Wireless Communication Group

Various techniques such as Massive-MIMO, In-Band Full-Duplex, and OAM have been proposed for high-speed and high-capacity wireless communications. We aim to develop RF circuits that are the keys to realizing these technologies. Our targets range from portable devices to small cell/femtocell base stations, and we are studying value-added, power-efficient, and highly tunable RF circuits for each application.

In particular, we are developing a design theory for a decoupled circuit that achieve high isolation between antennas arranged in a narrow pitch using the high-frequency circuit technology we have been researching and developing. If the antennas can be placed freely in space, high isolation can be achieved by devising a three-dimensional layout.

However, when antennas are arranged on a flat surface, the only way to achieve high isolation is to increase the distance between the antennas, which increases the board size. In contrast, our decoupled circuit can achieve high isolation simply by mounting a circuit between the antennas.

Our method can also be provided as a single module. We have achieved high isolation between antennas arranged in a narrow pitch using chip components with a bandwidth of more than -30 dB and more than 130 MHz. We are currently researching the further improvement of the attenuation, broadening of the bandwidth, and design for application to various antennas.

Main Achievements