Compact SIDGS Filtering Power Divider With Three-Port 10-GHz Reflectionless Range

• Published in: IEEE transactions on circuits and systems. II, Express briefs Vol. 69; no. 7; pp. 3129 - 3133
• Main Authors: Li, Qingxian, Tang, Hongxin, Tang, Deshan, Deng, Zhixian, Luo, Xun
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.07.2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Absorptivity; Couplings; Filtering power divider; Filtration; Harmonic analysis; high isolation; Integrated circuit modeling; Microstrip; Network topology; Power dividers; reflectionless; Resonators; substrate-integrated defected ground structure (SIDGS); Substrates; Topology; wide stopband
• DOI: 10.1109/TCSII.2022.3165848
• ISSN: 1549-7747

In this brief, a compact high isolation filtering power divider (FPD) with wide stopband and wide-band three-port reflectionless operation is proposed. Such FPD consists of a trigonometric substrate-integrated defected ground structure (SIDGS) based resonator and three absorptive networks. The good stopband performance is achieved by using the trigonometric SIDGS. Meanwhile, the absorptive networks based on common-gate topology capable of absorbing the out-of-band reflected signals are connected to the SIDGS resonator, which provides the wideband reflectionless operation in all three ports of the FPD. To verify the mechanisms mentioned above, a FPD operated at 2.10 GHz (i.e., <inline-formula> <tex-math notation="LaTeX">\boldsymbol {f_{0}} </tex-math></inline-formula>) is fabricated, which exhibits a 42 dB stopband rejection level up to 20 GHz (i.e., <inline-formula> <tex-math notation="LaTeX">9.5\boldsymbol {f_{0}} </tex-math></inline-formula>). The measured reflectionless range with return loss lower than −10 dB is up to 10 GHz in all three ports. The core size of the FPD is about <inline-formula> <tex-math notation="LaTeX">0.36\,\,\boldsymbol {\lambda _{g}} \times 0.38\,\,\boldsymbol {\lambda _{g}} </tex-math></inline-formula>, where <inline-formula> <tex-math notation="LaTeX">\boldsymbol {\lambda _{g}} </tex-math></inline-formula> is the microstrip guided wavelength at the center frequency.