ABSTRACT A miniaturized ultra‐wideband band‐pass filter with wide out‐of‐band suppression based on low‐temperature cofired ceramic (LTCC) technology is presented, which works from 0.74 GHz to 6.5 GHz, consisting of a highpass filter and a lowpass filter. Because of utilizing advanced LTCC technology, the big multilayer capacitors and helical‐shape inductors can be realized in multiple thin layers to overcome the large circuit size, so the size of the proposed filter is miniaturized with 6 mm × 4