Stepped-impedance Hairpin Resonator Research Articles

Stepped Impedance Hairpin Resonator (SIHR) based Compact Lowpass Filter with Wide Attenuation Band

ABSTRACT In this article, a compact (0.29 λg x 0.10 λg) low-pass filter (LPF) using a trisection stepped impedance hairpin resonator (SIHR) with a low insertion loss and a wide attenuation band is proposed. The microstrip structure is loaded with an L-shaped spur-line resonator and folded T-shaped stub for generating additional transmission zeroes to obtain a wider attenuation band. Moreover, an open stub is introduced into the existing structure to enrich the stopband performance of the LPF with a relative stopband rejection of almost 142 %. The proposed LPF that operates at a cut-off frequency of 1.7 GHz is suppressed up to −46 dB at the resonant frequency with a passband insertion loss of 0.35 dB. The suppression of harmonics is achieved up to 10 GHz with a suppression factor of 2. A well-matched behavior is observed in between the EM simulated, measurement, and circuit simulated results. The proposed LPF is suitable for mobile phones (1850 MHz), a global system for mobile communications (1800 MHz), and LTE communications (1700 MHz).

A Novel Printed Monopole Antenna With Stepped Impedance Hairpin Resonator Loading

In this paper, a novel printed monopole antenna loaded by a stepped impedance hairpin resonator (SIHR) with radial stubs is presented. By loading a SIHR at the bottom of the printed monopole antenna, a printed monopole antenna can be achieved. The resonant frequency of the proposed printed monopole antenna is reduced by the strong coupling between the SIHR and the printed monopole. By utilizing electromagnetic simulation software CST, the antenna is simulated and optimized. After the principle is stated, a sample antenna has been fabricated and measured to verify the predicted performance of our proposed antenna.

Lowpass Filter with Wide Stopband Based on T-Shaped Resonator Loaded Step-Impedance Hairpin Resonator

A lowpass filter with wide stopband based on stepped impedance hairpin resonator is proposed. Multiple transmission zeros are created in the stopband region by different size T-shaped resonator to achieve wide stopband. A lowpass filter with 3dB cutoff frequency (fc) at 3.2GHz is designed, simulated and fabricated. Experimental results indicate that stopband can be extended to more than 7fc with a rejection level of 20dB after loading T-shaped resonator. The insertion loss is lower than 0.4dB and return loss is better than 16dB in the passband. Excluding the feed lines, the size of the filter is less than 0.26λg X 0.06λg. The modified filter is of good value in engineering application for its small size, sharp cutoff frequency response and wide stopband.

A new filter antenna using improved stepped impedance hairpin resonator

AbstractIn this letter, a filter antenna based on novel wide stop‐band low‐pass filter has been presented. The introduction of mushroom cell makes smaller structure and wider stop‐band of the antenna. The filter antenna works in the frequency from 1.8 to 2 GHz (10.5%), and exhibits a good out‐band rejection characteristic that the maximum frequency of the stop band is 13 GHz, which is 6.8 times of the central frequency. The measured results show a good agreement with simulated results.

Miniaturized lowpass filter with wide band rejection using modified stepped-impedance hairpin resonator

Miniaturized lowpass filter with wide band rejection using modified stepped-impedance hairpin resonator

Compact microstrip lowpass filter with ultra-sharp roll-off and ultra-wide stopband using stepped impedance Hairpin resonator

A novel microstrip lowpass filter (LPF) with very sharp roll-off, compact size and ultra-wide stopband is presented in this paper. The structure consists of modified stepped impedance Hairpin resonator and a circular patch as a suppressor. The proposed LPF has the cut-off frequency of 1.07GHz. The simulation results indicated that the transition-band of the proposed LPF is 0.09GHz from −3 to −20dB. Maximum insertion-loss at about 80% of the passband is 0.1dB. The proposed LPF has been designed, fabricated and measured. From the measurements, good agreements with the simulated results are obtained. Also, an ultra-wide stopband was achieved. Proposed LPF has an ultra high figure-of-merit (FOM) of 151,523, which shows its strong efficiency.

Compact gradually variational stepped impedance resonator band‐stop filters

ABSTRACTThis article proposes a novel gradually variational stepped impedance hairpin resonator. Two band‐stop filters are proposed which are using the novel gradually variational stepped impedance hairpin resonator with defected ground structure or not. The filters have many remarkable advantages by using resonators, such as compact size, high selectivity, and simple structure. Good agreement between the simulated results and the measured results is achieved. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1–3, 2014

Miniaturized Dual-Band Bandpass Filter with Multiple Transmission Zeros

A miniaturized dual-band bandpass filter with high frequency selectivity using stepped-impedance hairpin resonators is presented. The proposed filter consists of two sets of short-circuit centered stepped-impedance hairpin resonators, one of which is embedded in the other one to obtain two passbands. Multiple transmission zeros are employed via introducing mixed electric/magnetic coupling and source-load coupling simultaneously for high frequency selectivity. A 2.4-/5.2-GHz dual-band bandpass filter is designed and fabricated to demonstrate the proposed method. The measurement results show six finite transmission zeros in the stopband, located at 2.04, 3.67, 4.58, 5.89, 10.63, and 15.73 GHz, respectively. And the circuit only occupies 6.70 × 10.25 mm2.

A compact high temperature superconducting bandpass filter for integration with a Josephson mixer

A compact eight-pole high temperature superconducting (HTS) filter is designed for the RF signal input of an HTS Josephson mixer. The filter has 18.2% fractional bandwidth centered at 11 GHz. A stepped-impedance hairpin resonator is employed to minimize the filter size. The obtained filter size is 10 mm × 2.79 mm, which is very compact. The monolithic HTS Josephson frequency down-converter that incorporated this new filter demonstrated the highest conversion efficiency to date for an HTS Josephson mixer. Both the filter and the on-chip HTS circuit module were fabricated on a 0.5 mm thick MgO wafer with a single-sided YBCO film. The design, simulation, and experimental characterization of the HTS filter are presented in this paper. The early measurement results of the integrated HTS down-converter incorporated this filter are also described.

Compact Continuously Tunable Microstrip Low-Pass Filter

A compact continuously varactor-tuned low-pass filter using microstrip stepped-impedance hairpin resonators is proposed in this paper. A detailed theoretical analysis for the performance tuning mechanism is illustrated by using equivalent circuit models. The experiment results are provided to validate the proposed filter. From the measured results, it is found that five varactor diodes with two applied bias voltages used in the proposed design work well as a flexible tuning network, which not only provide a wide frequency tuning range of 46% from 1.60 to 2.94 GHz, but also offer an ability of selectivity controlling by using different applied voltages. Furthermore, the proposed filter using multiple cascaded hairpin resonators provides a very sharp cutoff frequency response with low insertion loss in each state, together with a wide and deep stopband with a rejection level greater than 20 dB. Good agreement between the measured and simulated results can be observed finally.

The use of lattice networks for modelling symmetric transmission line components and discontinuities

This article proposes the lattice network as a beneficial alternative to T- and topologies for modeling symmetric transmission line discontinuities and components.The lattice network presents some important features, which make it a powerful tool to find realizable equivalent circuits. The limitations of the T- and topologies and the validity of the lattice network in terms of realizability are highlighted in this article through two microstrip components: a dumbbell-shaped defected ground structure and a microstrip stepped-impedance hairpin resonator. Moreover, the lattice image impedance is proposed here as a parameter that allows determining whether a branch of the network is predominant. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:636–639, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27385

COMPACT MICROSTRIP BANDPASS FILTER USING MINIATURIZED HAIRPIN RESONATOR

A compact microstrip bandpass fllter using miniaturized hairpin resonators is presented in this letter. Two modifled stepped impedance hairpin resonators connected by parallel coupling are designed for the bandpass fllter. The proposed miniaturized hairpin resonator is composed of a microstrip line and rectangular ring structures between parallel high impedance lines. A big capacitance in the hairpin resonator is provided by the gaps of rectangular ring structures in the parallel high impedance lines. Therefore, the proposed bandpass fllter using the hairpin resonators has a low insertion loss, low return loss and compact size. The proposed bandpass fllter with a center frequency of 4.96GHz is designed with EM full wave simulator IE3D and verifled with experiment.

Design Of Compact, Wide Stopband Bandpass Filter Using Stepped Impedance Resonator

A compact bandpass filter (BPF) with wide stopband characteristics using stepped impedance resonator (SIR) is presented. To improve stopband performance, a miniaturized short-circuit centered stepped impedance hairpin resonator (SCSIHR) with internal parallel coupled lines is proposed. Owing to the canceling effect of the mixed couplings, multiple transmission zeros can be obtained in the stopband. The odd- and even-mode analysis is applied to the proposed SCSIHR and the filter. A new BPF centered at 2.17GHz has been designed and fabricated to verify the validity of the proposed method. The measurement result shows four finite transmission zeros in the stopband, locating at 1.63 GHz, 3.99 GHz, 6.09 GHz, 14.15 GHz, respectively. The spurious frequencies are suppressed in a wide range from DC to 1.86GHz and 2.8GHz to 16.5GHz with suppression better than 20 dB. And the circuit only occupies 6.70 × 8.35mm2.

Novel flux concentrator with a single CSRR surrounded by a resonator for radio frequency superconducting quantum interference device

A novel flux concentrator surrounded by a resonator is proposed in this paper. A complementary single split ring resonator (single CSRR) is introduced for the flux concentrator, while the resonator surrounding the flux concentrator employs a third-order stepped-impedance hairpin resonator (SIR). High frequency structure simulation software ANSYS HFSSv.11 is used to simulate the proposed flux concentrator and resonator. Moreover, the single CSRR is analyzed theoretically. Simulation and theoretical results shows that the novel flux concentrator surrounded by a resonator introduces a single CSRR, which improves the flux focus effect of the concentrator significantly, and so enhances the performance of coupling between the RF SQUID and the flux concentrator (the coupling coefficient ksc is improved 2 times) and increases the effective area to 1.227 mm2.

Compact wide-stopband lowpass filter using stepped impedance hairpin resonator with radial stubs

A compact lowpass filter using a stepped impedance hairpin resonator is presented. To achieve wide stopband rejection, radial stubs were introduced. The new lowpass filter has been analysed, simulated and fabricated. Measured results are in good agreement with the electromagnetic simulation, and the circuit only occupies 0.08λg×0.08λg.

Design of stepped‐impedance hairpins band‐pass filter with wide stopband performance

AbstractIn this article, the band‐pass filter (BPF) of stepped‐impedance hairpin (SIH) design having a very wide stopband performance was proposed.The filter composed of two SIHs connected by a narrow bended microstrip with the latter's middle point shorting to the ground through a via hole. A long narrow coupled microstrip was used to couple I/O signal to/from the SIH resonators. The filter operated at a quarter‐wavelength resonance condition was built for WLAN IEEE 802.11b/g (2.4/2.45 GHz) applications. The filter's upper stopband had its frequency range measured from 2.76 to 23.08 GHz with the criterion of the signal rejection levels greater than 20 dB. The stopband's upper‐end is over 9.5 f0 (with central frequency, f0 = 2.44 GHz). Experiment was conducted for the circuit validation and a good agreement was observed between the measurement and simulation. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1405–1408, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25179

A COMPACT LOW-PASS FILTER WITH SHARP CUTOFF AND LOW INSERTION LOSS CHARACTERISTIC USING NOVEL DEFECTED GROUND STRUCTURE

In this paper, a compact stepped-impedance hairpin resonator (SIHR) low-pass fllter (LPF) with an improved split-ring resonator defected ground structure (ISRR DGS) and two elliptical DGSs is presented. The proposed LPF exhibits the advantages of low insertion loss, sharp cutofi characteristic, wide stopband over the ordinary LPFs. The introduced DGSs are presented to improve the in- band and out-band characteristic. An equivalent RLC circuit model of the two kinds of DGSs is presented and analyzed. Combining with these two structures, a new SIHR LPF having 3dB cutofi frequency of 2.5GHz is fabricated and measured. Measured results show that the selectivity of the proposed LPF is more than 100dB/GHz and the insertion loss is less than 0.5dB in the passband. A wide stop-band bandwidth with 20dB attenuation from 2.58 up to 7.5GHz is achieved. Moreover, the occupied area is only 20 £ 25mm 2 .

A novel asymmetric stepped‐impedance hairpin resonator and its filter application

AbstractIn this article, a newly asymmetric stepped‐impedance hairpin resonator (SIR), comprised of a meander line and a pair of symmetric parallel coupled lines, is presented to implement circuit reduction. Moreover, a compact filter is designed and constructed by using this novel asymmetric SIR and a slotted ground plan for spurious suppression. This proposed low‐pass filter was designed, fabricated, and measured. The experimental results of the filter have a good agreement with the simulated results. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 875–876, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24205

A COMPACT X-BAND RECEIVER FRONT-END MODULE BASED ON LOW TEMPERATURE CO-FIRED CERAMIC TECHNOLOGY

This letter presents a compact low temperature co-fired ceramic (LTCC) receiver front-end module integrating 9 building blocks. The receiver is a twice-frequency-conversion front-end module with image rejection, works at X-band, consists of an X-band embedded image rejection band-pass filter (BPF), an L- band multilayer image rejection quasi-ellipitc BPF, two monolithic microwave integrated circuit (MMIC) low noise amplifiers (LNAs), two intermediate frequency (IF) amplifiers, two mixers, a IF BPF, and some lumped passive components. All MMICs are mounted into pre- making cavities in the three layers LTCC substrate of the top surface, and the interconnection between MMICs and surface microstrip-line is established by bond wires. A multilayer five-pole Chebyshev interdigital BPF is developed as the first image rejection filter, and a four-pole quasi-elliptic BPF composed of stepped-impedance hairpin resonator and miniaturized hairpin resonators that can be coupled through the apertures on the common ground plane is proposed for as the second image rejection filter. The developed X-band receiver front-end module is fabricated using twenty layers LTCC dielectric substrate, which has a compact size of 30 × 20 × 20 mm 3 (including the metal cavity). The measured receiver gain and noise figure are more than 32 dB and less than 4 dB, respectively. The first and second image rejection is better than 28 dB and 40 dB, respectively. Compared with conventional receiver front-end module using hybrid microwave integrated circuit (HMIC) technology, the proposed receiver module not only has compact size, but also has good performance.

An ultra‐wide bandpass filter with good out‐of‐band performance

AbstractAn ultra‐wideband microstrip filter with good out‐of‐band performance is designed and demonstrated. The filter design is based on a circuit model for an optimum short‐circuited stub transmission‐line filter whose unit elements or connecting lines are nonredundant. Substituting the connecting lines by the lowpass filter using stepped impedance hairpin resonator, the undesired spurious bands can be efficiently suppressed, and the designed filter length is reduced. According to the different requirements, the broadband bandpass and lowpass filter can be independently designed and modified, which makes the filter more convenient and easily implemented. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1735–1737, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23517