Filter SAW principle in RF connector
Xiao Tian and the engineers just discussed the RF connector test often used in the filter, there are many customers do not know the filter in the RF connector, the following small days will first introduce the filter SAW principle.
The SAW filter is an abbreviation for a surface acoustic wave filter. It is a filter-specific device that uses piezoelectric materials such as quartz crystals and piezoelectric ceramics and uses its piezoelectric properties and physical properties of surface acoustic wave propagation. In the TV and VCR IF circuit, instead of the LC IF filter, the quality of images and sounds is greatly improved. Surface Acoustic Wave (SAW) is an elastic wave that is generated and propagated on the surface of a piezoelectric substrate material and whose amplitude rapidly decreases as the depth of the substrate material increases.
It consists of a substrate made of a piezoelectric material and a comb electrode fired thereon. When the input signal is input to the large-end surface of the surface acoustic wave filter, a mechanical vibration wave having the same frequency as the applied signal is generated on the surface of the piezoelectric material of the electrode. The vibration wave propagates on the surface of the piezoelectric substrate at a sound wave rate. When the wave is transmitted to the output end, the transducer composed of the comb electrode at the output end converts the sound energy into a transaction signal.
The SAW filter is composed of two transducers. The input transducer converts electrical energy into acoustic energy to emit surface acoustic waves, and the output transducer converts the received surface acoustic wave acoustic energy into electrical energy output. . The surface acoustic wave filter uses the two transducers on the piezoelectric substrate to generate surface acoustic waves and detect surface acoustic waves to complete the filtering function.
The main features of the SAW filter are: high design flexibility, analog/digital compatibility, excellent group delay time offset and frequency selectivity (optional frequency range 10MHz ~ 3GHz), small input-output impedance error, low transmission loss, anti-electromagnetic interference (EMI) Good performance, high reliability, small size and light weight (the size and weight are 1/40 and 1/30 of the ceramic dielectric filter), and can build a variety of complex functions. The features and advantages of the SAW filter are being incorporated into the requirements of modern communication system equipment and portable telephones that are light, thin, and high-frequency, digital, high-performance, and highly reliable. The shortcomings of the invention are: the substrate material is required to be expensive, and the substrate orientation, cutting, grinding, polishing and manufacturing processes are required to be high.
Shenzhen Tiankele Communication Technology Co., Ltd. specializes in the manufacture of RF connectors for 11 years. It has three professional laboratories, including mechanical, electrical and environmental, and an integrated industrial chain from machining, assembly testing and electroplating. 11 years experience R & D team, professional performance simulation software HFSS, 3D software PROE, graphics software CAD design. More than 20 professional customer service teams, 24 hours online, quick and timely response, providing one-to-one customized solutions. The pursuit of high quality products is the guarantee of Tianke Le people to customers.
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