An Ultrawideband Quasi-Reflectionless Filtering Power Divider Based on LTCC Technology

Abstract

In this article, a quasi-reflectionless (QR) bandpass filtering power divider (FPD) that features ultrawideband (UWB) performance utilizing low-temperature cofired ceramics (LTCCs) technology is presented. Good QR performance is achieved by the absorptive bandstop filtering (ABSF) section formed with a T-shaped microstrip structure and an absorptive resistor. The wide passband and excellent power division are achieved by utilizing a simple three-line coupled structure (TLCS). Moreover, the employment of LTCC technology enables the arrangement of these sections across multiple layers to achieve a compact size. Finally, to facilitate measurement, we design and fabricate a testing fixture. The measured results demonstrate that our FPD operates at a center frequency of 6.8 GHz, achieving a fractional bandwidth (FBW) of 64.7%. It exhibits QR characteristics from 1 to 13 GHz, with a size of only $10\times 6\times 0.6$ mm3.