Miniaturized High Temperature Superconducting Bandpass Filter Based on D-CRLH Resonators

A microstrip folded compact wideband band‐pass filter with wide upper stopband

“…Over the last decade, band-pass filters have been realized using two main methods: (1) planar microstrip transmission lines and (2) surface acoustic-wave (SAW) technology. Band-pass microstrip filters can be categorized into five techniques as follows: (1) transversal signal interaction [1,2], (2) series, shunt, and ring resonator-based filters [3,4], (3) the multi-mode resonator (MMR) and step impedance resonator (SIR) [5][6][7], (4) coupled lines and open-/short-circuited stubs [8][9][10][11], and (5) dual-composite right/left-handed (D-CLRH) structures [12][13][14][15]. In Feng et al [2] two transmission paths consisting of a short-circuited stub and two open coupled lines were used with bandwidths of 61.7% and 48.2%.…”

“…In Shen et al [15] a new compact dual-mode based on a dual-composite right-/left-handed resonator with an 88% size reduction was proposed; four prototypes were discussed with 23.3%, 26%, 14.5%, and 17.93% fractional bandwidths and a minimum insertion loss of 0.43 dB. A novel high-temperature superconducting dual-composite right-/left-handed resonator was proposed in Guan et al [13] that was constructed by microstrip spiral coupled lines and microstrip high-impedance lines. The proposed filter achieved a bandwidth of 6.9% and insertion loss of 0.045 dB with a compact 0.07 λ g  0.06 λ g size.…”

Design of compact high temperature superconducting dual‐band filter using dual‐composite right‐/left‐handed resonators

“…Therefore, it is still a challenge to realize preferable filtering performance with maintaining miniaturization. Nowadays, one way to design microwave equipment with the advantages of ultra‐compact size is to use composite materials that have both negative dielectric constant and magnetic permeability 13–17 . In References 13,14, the CRLH resonator is used to construct two passbands, but the IL and filtering performance are still poor, and there are always via‐holes in the structure.…”

“…Compared with resonators based on CRLH, D‐CRLH has the advantages of the simple structure without via‐hole. Therefore, two D‐CRLH resonators in Reference 17 are cascaded to design BPF. However, there are few publicly published literature reports on the D‐CRLH‐based dual‐band HTS filter.…”

“…Nowadays, one way to design microwave equipment with the advantages of ultra-compact size is to use composite materials that have both negative dielectric constant and magnetic permeability. [13][14][15][16][17] In References 13,14, the CRLH resonator is used to construct two passbands, but the IL and filtering performance are still poor, and there are always via-holes in the structure. In order to reduce the IL, a series of BPFs have been proposed using hightemperature superconducting (HTS).…”