Shigeo Kawasaki

This research proposes an X-band high efficiency onboard SSPA for deep space missions by focusing on GaN HEMT whose remarkable material properties, such as high thermal conductivity, wide band gap, and high breakdown voltage, are suitable for high power and high efficiency applications. To develop a high efficiency onboard SSPA is one of the great issues when we consider some missions toward Mars, Jupiter, and much farther planets because of the requirements of both ultra-long distance communication and low power consumption. In this paper, results of preliminary design and evaluations of some trial productions using COTS device will be shown.

An amplifier with characteristics adjust functions was created with limited time to design the amplifier for the Student Contest of MWE2011 in necessity of other studies and researches. Normally the design and the fabrication are repeated to adjust circuit characteristics. For this study, it was applied to shorten fabrication time. The characteristic adjust functions was obtained at a tip of an open stub and using beaten-cupper tape. Further a ground of front side and back side was jointed with via holes to enhance operation stability. Additionally some capacitors were connected in parallel to prevent the circuit from oscillating.

A 2.1 GHz 200W GaN high power amplifier unit with a solid-state cooling equipment was fabricated in compact configuration. The four high power amplifier units were combined with a circular waveguide and the output power was obtained with 540W. In the high power amplifier unit, the two package-type GaN amplifiers are connected in parallel. The maximum power of 200W was realized with the Peltier device for heat sink. The high power amplifier unit shows the PAE of more than 50% with the AB-class operation under the temperature around 40 degrees. The combining efficiency of the combiner was achieved with about 80 %.

By recent progress on semiconductor devices, high power and low consumption communication systems can be realized. Due to this progress, it becomes possible to utilize the carrier energy as well as to convey the information effectively. For this purpose, the transmitter system was made with high performance such as the beam steering, and the receiver system must be realized with the small size and multi-functions of extraction of the carrier energy and of demodulation of the information out of the electromagnetic wave sent from the transmitter. In this study, a 5.8 GHz receiving and rectenna array has been developed for the small and high performed active integrated antenna in the small-sized transmitter/receiver and power-transfer / rectenna system. The module studied here has the functions of converting the carrier energy to the DC power as well as of demodulating the propagating signal. Under this concept, the rectenna array consisting of a small antenna and a detector was made.

Regarding wireless energy transmission as new application of the microwave technology, wireless communication and power transmission to a rover is reported. As the basic technologies for the wireless communication and energy transmission, a high power semiconductor device, an integrated circuit and an active integrated antenna technique are introduced. Further, the preliminary experimental results of the wireless communication and power transmission to the rover with the active integrated phased array antenna are shown.

Recent technology enables us to realize a sophisticated radar system with low cost. One of them is the active phased array antenna. Development for practical use of this technology such as satellite communication has been paid attention. Further, due to high power transmitter with precised beam control, trial of use for wireless power transmission and wireless power supply to a handy phone or a small sensor has already started. These two systems can be combined as the wireless communication and power transmission system. The recent development of the active integrated phased array antenna using this combination is introduced in this paper.

Compact and high power C-band amplifier circuit for active integrated phased array antennas was fabricated and examined. First, the hybrid type amplifier circuit with the chip type FET was designed and made. Based on this result, in purpose of downsizing, the MMIC amplifier as a driver was designed and evaluated at 5.8 GHz. The hybrid type amplifier circuit was with the gain of 24.0dB and the P1dB output of 27.4dBm. The MMIC amplifier circuit was with the gain of 27.9dB and P1dB output of 25.3dBm. In this report, these design methods and characteristics are shown.

Small and high power 5.8GHz band amplifier circuit for active integrated phased array antennas are designed and fabricated. A high power two-stage amplifier circuit was designed with FLC167WF. The maximum output power of it is 31dBm (1.3W) at 5.8GHz with gain of 13dB. Two-stage amplifier was designed with FET chip. Its P1dB is 27dBm with gain of 23dB. In purpose of downsizing, 5.8GHz MMIC amplifier and 14GHz MMIC amplifier were also designed.

Small and high power 5.8GHz band amplifier circuit for active integrated phased array antennas are designed and fabricated. A high power two-stage amplifier circuit was designed with FLC167WF. The maximum output power of it is 31dBm (1.3W) at 5.8GHz with gain of 13dB. Two-stage amplifier was designed with FET chip. Its P1dB is 27dBm with gain of 23dB. In purpose of downsizing, 5.8GHz MMIC amplifier and 14GHz MMIC amplifier were also designed.

5.8GHz band digital phase shifters for controlling a beam direction of an active integrated phased array antenna are designed and fabricated with a LTCC substrate. These are the line-switching type phase shifters using a GaAs MMIC SPDT switch. By using the LTCC technology in the phase shifter, small-sized and thin multi-layered phase shifter was realized. 3-bit phase shifters are fabricated on a LTCC substrate and their size are 7.7mm×13.9mm×0.5mm and 10.0mm×10.0mm×0.5mm. From the experimental data, it is possible to realize the 3-bit phase shifter with insertion loss of about -2.0dB±0.6dB.

The Active Integrated Antenna for wireless power transmission is considered to be one of the promising candidates for Space Solar Power System (SSPS). The AIA for SSPS requires an effective hestsink system to gain output power of over 1W as well as its compactness and high-efficiency. To realize a 2D-array configuration with utilizing the AIA concept, the heatsink structure should be configured in the limited space. In this study, an active integrated antenna with integrated heatsink structure is proposed. As the first step, amplifiers with folded-board structure with a plate heatsink are fabricated and the electrical performance is investigated.

In this report, fabrication and results of layered active integrated antenna array for application to a spacetenna of a solar power satellite are shown. First, a design method of the Push-Pull amplifier with two output ports was demonstrated, and the fabrication was performed. As a result, the output with 180-degree phase difference was obtained from each output port. Moreover, the two-element layered active integrated amplifier antenna array by directly connecting the output of the Push-Pull amplifier with a patch antenna was fabricated. From this, fundamental data of the active integrated antenna for the spacetenna were obtained.

Two types of printed electromagnetic band-gap were reported One is that with a 2-dimensional fashion applied into a microstripline for reduction of leakage in a substrate, and the other is that with a 3-dimensional structure into a planar slot antenna for minimizing unexpected radiation. Further, realization of lefi-handed material and application of negative refractive index characteristics were described by means of investigation of a whole band diagram

In this report, relationship of the microwave technology in the Space Solar Power Station (SSPS) is explained and microwave devices and circuits expected to use is also described with respect to construction and use of SSPS as a growing and developing power plant. In addition, a couple of demonstrations of the microwave devices and circuits expected to use in the transmission part are introduced.