Low-loss tunable bandpass filters (BPFs) using partially magnetized ferrites is presented. A magnetic field tunable BPFs was designed based on partially magnetized yttrium iron garnet (YIG) operating at 6.17 GHz, which shows low insertion loss and a large frequency tunability of ∼ 6% under a low bias field of 100 Oe. Power handling measurement on the tunable BPF with partially magnetized YIG slab showed an IP1dB of 11.5-18 dBm within the bias field of 0 to 100 Oe, and over 30 dBm in a saturated state. © 2001-2012 IEEE.