Design of compact filtering rat-race hybrid with /2-resonators

作者：Lu, Yun-Long; Wang, Yi; Hua, Changzhou^*; Liu, Taijun

来源：Electronics Letters, 2016, 52(21): 1780-1782.

DOI：10.1049/el.2016.2225

• resonator filters
• band-stop filters
• band-pass filters
• invertors
• resistors
• compact filtering rat-race hybrid coupler
• improved upper stopband
• coupled-2-resonator
• -4-transmission line
• 3-4-transmission line
• bandpass filtering
• k-inverter
• second-harmonic suppression
• circuit topology
• resistor
• frequency 1
• 27 GHz
• gain 20 dB

A novel compact filtering rat-race hybrid coupler with improved upper stopband is presented. Four coupled /2-resonator pairs are utilised to replace the /4- and 3/4-transmission lines in the conventional hybrid. Each coupled /2-resonator pair exhibits a bandpass filtering response and acts as a K-inverter. Eight resistors are placed at the centre of the /2-resonators to suppress the second-harmonic. For verification, a filtering rat-race hybrid is implemented with a centre frequency of 1.27 GHz and 20 dB rejection band of 2.73 f(0). Good in-phase and out-of-phase characteristics are obtained. The proposed device has a simple circuit topology, compact size and good performance.

• 出版日期2016-10-13
• 单位宁波大学