Microstrip Stepped-impedance Hairpin Resonator Research Articles

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

A new compact microstrip two-layer bandpass filter using aperture-coupled SIR-hairpin resonators with transmission zeros

A new design of a compact two-layer bandpass filter using aperture-coupled microstrip stepped-impedance hairpin resonators is proposed and investigated in this paper. The proposed filter is composed of four stepped-impedance hairpin resonators located on two stacked microstrip layers, and the couplings between the resonators on the upper layer and those on the lower one are obtained by using three coupling apertures etched on a common ground plane placed between the two layers. In addition, the use of tapped input/output couplings allow this bandpass filter to generate two independent transmission zeros. A full-wave simulator is used to design the proposed structure and calculate the aperture coupling coefficients. With this two-layer configuration, the proposed filter becomes very compact and occupies a small space. To demonstrate the proposed design, a four-order bandpass-filter prototype was designed, fabricated, and tested at 2.14 GHz. Furthermore, a single-layer filter prototype was also designed and fabricated at the same frequency band and then compared to the first one. As a result, a significant reduction of approximately 50% was achieved. These features make the proposed structure suitable for compact and high-performance circuit component designs in microwave circuits.

A 60‐GHz GaAs micromachined slow‐wave bandpass filter using a microstrip stepped‐impedance hairpin resonator

AbstractIn this paper, a new microstrip stepped‐impedance hairpin resonator (SIHR) slow‐wave bandpass filter (BPF) using a dielectric‐supported air‐gapped microstrip line (DAML) via surface micromachining on GaAs substrate is proposed. The slow‐wave periodic structures utilize the parallel‐ and series‐resonance characteristics of the resonators to construct a band‐pass filter. The proposed slow‐wave band‐pass filter is designed to produce a passband of 10% at the fundamental frequency of 60 GHz. It exhibits insertion loss of 2.23 dB, return loss of better than 15 dB, and a stopband greater than 35 dB. This filter is useful for many millimeter‐wave system applications. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 86–89, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21089

Compact microstrip stepped-impedance hairpin resonator low-pass filter with aperture

A new microstrip stepped-impedance hairpin resonator (SIR) low-pass filter (LPF) using aperture is proposed. This filter has the advantages of compact size and easy fabrication. Also, it provides a very sharp cutoff-frequency response with low insertion loss of 0.13 dB and wide-stopband characteristic. The filter is useful for many microwave-system applications. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 517–520, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21033

Compact elliptic-function low-pass filters using microstrip stepped-impedance hairpin resonators

A compact elliptic-function low-pass filter using microstrip stepped-impendance hairpin resonators and their equivalent-circuit models are developed. The prototype filters are synthesized from the equivalent-circuit model using available element-value tables. To optimize the performance of the filters, electromagnetic simulation is used to tune the dimensions of the prototype filters. The filter using multiple cascaded hairpin resonators provides a very sharp cutoff frequency response with low insertion loss. Furthermore, to increase the rejection-band bandwidth, additional attenuation poles are added in the filter. The filters are evaluated by experiment and simulation with good agreement. This simple equivalent-circuit model provides a useful method to design and understand this type of filters and other relative circuits.

Compact lowpass filter using stepped impedance hairpin resonator

A novel microwave lowpass filter using a microstrip stepped impedance hairpin resonator is proposed. This filter has the advantages of compact size, easy fabrication, and sharp cutoff frequency response. The filter is useful for many microwave system applications.