Title :
A compact multilayer liquid crystal polymer VHF bandpass filter
Author :
Shilong Qian ; Jiasheng Hong
Author_Institution :
Sch. of Eng. & Phys. Sci., Heriot-Watt Univ., Edinburgh, UK
Abstract :
This paper presents a novel compact VHF bandpass filter with a superb performance in the upper stopband. For the first time, to the authors´ knowledge, such a bandpass filter with moderate bandwidth is designed and manufactured using multilayer liquid crystal polymer (LCP) technology. Unlike coupled distributed-resonators based filters, this design has a very wide spurious free upper stopband and the 2nd harmonic only appears at about 9.4 times the center frequency. Measured on a HP8510B network analyzer, the design shows a better than - 70dB upper stopband attenuation, which is limited by the noise floor. Implemented as a 5-metal-layer LCP module, the VHF-band filter has a size of 56.7mm × 13.75mm × 0.4mm, which is only 0.074 λg × 0.018 λg × 0.00052 λg, where λg is the guided wavelength at the center frequency 250 MHz. Both simulated and measured responses are presented and a good agreement between them has been observed.
Keywords :
VHF filters; band-pass filters; liquid crystal polymers; network analysers; 5-metal-layer LCP module; HP8510B network analyzer; LCP technology; VHF bandpass filter; compact multilayer liquid crystal polymer; frequency 250 MHz; spurious free upper stopband; stopband attenuation; Band-pass filters; Filtering theory; Microwave filters; Nonhomogeneous media; Passband; Resonator filters; Superconducting filters; LCP; bandpass filter; miniature filter; multilayer;
Conference_Titel :
Microwave Conference (EuMC), 2013 European
Conference_Location :
Nuremberg