Isolators,
used for radio communications equipment, such as mobile phones,
are important components that stabilize amplifier operation and
prevent cross modulation.
Many kinds of parts should be equipped in recent mobile phone to
realize many functions of the hand sets, and hard to get enough space
for these parts in it.Multi band system is started on W-CDMA system
which the isolator is used for, and smaller size parts are desired
for these mobile phone.
Figure 2: Brock diagram of RF part for W-CDMA system
Study for material on magnet, garnet and di-electric material were carried out and designs for the RF circuit and structural were proceeded to realize small size Isolator. After these studies, 2.5mm square Isolator and its production process were developed. Typical performance was shown in Figure 3 and its dimensions were shown in Figure 4.
Based on material technology, we, Hitachi-Metals have wide range production line up of Isolators which are used for not only mobile phone but base station also.
