Hairpin Filter Research Articles

Designing and Analysis of Microwave Hairpin Filter

Hairpin Filter is one of the most popular microwave frequency filters because of it is compact and does not require grounding. The filter is designed at center frequency of 2.44 GHz with a fractional bandwidth of 3.45%. This frequency is presenting for wireless LAN application and operates in the ISM band (Industrial, Scientific and Medical) application. There are several step to design this filter that including by determine filter specification, order of filter, low pass filter prototype elements, low pass to band pass transformation, physical dimension (width, spacing, length) and wavelength guide. The simulation of the filter will be done using IE3D and fabricate on FR4 substrate by using etching process. Improvement technique will be introduced to get better response for scattering parameter. Index Terms: Bandpass filter, cross-coupling, microstrip filter, hairpin resonator.

Theory and Demonstration of Narrowband Bent Hairpin Filters Integrated With AC-Coupled Plasma Limiter Elements

A novel narrowband filter with integral high-power microwave limiter behavior is proposed to protect cost-sensitive microwave systems. The filter-limiter consists of a third-order microstrip bent hairpin filter with encapsulated gas plasma limiters, designed for operation at 870 MHz. An equivalent circuit model is presented for the ac-coupled plasma-shell components used in this study, and parameter values were extracted from measured results and electromagnetic simulation. The theory of operation of the proposed filter-limiter was experimentally validated and key predictions were demonstrated including two modes of operation in the on-state: a constant output power mode and constant attenuation mode at relatively higher power. The filter-limiter operates passively from incident microwave energy, and can also use an external priming voltage source to reduce the limiter turn-on power threshold and reduce output power variation during limiting.

Optimum Design of Novel UWB Multilayer Microstrip Hairpin Filters with Harmonic Suppression and Impedance Matching

Optimum design of a novel ultra-wideband multilayer microstrip hairpin filter is presented, providing for harmonic suppression and impedance matching between source and load impedances. The theory of N-coupled transmission lines is employed to obtain an equivalent circuit for development of a design procedure based on the method of least squares. A prototype model of proposed two-layer filter of order 5 is fabricated for 3.1–10.6 GHz. The dimensions of designed filter are 23 mm × 7 mm. The insertion loss in the passband varies from 0.3 dB to 3 dB (in the worst case at the edge of passband) and in the stopband is about 30 dB up to 20 GHz. Its group delay in the UWB region is about 0.5 ns. Close agreement among the filter frequency responses as obtained by the proposed method, full-wave computer simulation softwares, and measurement data verify the effectiveness of the proposed filter structure and design methods.

Reliability of Suspended Bridges on Superconducting Microstrip Filters Using MEMS Switches

This work proposes to use capacitive micro-electro-mechanical systems (MEMS) switches built on a superconducting microstrip hairpin filter to investigate the reliability of MEMS for long term survivability. This device is made of a YBa <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Cu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sub> thin film deposited on a 20 mm × 20 mm LaAlO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> substrate by pulsed laser deposition and BaTiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> by RF magnetron sputtering, which is utilized as a dielectric insulation layer at the switching points of contact. The major concern for capacitive MEMS switches is stiction between the gold suspended bridge membrane (top layer) and the dielectric material (bottom layer). The main failure mode results from charge build-up at the bottom layer which in turn depends on the actuation voltage. The actuation voltage measured at room and cryogenic temperature is used to derive and calculate the Young's modulus formula which takes into consideration the device geometry, residual stress and mechanical properties of the device. Modified Young's modulus equation will be validated through reliability data of membrane actuation and failure mode. This equation will in turn be used in modeling other RF MEMS devices operating at cryogenic temperatures.

TSV Technology for Millimeter-Wave and Terahertz Design and Applications

The through silicon via (TSV) technology provides a promising option to realize a compact millimeter-wave (mmW) and terahertz (THz) system with high performance. As the fundamental elements in this system, transmission lines (T-lines) and interconnects are very important and therefore studied in this paper. A TSV-based substrate integrated waveguide (SIW) is also characterized. The results show that, the T-lines and interconnects are viable at frequencies lower than ~150 GHz whereas SIW can operate relatively well up to 300 GHz. In addition, two mmW components, i.e., a hairpin filter and a patch antenna, are designed by the TSV technology. Results of all the above passive components indicate that the low-resistivity silicon is the main cause of the total loss. Afterwards, two novel TSV-based topologies are proposed to efficiently integrate an antenna with active circuits for the mmW and THz applications.

Design of a Compact Hairpin Filter with Spurious Suppression

In this paper, a new method for suppressing the first spurious passband in microstrip hairpin filter is proposed. For this purpose, meandered shaped coupled lines are used instead of conventional coupled lines. Furthermore, by using this method, a size reduction of 50% is achieved. Simulated and measured results show that the modified bandpass hairpin filter presents a rejection level exceeding 35 dB in the first spurious passband.

Harmonics blocking in hairpin filter using Defected Microstrip Structure

In this paper, it is demonstrated that the first and second spurious passbands suppression in microstrip hairpin filters can be achieved by simply patterning appropriate geometries of several Defected Microstrip Structure (DMS) in parallel coupled sections. By properly tuning DMS resonator dimensions, multiple transmission zeros can be generated in the vicinity of spurious harmonics and a wide stopband can be obtained. Experimental results verify that 25dB and 40dB suppression for the first and the second harmonics, respectively, without affecting the main passband response.

저지 대역 제거 특성을 향상시킨 변형된 헤어핀 여파기

본 논문에서는 원하지 않는 특정 주파수 신호의 감쇠 특성을 향상시키기 위한 새로운 헤어핀 구조 스트립 선로 대역 통과 여파기를 소개한다. 변형된 헤어핀 여파기는 전통적인 헤어핀 여파기의 설계 방식과 동일하게 설계하며, 설계된 여파기의 구조를 새롭게 배치함으로써 구현한다. 그리고 변형된 대칭 구조 사이에 새롭게 형성된 결합 선로의 영향들이 대역 통과 여파기의 상/하향 주파수에 전송 제로를 만든다. 이들 각각의 전송 제로들은 여파기의 특정 부분을 조절하여 원하는 특정 주파수에 위치시킬 수 있다. 이 새로운 여파기의 성능을 평가하기 위해 9.2 GHz에서 15 % FBW를 가지는 5차 Chebyshev 대역 통과 여파기를 제작하였다. 설계 후 측정 결과, 삽입 손실이 0.8 dB@9.2 GHz이며, 최대 50 dB 정도의 우수한 차단 특성을 나타내었다. In this paper, a new hairpin type strip-line BPF(Band Pass Filter) improving the suppression performance of unwanted frequency signal is studied. A modified hairpin filter is designed by classical hairpin filter design methodology and is realized by newly placing structure of designed filter. And a newly formed coupled-line effects between modified bilateral symmetry structures make the transmission zeros. Each transmission zeros can shift its frequency to wanted frequency by tuning a certain part of filter. To investigate the validity of this novel technique, an order-5 Chebyshev BPF centered at 9.2 GHz with a 15 % FBW(fractional bandwidth) were used. According to design and measurement results, a good performance of insertion loss of 0.8 dB and unwanted signal suppression of maximum 50 dB is achieved at full input/output ports.

Characterization and dielectric behavior of V 2O 5-doped 0.9Mg 0.95Co 0.05TiO 3–0.1Ca 0.6La 0.8/3TiO 3 ceramic system at microwave frequency

The microwave dielectric properties and the microstructures of Mg 0.95Co 0.05TiO 3–Ca 0.6La 0.8/3TiO 3 ceramics, prepared by a mixed oxide route, have been investigated. With small amount of V 2O 5 additions, the sintering temperatures of 0.9Mg 0.95Co 0.05TiO 3–0.1Ca 0.6La 0.8/3TiO 3 ceramics can be lowered to 1250 °C. The microwave dielectric properties are found strongly correlated with the sintering temperature as well as the amount of V 2O 5 additions. The Q × f value of 0.9Mg 0.95Co 0.05TiO 3–0.1Ca 0.6La 0.8/3TiO 3 increased with increasing temperature to 1250 °C and decreased thereafter. The decrease in Q × f value was coincident with the abnormal grain growth. A maximum Q × f value of 58,000 (GHz) associated with a dielectric constant ( ɛ r) of 21.7 and a temperature coefficient ( τ f ) of −10 ppm/°C, was achieved for 0.25 wt.% V 2O 5-doped samples at 1250 °C. Moreover, a cross-coupled compact hairpin filter with designed center frequency of 2.0 GHz is designed and fabricated using the proposed dielectric ceramic to study its performance. It also showed a substantial reduction in both insertion loss and size in comparison with other dielectrics FR4 and alumina.

개별 공진기의 EM 시뮬레이션에 기초한 새로운 직접결합 대역여파기 설계 방법

이상적인 전송선을 가정하고 도출된 여파기 설계 공식에 의하여 대역여파기를 설계할 경우, 제작된 여파기는 중심 주파수의 이동 및 주파수 특성의 왜곡을 발생시키며, 주파수가 높아질수록 심각한 문제를 야기한다. 이를 해결하기 위하여 본 논문에서는 개별 공진기의 EM(Electro-Magnetic) 시뮬레이션을 기초로 한 새로운 여파기 설계 방법을 제안하였다. 이 방법은 여파기를 개별 공진기로 분리하고, EM 시뮬레이션을 통해 개별 공진기의 리액턴스(reactance) 기울기 및 인버터 상수와 같은 여파기 설계 파라미터를 추출한 후, 이것이 인버터와 리액턴스 기울기로 구성된 인버터-기준형 설계치와 같도록 조정하는 것이다. 이와 같이 조정된 공진기를 조합하여 구성된 여파기는 별도의 조정 없이 목적한 설계치를 만족하게 된다. EM 시뮬레이션 시 이미 선로의 분산(dispersion) 및 불연속(discontinuity) 효과를 고려하였기 때문에 더 이상의 조정이 필요 없으며, 이 방법은 인버터-기준형으로 환원되는 대부분의 여파기에 적용 가능하다. 본 논문에서는 5단 SIR 여파기를 예로 들어 여파기 설계의 전반적인 과정을 설명하였고, 평행결합선로 여파기(parallel coupled line filter) 및 hair-pin 여파기에 확장 적용한 예를 보여 이 방법의 타당성을 보였다. The BPF designed by the formula based on strip line shows the center frequency shift and distortion in filter response and this becomes more significant with higher frequency. In this paper, the novel design based on EM simulation is proposed. In the design, the filter is decomposed into individual resonators and, for each resonator, the reactance slope and the inverter values are measured and tuned to desired design values for a inverter BPF prototype. The filter composed with such resonators shows the desired filter response without further tuning. This is because possible effects of discontinuities and dispersion are included in the filter parameter extraction. The method can generally apply to all filters that can be transformed into inverter BPF prototype. The procedure is verified by designing a 5th-order SIR filter and quite general to adapt into the design of a parallel coupled line filter, and hair-pin filter.

Digital Radio Broadcasting Frequency Chebyshev CLF and HPF Designs Using ROGER 4003C

The development of the frequency bands in microwave range filter play an important role in many RF or microwave applications. Filters are two port networks used to control the frequency response in an RF or microwave system by allowing transmission at frequencies within the passband, and attenuation within stopband of the filter. This research project consists of the elementary principle of microwave theory, the elementary knowledge of microwave filter design as well as fabrication and performance evaluation of Chebychev bandpass filters. The purpose of the research project is to compare the characteristic performance of different microstrip filter designs i.e coupled line (CLF) and hair pin filters (HPF). The designs were fabricated on the same type of material i.e FR4. Insertion loss method has been used in the design to produce the parallel coupled quarter wavelength resonator filters. The compatible filter in this project was able to filter out the required frequency for Digital Radio Broadcasting in the range of 1.452 GHz to 1.492 GHz. The designs were implemented using Microwave Office 2003 (V6.01) simulation software. The two filter designs were fabricated based on the Chebychev filter. The Chebyshev response is more selective than the Butterworth response at the expense of the insertion loss and greater group delay. The filters were tested using Advantest R3767CG Network Analyser. The entire filter designs and the performance of the substrate were evaluated. It was found that the HPF has better performance compared with CLF design in terms of bandwidth, matching impedance and quality factor.

An Integrated Approach to RF Antenna-Filter Co-Design

In this letter, a co-designed antenna-filter is presented. The antenna-filter is composed of a microstrip patch antenna and a hairpin filter, both of which share the same ground plane to reduce the size. Instead of using the traditional 50-Omega interfaces, the impedance between the filter and antenna is optimized to improve the performance. The simulated and measured results have demonstrated that co-designed antenna-filter has a better bandwidth (4.7%, 4.064.26 GHz) and a larger gain (4.3 dBi) than the traditional version with 50-Omega interfaces impedance.

Two-Cavity Filter With Three Transmission Zeros

It is well known that an N-order coupling network with source-load coupling can realize a maximum number of transmission zeros equal to N. However, in the letter, by utilizing open-circuited stubs and increasing the velocity ratio, a novel two-pole hairpin filter can obtain three transmission zeros, which can improve selectivity in the lower stopband. The filter is analyzed extensively by using the relations between the types of coupled microstrip lines and transmission zeros of transfer response. Good agreement between measured and simulated data has been demonstrated.

Compact cross‐coupled hairpin filter design using ceramic substrates

AbstractCross‐coupled hairpin filter design using electrical‐coupling with asymmetric feed on ceramics was reported. The band‐pass filters are designed at center frequency of 2.0 (GHz) with bandwidth of 10%. In addition, this article presents an analytical technique for positioning the locations of two transmission zeros for a microstrip band‐pass filters. The band‐pass filter uses two resonators with two transmission zeros to obtain lower insertion loss than a conventional cross‐coupled microstrip filter. Also, by using high Q, high permittivity dielectric materials as substrates, the filters demonstrate high selectivity, compact size, and can be used in many wireless communication systems. A bandwidth of 10% with −0.75 dB insertion loss and −34 dB attenuation was achieved with chip size of 2.5 × 0.85 cm2. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1795–1800, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23505

Combining Coarse and Fine Models for Optimal Design

In this article we reviewed the implicit space mapping concept. We illustrated it using a simple tapped-line microstrip filter example. We demonstrated the robustness of our approach by performing an accurate design of a microstrip hairpin filter. A detailed and easy-to-follow design optimization procedure was provided and the Agilent ADS implementation of the algorithm was described. A good electromagnetically validated design in Sonnet em was obtained in a few fine model simulations. Implicit space mapping is a simple approach to combine a circuit-theory based CAD model and an EM simulator model to achieve fast and accurate optimal design and modeling.

Design and experimental investigation on novel microstrip band‐pass filters

AbstractTwo novel fifth order, 2.5‐GHz bandpass filters, with 4% bandwidths were designed and fabricated. The filters which are modified versions of the hairpin filter are designed empirically using the optimization feature in microwave simulation software. We found good agreement between the simulated and measured responses of these filters, validating the optimization design methodology. The original hairpin filter has also been fabricated, and it is shown that the novel filters have good performance in comparison. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 655–658, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23152

Design, simulation, and fabrication of a MEMs switched superconducting microstrip hairpin filter

High performance high T c superconductor based series micro electromechanical system (MEMs) switches have been utilized to switch between a bandpass hairpin filter, center frequency f 0 = 2.5 GHz, and BW of 250 MHz, and a through transmission line. This was accomplished with four switches actuated in pairs, one pair at a time. When the first pair is actuated, the through transmission line is capacitively connected between the input and output ports; accordingly, the system behaves as a throughline. When the second pair of switches is actuated, the bandpass filter is coupled to the input and output ports; thus a corresponding bandpass response is obtained. The design is implemented on a YBa 2Cu 3O 7 thin film deposited on a 15 mm × 15 mm LaAlO 3 substrate by pulsed laser deposition. BaTiO 3 deposited by RF magnetron sputtering is utilized as the insulation layer at the switching points of contact. The advantages and issues of this structure and its fabrication details are discussed along with simulations and experimental data.

A Compact Dual-Frequency Rectifying Antenna With High-Orders Harmonic-Rejection

This paper proposes a novel dual-frequency rectifying antenna operating at 2.45 and 5.8 GHz. The rectifying antenna consists of two compact ring slot antennas, a hairpin lowpass filter, and a rectifying circuit. The annual slot ring antenna uses a meander line structure to reduce its size to 52% of the regular ring slot antenna. The hairpin filter helps suppress the second order and the third order harmonics of both operation frequencies. The dual-frequency rectifying antenna (rectenna) achieves RF-to-dc conversion efficiencies of 65% and 46% at 2.45 and 5.8 GHz, respectively, while the power density is 10 mW/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The rectenna is the smallest dual-frequency rectenna ever reported.

Fabrication of Three-Pole ${\rm HgBa}_{2}{\rm CaCu}_{2}{\rm O}_{6+\delta}$ Hairpin Filter and Characterization of Its Third Order Intermodulation

The increased research interest in the microwave applications of high temperature superconductors (HTS) was brought about by the perceived potential on the marketability of superconducting electronics, especially in the wireless communications industry. Excellent surface morphology and high reproducibility of the HgBa <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> CaCu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6+delta</sub> (Hg-1212) thin films made from cation exchange process has motivated us to develop microwave bandpass filters, which can be operated at above 77 K and therefore are much more cost effective. An Hg-1212 three-pole hairpin filter of 5% 3-dB bandwidth has been fabricated and characterized. The transmission properties and third-order inter modulation (IM3) measurements on the filter have demonstrated Hg-1212 as a promising alternative material for passive microwave devices at above 77 K operating temperature.

Design and Fabrication of Two Switch Superconducting Microstrip Hairpin Filters Using Series MEMS Switches

A superconductor circuit based on series Micro- Electro-Mechanical (MEM) switches is utilized to switch between two bandpass hairpin filters with 200 MHz bandwidth and nominal center frequencies of 2.1 GHz and 2.6 GHz. This is accomplished using 4 switches actuated in pairs, one pair at a time. When one pair is actuated the first bandpass filter is coupled to the input and output ports. When the other pair is actuated the second bandpass filter is coupled to the input and output ports, thus corresponding output responses are obtained. The device is made of YBa2Cu3O7 thin film deposited on a 20 mm times 20 mm LaAlO3 substrate by pulsed laser deposition. BaTiO3 deposited by RF magnetron sputtering is utilized as the insulation layer at the switching points of contact. Fabrication details are discussed along with simulation data and test results.