Compact stripline and air-cavity based radio frequency filter

摘要

A method is proposed for designing compact stripline and air-cavity based (SACB) RF filters, duplexers, and multiplexers. The target frequency band is 600 MHz˜3 GHz. The proposed devices feature both compact size (with 50% size reduction compared to traditional resonator air cavity design) and high power handling capability as well as low insertion-loss. In the SACB filter, striplines and cavities are used to emulate LC resonator (quasi-LC resonator). The combination of striplines and cavities forms a structure that exhibit the performance of an electric resonator circuit of inductor and capacitor (LC). The outside signal will be connected to the striplines, and the ground will be connected to the metal shield which forms the cavity. By controlling the dimensions of the stripline width and length as well as the size of the cavity, the desired filter response is achieved.

主权项

1. A radio frequency (RF) filter, comprising:
a metal-made stripline, wherein dimensions of the stripline determine a passband frequency and a bandwidth of the RF filter; a metal-wall-formed cavity housing the stripline for providing a quality factor (Q value) of the RF filter; and a plurality of supporters, each supporter is attached to the metal-wall-formed cavity to fix the position of the stripline by connecting to the stripline, wherein a first supporter is connected to one end of the stripline, wherein a second supporter is connected to another end of the stripline, and wherein a third supporter is connected to an approximate center of the stripline.