Title :
Ultra selective 22-pole, 10-transmission zero superconducting bandpass filter surpasses 50-pole Chebyshev rejection
Author :
Tsuzuki, G. ; Shen Ye ; Berkowitz, S.
Author_Institution :
Conductus Inc., Sunnyvale, CA, USA
Abstract :
An ultra selective filter for 3G and 4G wireless application is presented. The demonstrated filter consists of twenty-two resonators and five cross couplings that produce ten transmission-zeros. The filter was designed at 1950 MHz center frequency with a 20 MHz bandwidth to meet existing 3G wireless applications. The measured data from the filter exhibited excellent selectivity, steeper than 30 dB/100 kHz skirt slope and 90 dB rejection at 350 kHz from the band edge. This filter surpasses the rejection of a 50-pole Chebyshev filter. To design a large number of resonators in a limited wafer area, a new compact resonator was developed. The filter was fabricated using a YBCO thin film on a 2-inch MgO wafer.
Keywords :
Chebyshev filters; UHF filters; band-pass filters; barium compounds; cellular radio; high-temperature superconductors; poles and zeros; superconducting filters; superconducting microwave devices; yttrium compounds; 1950 MHz; 20 MHz; 3G wireless application; 4G wireless application; Chebyshev rejection; MgO; YBCO; YBaCuO-MgO; center frequency; compact resonator; cross couplings; selectivity; skirt slope; superconducting bandpass filter; transmission-zeros; wafer area; Band pass filters; Bandwidth; Chebyshev approximation; Coupling circuits; Filtering theory; Frequency; High temperature superconductors; Resonator filters; Superconducting filaments and wires; Superconducting filters;
Conference_Titel :
Microwave Symposium Digest, 2002 IEEE MTT-S International
Conference_Location :
Seattle, WA, USA
Print_ISBN :
0-7803-7239-5
DOI :
10.1109/MWSYM.2002.1012250
