A tunable phase shifter at X band using single-crystal yttrium iron garnet
film material grown on GGG substrates is fabricated. The phase shifter is a
fourth wavelength in the absence of a bias magnetic field. The phase can b
e tuned 120 degrees by varying the bias magnetic field from 3440 to 3720 Oe
. The resultant variation in insertion loss was 0.5 dB. Measurements compar
ed very well with calculations. (C) 1999 American Institute of Physics. [S0
021-8979(99)19508-2].