Tables 4.1 and 4.2 list the superconductive rf/microwave device development activities in Japan and the United States, including both LTS and HTS technologies. Clearly the number of participants and the diversity of devices is greater in the United States. In Japan, the firms performing the most focused wireless applications work are in two formal alliances:

  1. Advanced Mobile Telecommunication Technology, Inc. (AMTEL), formed under the aegis of the Japan Key Technology Centers program, joins ALPS Electric and Denso.
  2. The "Western Alliance," formed through interactions with Prof. Tanaka, Vice President of the International Superconductivity Technology Center (ISTEC) and Director General of the Superconductivity Research Laboratory, joins Kyocera, Matsushita, and Sumitomo.

Table 4.1
Microwave Device Development in Japan
Thin-Film Devices Developer Device Type(s)
NEC Microstrip filters, resonator-oscillators, delay line memory
  • ALPS Electric
  • Denso
Microstrip filters
Western Alliance:
  • Matsushita
  • Sumitomo
  • Kyocera
Microstrip and disk filters
ISTEC JJ mixer in antenna
KARC LTS resonator-oscillator and LTS mixer in antennas
Bulk Devices Saitama University Cylindrical filters
Table 4.2
Microwave Device Development in the United States
Thin-Film Devices Developer Device Type(s)
Lucent Technologies
Microstrip and lumped filters
STI Microstrip, lumped, and switchable filters
SCT (ceased operations, 1998) Microstrip, tunable filters
Com Dev
Microstrip and dual-disk filters
MIT/LL Microstrip and disk filters, delay lines, and phase shifters
Northrop Grumman Microstrip circuits
University of Maryland Tunable filters and high power effects
NIST Detectors and voltage standards
JPL Detectors
High power effects
Stanford High power effects
NRL Microstrip filters, phase shifters
SUNY at Stony Brook Oscillators
Thick-Film Devices ISC Cylindrical filters
* Conductus does much of its work independently of Lucent.
** DuPont does work both together with and independently of Com Dev.

The nature of the alliances is described more fully in the relevant site reports (Appendix B) and in Chapter 8 on collaborative superconducting electronics projects in Japan. The Japanese collaborations very much resemble the vertically integrated corporations that are the dominant corporate model in Japan. In contrast, the U.S. community has several small and aggressive entrepreneurial firms (plus DuPont) pushing thin-film technology, and there is substantial participation in device development and underlying phenomenology by government laboratories and universities. While it is the norm in Japan that these R&D activities are concentrated among the large companies, it is noteworthy that only one university (Saitama University) has substantial rf/microwave filter activity, and that effort is not addressing thin-film technology. In Japan, much of the training for microwave work occurs in industry, while in the United States (and Europe) a substantial number of researchers are trained in universities.
Published: July 1998; WTEC Hyper-Librarian