgaps. In this work, we have observed experimentally asymmetric electromagnetic field profile in 2-D chiral metamaterials in the microwave region. The fields are asymmetrically concentrated on one of the boundaries depending on the chirality and operation frequency. These asymmetric field profiles have reproduced well by the numerical simulation.
Keywords: metamaterial, chiral structure


(MTT17-B-4) Title: Wireless Power Transfer Device Using High Q Ceramic Resonator
Author: (o)Yoshiki Nakagawa
Affiliation: Ryukoku University
Abstract: Currently, researches on resonator-coupled wireless power transfer are actively conducted. Although coil resonators are usually used, unloaded Q of several hundred is the upper limit due to conductivity of metal. In this research, a wireless power transfer device using high Q ceramic resonator is studied. We named the device as "Wireless Power Beam device (WPB device)". The device is equipped with metal cavity and horn antenna. First, the author looked for the cause of performance degradation. Electromagnetic field distribution was simulated to make clear how the performance degradation occurs. It was found that transmission efficiency depends on height of cavity and permittivity of resonator. Then, height of cavity and permittivity of resonator were optimized. As a result, transmission efficiency was greatly improved.
Keywords: Wireless power transfer, Ceramic resonator, Metal cavity, Horn antenna


(MTT17-C-1) Title: Computational Simulation of a Rectifier for Microwave Power Transfer by a Multilayer Substrate Filter
Author: (o)Kouta Okazaki, Shotaro Ishino, Naoki Shinohara, Tomohiko Mitani
Affiliation: Research Institute for Sustainable Humanosphere, Kyoto University
Abstract: We propose a new compact rectifier for microwave wireless power transfer using a multilayer substrate filter as an output filter. First, we designed three and four layer substrate filters with an electromagnetic field simulator. As results of simulation, we obtained their filtering characteristics. Three-layer substrate filter cut the fundamental wave, and four-layer substrate filter cut the fundamental and second harmonic wave. Next, we applied each multilayer substrate filter designed above to an output filter of rectifier and simulated its rectification efficiency. The rectifier size with multilayer substrate filter was smaller than the conventional F-class load-type rectifier.
Keywords: wireless power transfer, rectifier, filter, multilayer substrate


(MTT17-C-2) Title: Excitation Circuit of WPT System with FET-Switched Variable Capacitor for Impedance Matching
Author: (o)Satoshi Nagata
Affiliation: Ryukoku University
Abstract: An impedance matching circuit for resonator-coupled wireless power transfer system is studied. Variable capacitor using FET SPST switch was developed. apacitance of FET off-state and resistance of FET on-state should be considered to design a FET switch. Off-state capacitance was reduced by parallel inductance, this time. As a result, desired performance of FET switch was confirmed by simulation and measurement. hen, FET-switched variable capacitors were incorporated in capacitive-coupled excitation circuit. Transmission performances for different transmission distances were simulated. They showed very good performances. stable transmission efficiency even when the transmission distance of the receiver is changed in the resonant coupling type wireless power transmission.In the variable impedance matching circuit, the variable capacitance of the C coupled excitation circuit was developed as a configuration to switch the combinations of the capacities of the power transmitters by the SPST switch circuit using the FET.As a result of this research, it was confirmed that the capacity of the FET could be reduced by simulation and actual measurement of the FET switch alone.Each transmission characteristic was confirmed by simulating the power transmitter by dividing it into Cke part and Ct part.We confirmed that power can be transmitted by replacing the Cke part and Ct part of the power transmitter with FET switches and simulating them.
Keywords: Wireless power transfer, Impedance matching, Capacitive-coupled excitation, FET switch


(MTT17-C-3) Title: Study on Microwave Mirror for Terrestrial Wireless Power Transmission with Beamed Pilot Signal
Author: (o)Ryo Mochizuki
Affiliation: Kyoto University
Abstract: The microwave mirror is the essential part of the terrestrial wireless power transmission system. In the system the propagation path characteristics will be vary in time. The permittivity distribution of the air is changing because of the air current. Always beaten by the wind the mirror will fluctuate in angle and shape. The fluctuations of the mirror will result in the leakage of the power outside the system and therefore in the decrease in the transmission efficiency. Some researches suggest a possible beneficial effect of the retrodirective method with beamed pilot signal on the fluctuation of the permittivity in the propagation path. We surmised that the beamed pilot signal method would compensate the decrease in the efficiency caused by the fluctuation of the mirror. We examined whether the beamed pilot signal method would decrease the power leakage. By means of FDTD, we simulated the electromagnetic field in the smaller model of the terrestrial wireless power transmission system. The result of the simulation suggests that the retrodirective system with beamed pilot signal works effectively for the installation error and the shape fluctuation of the mirror.
Keywords: microwave mirror, retrodirective, FDTD


(MTT17-C-4) Title: Development of power receiving unit for mobile WPT with multiple moving objects
Author: (o)Keisuke Higaki
Affiliation: Ryukoku University
Abstract: The potential of electric vehicle might be expanded by utilizing wireless power transfer technology. When electric power is supplied wirelessly to electric vehicle while running, some problems is arisen to supply powerfor a plurality of objects simultaneously. The authorsdeveloped a system that can supply power to multiple objects by time division manner. Power is selectively supplied by switch on the power receiving unit. A demonstration system using toy car was developed. But transfer efficiency was not so high and power handling capability was not enough to drive toy cars. In this research, to improve the performance of the switch type power receiving unit, transistor switch is studied. Transfer efficiency and power handling capability wasimproved. Using the developed unit, motors of two toy cars were rotated selectively. When wireless electric power is supplied to the electric vehicle during traveling, there arises a problem that power is supplied to a plurality of units simultaneously. Meanwhile, we are working on the development of a system that can select power temporally and supply power to multiple units. A switch is provided in the power receiving circuit on the in-vehicle side, and power is selectively supplied by switch ON / OFF, but a high voltage resistant receiving circuit capable of withstanding high output is required. In this research, in order to improve the breakdown voltage of the switch type power receiving circuit and improve the power supply efficiency, studied the transistor switch to be used, designed the switching circuit, and developed the high voltage resistant receiving circuit. Using the developed power receiving circuit, we successfully rotated the motors of two cars with a demonstration system using a toy car.
Keywords: Mobile WPT, Electric vehicles, Multiple objects, Power receiving unit


(MTT17-D-1) Title: Improvement of Characteristics of Composite Right/Left Handed Microstrip Lines Using Impedance Matching.
Author: (o)Akikazu Mishiro, Takuya Nakabayashi, Hiroyuki Deguchi, Mikio Tsuji
Affiliation: Doshisha University
Abstract: This paper proposes composed right/left handed transmission lines (CRLH-TL) consisting of arbitrarily-shaped conductor elements, which are designed by a genetic algorithm (GA). However, when the right/left handed transmission lines are constructed by these elements, the impedance inconsistent between the input/output lines and CRLH-TL often causes the unexpected transmission characteristics error and then the performance is deteriorated. So we consider the Bloch impedance of CRLT-TL, and construct the matching circuit. Design examples are demonstrated, and its effectiveness is proved from comparison of transmission characteristics between the calculated and measured results.
Keywords: Genetic algorithm, fitness function, left-handed, matching, Bloch impedance


(MTT17-D-2) Title: Microstrip Rat-Race Circuit Utilizing Composite Right-/Left-Handed Transmission Lines Without Chip Elements
Author: (o)Ryoto Nakano
Affiliation: Graduate School of Engineering, University of Hyogo
Abstract: We research Rat-Race circuits (RRCs) with compact size, very loose coupling, and broadband characteristics by utilizing composite right-/left-handed transmission lines(CRLH-TLs). RRCs dividing a microwave signal with in/out-of-phase are usually used because of the simplicity of the circuit and the design method. A conventional RRC composed of three transmission lines with a phase delay of 90 degrees and a transmission line with a phase delay of 270 degrees has large circuit area because this circuit is designed based on a distributed circuit theory. The proposed RRC consists of two right-handed transmission lines (RH-TLs), a right-handed one composed of a series inductor and a shunt capacitor, and a left-handed one (LH-TL) composed of a series inductor and a shunt inductor. However, when actually fabricating the LH-TL, parasitic components are included. Therefore, the ideal LH-TL becomes a compound line including it. The compound line is treated as a CRLH-TL in this research. We have already reported band-broadening and size-reduction techniques utilizing the CRTH-TLs. However, chip elements are used in order to realize the CRLH-TLs and application to high frequency is a problem. Therefore, in this research, we propose the RRC utilizing the CRLH-TLs composed of lumped elements without chip elements.
Keywords: Rat-Race circuit, right-handed transmission line (RH-TL), left-handed transmission line(LH-TL), composite right-/left-handed transmission line(CRLH-TL)


(MTT17-D-3) Title: Equivalent Circuit Model for Zeroth-Order Resonant Antennas
Author: (o)Shuhei Terada, Tetsuya Ueda
Affiliation: Department of Electronic System Engineering, Kyoto Institute of Technology
Abstract: An equivalent circuit model for a low-profile and zeroth-order resonant (ZOR) antennas with omnidirectional radiation in the horizontal direction and vertical polarization is proposed. Mushroom structures are one of planar 2-D composite right/left handed (CRLH) metamaterials and exhibit omnidirectional radiation patterns under the zeroth-order resonance. However, the narrow bandwidth is a serious problem for the practical use. The proposed antenna composed of a rotationally symmetric mushroom structure with a microstrip line ring placed outside the mushroom patches shows twice the bandwidth compared to the conventional and simple mushroom antennas. In the presentation, we focus on the fact that the phase relationship of the current distribution on a via in each mushroom cell contributes to the radiation gain. First, we calculated and compare current distribution along the vias for conventional and proposed wideband ZOR antenna to confirm the operation of both ZOR antennas in the electromagnetic field simulation. They are compared with numerical simulation results with the use of finite element method, showing their good agreement.
Keywords: mushroom structure, zeroth-order resonance, low-profile antenna, equivalent circuit.


(MTT17-D-4) Title: A novel concept of isovolumetric transformation for invisibility cloaks
Author: (o)Yuma Takano, Atsushi Sanada
Affiliation: Graduate School of Engineering Science, Osaka University
Abstract: In this presentation, we propose a novel concept of the isovolumetric transformation for invisibility cloaks with which the permeability is intrinsically unitary. With the proposed transformation, the permeability tensor is perfectly controlled without using the so-called eikonal approximation, leading to complete reduction of reflection and feasible implementation with nonmagnetic uniform anisotropic materials. In addition, since the transformation is completely frequency independent, cloaks based on the transformation are intrinsically wideband and low loss. We demonstrate that an invisibility cloak based on the transformation works perfectly by circuit simulations based on the equivalent circuits for TM waves in anisotropic materials.
Keywords: transformation optics, invisibility cloak, isovolumetric transformation, metamaterials.


(MTT17-E-1) Title: Non-Linear Device Model Considering Thermal Effect for Pulse Operation GaN Microwave Power Amplifier
Author: (o)Shuto Nishida
Affiliation: Ryukoku University
Abstract: Efficiency of power amplifier for microwave heating is expected to be increased. Although continuous wave is usually used for microwave heating, the performance sometimes deteriorate due to thermal problem. On the contrary, in pulse operation, transistor can operate in a prescribed performance without thermal degradation, while average output power is kept. In this research, non-linear device model considering thermal effect of GaN transistor is studied. In order to make a device model including thermal effect, current should be measured with a short pulse, width of which is as short as possible.
Keywords: Microwave power amplifier, Thermal effect, Pulse operation, Non-linear modeling


(MTT17-E-2) Title: Design of H-Plane Waveguide Mode Converter for Microwave Fryer
Author: (o)Shuhei Takaoka, Taro Inada, Tadashi Kawai, Akira Enokihara
Affiliation: Graduate School of Engineering, University of Hyogo
Abstract: In this research, we designed an H-plane rectangular waveguide TE_10 -TE_n0 mode converter for microwave fryers using microwave heating. The microwave fryer proposed in this research is heating liquid by circulating liquid through a heating unit with countless small holes that liquid pass but microwave cannot. By using the mode converter, we miniaturize the heating unit in microwave propagation direction compared with a standard rectangular waveguide propagating TE10 mode microwave. The mode converter consists of a standard rectangular waveguide and an over-mode one for TE_n0 mode and the over-mode waveguide has several metallic posts in order to match of the input port and suppress unnecessary modes. As a result of optimizing based on the H-plane planar circuit approach at a center frequency of 2.45GHz, the configuration of the converter and positions of several metallic posts are decided, and practical characteristics for microwave fryers can be realized. The validity of this design procedure is confirmed by a commercial electromagnetic simulator (ANSYS HFSS). From experimental result of oil heating by employing the six heating units, it was possible to confirm the temperature rise up to 180 degrees and the effectiveness of this system.
Keywords: Microwave heating, Microwave fryer, Waveguide mode converter, H-plane planar approach.


(MTT17-E-3) Title: Study on Active Load-Pull Measurement Method for A 2.4 GHz Band Microwave Power Amplifier
Author: (o)Tomohiro Kobayashi
Affiliation: Ryukoku University
Abstract: Passive load-pull measurement is conventionally used for characterization and design of microwave power amplifiers. However, it requires very large measurement equipment and has a limited performance. On the other hand, active load-pull measurement method, which is recently developed, overcomes these drawbacks. But, it still has some difficulties, such as the measurement system is very complicated and very expensive. In this study, basic investigation to construct an active load-pull measurement system for fundamental frequency of 2.4 GHz was carried out. A measurement system using auxiliary power amplifier and circulator was constructed and demonstrated that the highest efficiency point can be specified by changing amplitude and phase of injected reflection wave. The developed system is very simple and might contribute to cost reduction.
Keywords: Active load-pull, Microwave power amplifier, Injected reflection wave


(MTT17-E-4) Title: Azimuth characteristics of radio wave propagation in a mulberry farm in 920-MHz band
Author: (o)Chihiro Yamada, Takumi Nishimura, Ryosuke Yoshimura, Hitoshi Shimasaki, Yuichi Kado, Masatoshi Ichida
Affiliation: Department of Electronic System Engineering, Kyoto Institute of Technology
Abstract: Data collection of the radio wave propagation loss in farm fields is valuable to design a wireless network in a farm.They are used in calculating the link budget to establish a proper and efficient node arrangement. In this study, propagation losses in a 50 × 50 m mulberry field were measured in 920-MHz band with respect to the azimuthal angle of the propagation direction to arrays of bushes. They were measured in maturity stage and deciduous stage.RSSIs (Received Signal Strength Indicators) were measured at two propagation distances and converted to path losses. Antennas were placed at a height of 1.5 m while the height of the bush was 3.5 m. Moreover, horizontal and vertical polarizations were measured. The results revealed that the horizontal polarization could be less affected by the direction angle to the ridges than the vertical polarization. These data would be useful for the evaluation of link budgets to design wireless networks in a farm.
Keywords: radio wave propagation, path loss, UHF, microwave, farm, wireless sensor network