LC FILTER

LC-Filter[1]Application Note AN028

LC filter with improved high-frequency attenuation
By K. H. Torvmark

Keywords
LC filter Harmonics T-type filter

Introduction
This application note describes an improved T-type LC filter that can be used to further attenuate harmonics if a standard Pi-type filter (such as the one used in many of Chipcon’s development kits) is not sufficient. This T-type filter provides much better stop-band attenuation than a Pi-type filter due to improved insulation between input and output. Measured results for a filter for operation in the 915 MHz band are also presented.

SWRA064

Page 1 of 8

Application Note AN028

Harmonics
When designing an RF power amplifier, there is always a trade-off between linearity and efficiency. Since power amplifiers used in low-power radio sy