Tsunehisa Marumoto

A micromachined RF microswitch applicable to phased-array antennas

A mechanical microswitch has been fabricated by single crystal silicon bulk micromachining on a glass substrate. The mechanical part of the device has superior mechanical reliability and can be applied to a phased-array antenna, since the glass substrate can be easily extended to a large area, accommodating a large number of elements on it. A fabricated device was measured to have less than 0.2 dB of on-state insertion loss and higher than 13 dB of off-state isolation at 30 GHz.

Wireless D-band communication up to 60 Gbit/s with 64QAM using GaAs HEMT technology

Over 40-Gbps wireless communication in the D-band is described. 120-GHz-band transmitter and receiver modules employing direct modulation architecture are developed using 70-nm mHEMT technology for a RF amplifier and 0.1-μm pHEMT technology for an IQ modulator and a frequency doubler. The developed modules successfully demonstrate 64QAM transmission with a data rate of 42 Gbit/s occupying a bandwidth of less than 10 GHz (spectrum efficiency of 4.92 bit/s/Hz) and a BER of less than 10-3. The feasibility of 60 Gbps wireless transmission is also verified. To the best of our knowledge, this is the first time that over 40-Gbps D-band communication using a practical bandwidth of less than 10 GHz is achieved.

Analysis of phased arrays of printed microstrip patches with parasitic elements

The mutual coupling effect in phased arrays of patch elements on relatively high permittivity substrates is discussed. Mutual coupling properties of a single layer (un-stacked) patch and stacked patches with/without an air layer are compared for both port coupling and re-radiation level. To estimate the mutual coupling effects in 2-dimensional array environments, 4/spl times/4 element arrays are simulated.

120 GHz 256QAM GaAs Transceiver Module for Over-10Gbps Wireless Communications

120 GHz transceiver modules are developed to achieve over 10 Gbps point to point wireless communication. The transceiver module consists of the 120 GHz amplifier fabricated by 70 nm mHEMT technology, and the mixer with the band pass filter (BPF) fabricated by 0.13 μm p-HMET technology. The measured conversion gain is 2 dB with 1dB compression point (P1dB) of 0dBm and noise figure of 15 dB. Data transmission test based on real time hardware demodulation using FPGA shows Bit Error Rate (BER) <;10-12 at the data rate of 3.2 Gbps with 256QAM and bandwidth 500MHz (spectral efficiency of 6.4 bit/s/Hz). Wireless data transmission is applied to the module connected to a horn antenna of 23 dBi gain. The data rate of 2.4 Gbps with 64QAM at the distance of 3.7m is achieved.