In this paper, it introduces some new developments of several new LTCC microwave stereo integrated circuits, including: X-band ultra wideband balun, ultra wideband 3dB orthogonal directional couple, a new bandpass filter with highly steep band, ultra-wideband and palanar magtic T, bandpass filter with double transmission zeros, quintuple-mode dual-band filter, ultra broadband vivaldi antenna with a new type of stub, etc. In these LTCC micro-device designs' process, due to the high performance requirements of the products, it is quite difficult. Therefore, in these designs, the structure of a model is carried out according to the respective characteristics, and at the same time, the miniaturization is ensured.