Title :
Design of high-temperature superconducting low-pass filter for broad-band harmonic rejection
Author :
Kwak, Min Hwan ; Han, Seok Kil ; Kang, Kwang-Yong ; Ahn, Dal ; Suh, Joom-Suk ; Kim, Sang Hyun
Author_Institution :
Dept. of Electr. Eng., Gyeongsang Nat. Univ., Gyeongnam, South Korea
fDate :
6/1/2001 12:00:00 AM
Abstract :
A new type of low-pass filter based on a coupled line and transmission line theory is proposed for suppressing harmonics and spurious frequency. The seventh-order coupled-line low-pass filter with strip line configuration was fabricated using a high-temperature superconducting (HTS) thin film on MgO(100) substrate. The seventh-order low-pass filter has five attenuation poles in the stop band. Its cutoff frequency is 1 GHz with a 0.01-dB ripple level. The fabricated filter exhibits a characteristic stop band in the range from 1 to 7 GHz. A measured insertion loss at the pass-band of the HTS low-pass filter is 0.2 dB at 77 K, while the maximum return loss is 17.1 dB. These results match well with those obtained by the EM simulation. The new low-pass filter structure is shown to have attractive properties such as compact size, wide stop band range, and low insertion loss
Keywords :
UHF filters; harmonics; high-temperature superconductors; losses; low-pass filters; microwave filters; superconducting microwave devices; superconducting thin films; superconducting transmission lines; 0.2 dB; 1 to 7 GHz; 17.1 dB; 77 K; EM simulation; HTS thin film; MgO; attenuation poles; broad-band harmonic rejection; characteristic stop band; coupled line theory; cutoff frequency; high-temperature superconducting low-pass filter; insertion loss; return loss; spurious frequency; stop band range; strip line configuration; transmission line theory; Band pass filters; Couplings; Filtering theory; High temperature superconductors; Insertion loss; Low pass filters; Power harmonic filters; Superconducting filters; Superconducting transmission lines; Transmission line theory;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
