An ultra miniature isolator with broadband isolation using ferrite gyrator

An ultra miniature isolator, which we call a "buffer device", characterized in broadband isolation and with no battery power consumption, is developed. It consists of a ferrite plate and two wire windings. It provides an insertion loss of 1.5 dB at 2.52 GHz and an isolation of 20 dB or more over a frequency range of DC through 3.0 GHz. The size of the buffer devices is only 3.2/spl times/2.5/spl times/1.7 mm/sup 3/. It is designed to replace power consuming buffer amplifiers in CDMA, TDMA, and W-CDMA mobile phone handsets.