Journal ArticleDOI
On the development of superconducting microstrip filters for mobile communications applications
TLDR
In this paper, an eight-pole planar high-temperature superconducting (HTS) bandpass filter with a quasi-elliptic function response is described.Abstract:
This paper presents recent developments of an eight-pole planar high-temperature superconducting (HTS) bandpass filter with a quasi-elliptic function response. A novel planar filter configuration that allows a pair of transmission zeros to be placed at the band edges is described. The miniature HTS filter has a fraction bandwidth less than 1% and is designed for mobile communication base-station applications to increase sensitivity and selectivity. Design considerations including filter characteristics, design approach, sensitivity analysis and unloaded quality factor of resonators are addressed. The filter was fabricated using double-sided YBCO thin film on an MgO substrate of size 0.3/spl times/22.5/spl times/39 mm. Very good experimental results were obtained with the filter cooled using liquid nitrogen. The minimum passband loss was measured to be approximately 1 dB. The passband width at points 1 dB down from the minimum loss point was 12.8 MHz for a center frequency of 1738.5 MHz. High selectivity was achieved with a 30-dB rejection bandwidth of 16 MHz.read more
Citations
More filters
Book
Microstrip filters for RF/microwave applications
TL;DR: In this paper, the authors present a general framework for coupling matrix for Coupled Resonator Filters with short-circuited Stubs (UWB) and Cascaded Quadruplet (CQ) filters.
Journal ArticleDOI
Compact, low insertion-loss, sharp-rejection, and wide-band microstrip bandpass filters
Lung-Hwa Hsieh,Kai Chang +1 more
TL;DR: In this paper, a bandstop filter based on a ring resonator with direct-connected orthogonal feed lines was proposed for reducing the interference in full duplex systems in satellite communications.
Journal ArticleDOI
On the performance of HTS microstrip quasi-elliptic function filters for mobile communications application
TL;DR: The latest experimental results of novel HTS preselect bandpass filters, including those encapsulated with a low-noise amplifier in an RF module are presented, showing very promising performance.
Journal ArticleDOI
Phenomenological model of the microwave surface impedance of high-Tc superconducting films
TL;DR: In this paper, a modified phenomenological model of the microwave surface impedance is proposed based on the experimental data of measurements of microwave characteristics of high-temperature superconducting (HTS) films.
Patent
Distributed element filter
TL;DR: In this article, a distributed element filter is realized which has bandpass characteristics realizing both a flat amplitude characteristic and a flat group delay characteristic throughout the passband at the same time, while realizing transmission zeros in the stopbands.
References
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Book
Foundations for microwave engineering
TL;DR: This paper presents a meta-modelling architecture for waveguiding systems that automates the very labor-intensive and therefore time-heavy and expensive process of designing and installingWaveguiding Systems.
Journal ArticleDOI
Couplings of microstrip square open-loop resonators for cross-coupled planar microwave filters
TL;DR: In this article, a cross-coupled planar microwave filter using coupled microstrip square open-loop resonators is proposed, and a method for the rigorous calculation of the coupling coefficients of three basic coupling structures encountered in this type of filter is developed.
Journal ArticleDOI
Theory and experiment of novel microstrip slow-wave open-loop resonator filters
TL;DR: In this article, the theory and experiment of a new class of microstrip slow-wave open-loop resonator filters is presented, and two filter designs of this type are described in detail.
Journal ArticleDOI
Dielectric properties of single crystals of Al/sub 2/O/sub 3/, LaAlO/sub 3/, NdGaO/sub 3/, SrTiO/sub 3/, and MgO at cryogenic temperatures
TL;DR: In this article, a dielectric resonator technique was used for measurements of the permittivity and loss tangent of one crystalline ferroelectric substrate, SrTiO/sub 3, in the temperature range 20-300 K at microwave frequencies.
Journal ArticleDOI
Relative permittivity and dielectric loss tangent of substrate materials for high-Tc superconducting film
TL;DR: In this article, the authors measured the relative permittivity and dielectric loss tangent of substrate materials for high-Tc superconducting films at 18-300 K and at 5-10 GHz using the cavity-resonator method.