LTCC layer-to-layer misalignment resistant coupled inductor and bandpass filter

The performance of a misalignment resistant coupled inductor (MaRCI) is verified and compared experimentally with traditional straight line coupled inductor using coupled inductor based transmission zero circuits and bandpass filters. Measurement results of 3 samples of a transmission zero circuit based on proposed MaRCI shows only 0.3% frequency variation at 1.9 GHz while traditional straight line coupled inductor gives about 3.2% variation from samples at the same LTCC substrate. Measured results of a bandpass filter using MaRCI also show more stable performance at transmission zero frequency, insertion loss and passband bandwidth as compared with filter using traditional straight line coupled inductor. EM simulation also shows similar performance improvement under misalignment.