Toru Taniguchi

A low-cost and very compact wireless terminal integrated on the back of a waveguide planar array for 26 GHz band fixed wireless access (FWA) systems

A compact wireless terminal (WT) with a high-gain planar array has been developed for the Wireless IP Access System (WIPAS), which is a point-to-multipoint Fixed Wireless Access (FWA) system in the 26 GHz band. For the point-to-multipoint FWA services in rural areas, the drastic cost and size reduction of WT with the high-gain antennas and RF module is indispensable. In this paper, remarkable cost reduction of 1/10 and downsizing of 1/5 are realized by using an alternating phase fed single layer waveguide array antenna and Microwave Monolithic IC (MMIC) technologies. This terminal is 190/spl times/190/spl times/55 mm/sup 3/ in volume and less than 2.0 kg in weight which accommodates over 31 dBi very high efficiency antenna with a radome, RF module, IF modules, application specific IC (ASIC) for modem, time division multiple access (TDMA) equipment control, and medium access control (MAC). Only an Ethernet cable with 24 V dc power supply is attached on the terminal.

A highly integrated quasi-millimeter wave receiver chip using 3D-MMIC technology

A highly integrated quasi-millimeter wave receiver chip that integrates 22 circuits on a 3 x 2.3 mm chip using three-dimensional MMIC (3D-MMIC) technology is presented. The receiver MMIC operates with an LO signal in the 2.7-3.1 GHz range. This LO signal is multiplied in an integrated multiply-by-eight (X8) LO chain, resulting in an IF center frequency of 2.4 GHz. It can use low-cost VCOs and demodulators in a 2-3 GHz frequency band. The power dissipation of the MMIC is only 450 mW. It also achieved low noise (3.4 dB) and high gain (41 dB) at 26 GHz. Furthermore, it achieved a high dynamic range using two step attenuators in the RF and IF frequency bands with a new built-in inverter using an N-channel depression FET.

Multi-level QAM single-carrier high-efficiency broadband wireless system for millimeter-wave applications

In preparation for achieving the millimeter-wave ultra-broadband wireless system aimed at seamless connection with the optical communication network, we have developed key devices such as baseband signal processing SoC (System-On-Chip) with the built-in ultrahigh-speed multi-level QAM (Quadrature amplitude modulation) modem (modulator and demodulator), SiGe I/Q quadrature modulator and demodulator MMIC (Microwave Monolithic Integrated Circuit), and GaAsHEMT frequency converter MMIC. We have also prototyped the micro-mini and ultra-broadband 38 GHz band point-to-point wireless system using TDD (Time Division Duplex) mode with dynamic bandwidth assignment that adopts the configurations of separate transmission and receiving antennas capitalizing on the characteristic of smaller antenna area in the millimeter-wave band to achieve the performance that the radio clock frequency is 200 MHz and the maximum effective throughput on 16QAM is 600 Mbps.

A 60-GHz Band Compact-Range Gigabit Wireless Access System Using Large Array Antennas

A novel compact-range wireless access system is proposed for multi-Gb/s data transfer in the 60-GHz band. Large-array antennas in the access point generate a quasi-plane wave and form a stable communication zone proportional to the antenna size. The link budget based upon the Friis transmission equation is not applicable as ever in this compact-range communication system. The signal coverage up to 10 m still falls within the Fresnel region of the large-array antenna. Mobile users everywhere within the coverage receive almost constant field strength free of multipath interference. To demonstrate the viability, circularly polarized waveguide slot arrays of various sizes are designed and fabricated. After the evaluation of conventional antenna radio frequency (RF) performance, bit-error rate (BER) and signal-to-noise ratio (SNR) measurements are conducted to evaluate the prototype of a compact-range Gigabit wireless access system.

A Highly Integrated Quasi-millimeter Wave Transmitter MMIC Using 3D-MMIC Technology

A highly integrated quasi-millimeter-wave transmitter MMIC that integrates 26 circuits in a 3 mm times 3 mm area using three-dimensional MMIC (3D-MMIC) technology is presented. The power dissipation of the MMIC is only 0.54 W. It achieved a high P1 dB of 6 dBm and gain of 19 dB at 26 GHz. Furthermore, it integrated step attenuators with a new built-in inverter using an N-channel depression FET for transmit power control.

A 38 GHz-band 1 Gbps TDD FWA system using Co-polarization dual antenna with high spatial isolation

In order to realize a broadband millimeter-wave band radio communications system which enables the seamless interconnection with optical cable networks, we have developed the wireless key devices of System on Chip (SoC) which is unified from an high-speed Multi-level Quadrature Amplitude Modulation (M-QAM) modem to the network interface, and the high-order-accuracy quadrature modulator and demodulator Monolithic Microwave Integrated Circuit (MMIC) and the broadband frequency converter MMIC. By combining with these devices and the high spatial isolation antennas that are separated in transmitter and receiver and employed the characteristic of the millimeter wave efficiently, we have developed the 38 GHz-band small and broadband Fixed Wireless Access (FWA) system using Time Division Duplex (TDD) mode with adaptive radio resource control of up-link and down-link bandwidth. We have realized the performance that maximum effective throughput is 1 Gbps in single carrier 64QAM and 200 MHz of radio clock frequency, and have reached the stage of the field trial at present.

Effective throughput 1Gbps wireless system by single-carrier 64QAM for millimeter-wave applications

In preparation for achieving the millimeter-wave ultra-broadband wireless system aimed at seamless connection with the optical communication network, in 2009 we have developed the key devices such as baseband signal processing SoC (System-On-Chip) with built-in ultrahigh-speed multi-level QAM (Quadrature amplitude modulation) modem (modulator and demodulator) and gigabit Ethernet MAC (Media Access Control). We have also prototyped the micro-mini and ultra-broadband 38 GHz band point-to-point wireless system and achieved the performance of effective throughput 600Mbps on 16QAM operation, furthermore, we evaluated the performance of this system by actual operation in the field. This time, we have upgraded the resolution of ADC/DAC (Analog to Digital Converter / Digital to Analog Converter) built in this SoC and improved the performance of RF characteristics, and achieved the development prototype System with this new SoC, which enables 64QAM operation and the effective throughput of 1Gbps.

Multifunctional frequency converter MMIC for 38GHz band 600Mbps multi-level QAM wireless system

The highly integrated up and down converter MMICs which uses the GaAs_HEMT process with three-dimensional MMIC technology is presented. These frequency converters consists of a balanced mixer, RF band amplifiers, an IF band amplifier, a step attenuator, an active band pass filter and a local quadrupler. A smaller surface mount package of 5 mm × 5 mm × 1.65 mm has also developed and the MMIC chips are mounted in it, respectively. The 38GHz broadband wireless system as the ultra compact and very light weight has realized by useing these developed MMICs.

Development of baseband processing SoC with ultrahigh-speed QAM modem and broadband radio system for demonstration experiment thereof

With the aim of application to the ultra-broadband quasi-millimeter wave radio system, we have developed the baseband processing SoC (System-On-Chip) equipped with the Gigabit Ethernet interface based on the ultrahigh-speed single-carrier QAM (Quadrature amplitude modulation) modem (modulator and demodulator) and with built-in D/A and A/D converters to achieve the 38 GHz band point-to-point radio system that operates at radio clock frequency of up to 200 MHz in TDD (Time Division Duplex) system with dynamic bandwidth assignment.

Developments of the SoC for high-multi-level QAM 1 Gbps class wireless system and its evaluation with RF hardware of 38 GHz band FWA

Since 2008, we have been developing the integrated SoC, which incorporates from the ultra high speed multi-level QAM modem to the gigabit Ethernet interface, in a bid to adapt to the millimeter wave broadband wireless system. In 2009, we developed the SoC that functions on its maximum modulation clock 200 MHz, single-carrier 16QAM, and TDD, and managed to conduct field evaluation tests as a state of actual operation of 38 GHz band P-P FWA system. This time, we have increased the resolution of ADC/DAC incorporated in the SoC, and made design improvements to suppress the internal clock jitter, and finally managed to develop a prototype SoC for the wireless system, which enables 64QAM operations (on architecture of the modem, maximum multi-level is 256QAM) and also actualized an effective throughput of 1 Gbps.