3 results about "Band width" patented technology

A triple-band antenna for an electronic device with a communication capability comprises a first radiating body, a second radiating body, a metal base and a signal feed source. A dual-band antenna for low frequency and high frequency bands may be formed by the first radiating body. A middle-frequency band antenna and a balun may be formed by the combination of the first radiating body and the second radiating body, and the balun may be used to increase the bandwidth of operating frequencies of the intermediate frequency band antenna.

A basic metal nitrate suitable as an oxidizing agent for a gas generating agent, which is a basic metal nitrate having a good thermal stability and meeting at least one requirement of the following (a) to (d): (a) a particle diameter of 0.5 to 40 μm; (b) a degree of crystallinity having 0.4 deg or less of a half band width of the peak in the X-ray analysis; (c) an initiation temperature of weight loss being 220° C. or higher according to TG-DTA analysis; and (d) an impurity content of 1,000 ppm or less based on Na atom. Also, a gas generating composition which has a low toxicity, a high burning rate, and a low combustion temperature and which is used in a gas generator for an air bag. The gas generating composition comprises (a) tetrazole derivatives, guanidine derivatives or a mixture thereof, (b) a basic metal nitrate, and (c) a binder and/or a slag-forming agent.

The invention discloses a planar undoped heterojunction-perovskite laminated cell and a preparation method thereof, and relates to the technical field of solar cells. The cell comprises a perovskite top-layer solar cell and a heterojunction bottom-layer solar cell which are connected together, wherein the perovskite top-layer solar cell comprises a front metal electrode layer, a first transparentconductive oxide layer, a hole transport layer, a perovskite light absorption layer and an electron transport layer which are sequentially arranged from top to bottom; the perovskite light absorptionlayer comprises a perovskite layer A, a perovskite layer B and a perovskite layer C which are sequentially arranged from top to bottom; the forbidden band width of the perovskite layer A is 2.4 to 3.0ev; the forbidden band width of the perovskite layer B is 2.0-2.6 ev, the forbidden band width of the perovskite layer C is 1.9-2.2 ev; and the forbidden band widths of the perovskite layer A, the perovskite layer B and the perovskite layer C are sequentially reduced. The perovskite solar cell has the advantages that the photoelectric conversion efficiency exceeds 28%, the open-circuit voltage ishigh, and the generating capacity is increased.