Intermediate frequency SAW filters for mobile phone application in Japanese markets

Mobile market in Japan is rapidly growing as well as Europe, North America and other countries. The major mobile phone system in Japan are PDC (Personal Digital Cellular) and PHS (Personal Handy Phone System), and the new service called cdmaOne^TM has just started since last year. And W-CDMA system is expected to start on 2001 as new generation of mobile phone system in Japan. Since these system utilize different communication method, the specifications of the intermediate frequency (IF) filters for the systems are totally different from each other and from that of European GSM and north American AMPS. In addition, tiny and light mobile phone products are preferable in Japanese market, the size of these IF SAW filters are shrinking year by year. In this paper the technical outlines of IF SAW filter for mobile phones in Japanese market and their recent trends will be described, and also their future trend will be discussed.