Radio Astronomy in Millimetre Waves and Beyond ----- Nobeyama Radio Observatory and its Receiver Development

Nobeyama Radio Observatory has contributed to the recent progress of millimetre wave astronomy with the 45-m telescope and the millimetre array. High spatial resolution realized by these two telescopes has revealed detailed structure of the star forming regions and gas distribution in the external galaxies. The SIS mixer developed on the Nb/AlOx/Nb junction technology has been used in these telescopes and it has proved to be very low noise and quite reliable. A multi-beam SIS receiver is desired for more efficient millimetre and submillimetre wave observations.