A quick and simple method for estimating the transmission or insertion loss of an acoustic filter

✍ Scribed by Stig Söderqvist

• Publisher: Elsevier Science
• Year: 1982
• Tongue: English
• Weight: 257 KB
• Volume: 15
• Category: Article
• ISSN: 0003-682X
• DOI: 10.1016/0003-682x(82)90023-8

✦ Synopsis

A method is presented by which the dominating term in the expression for TL or IL can be set up without using the complete equation system. This dominating term is the one that contains the highest power of Ac/A p (chamber area divided by pipe area). The approximation is valid everywhere except at the filter resonances where sine and cosine factors contained in the term tend to zero. In practice, however, this is not a very serious limitation.

The approximation is also invalid at low frequencies where the length of chambers and pipes is smaller than about 12"5: per cent of the wavelength. If this frequency region is of interest a lumped-element description of the filter can be used.