Wideband Bandpass Filter With Reconfigurable Bandwidth

this letter proposes a novel building block for developing tunable wideband bandpass filters. The proposed circuit block mainly consists of short circuit coupled lines and short circuit stubs with pin diodes as tuning elements. This work aims to demonstrate reconfigurable bandwidth of this type of filter. Two filters are designed and fabricated; one can be switched between a fractional bandwidth (FBW) of 16.3% and 35% at a center frequency of 1.9 GHz, and the other can be switched from a FBW of 27.8% to 37.4% at a center frequency of 1.9 GHz. The insertion loss and return loss in the first filter range from 4.17 dB to 0.4 dB and 27.54 dB to 19.04 dB. The second filter exhibits an insertion loss ranging from 0.73 dB to 0.43 dB and a return loss range from 31.1 dB to 27.7 dB. The tested filters show good agreement with EM simulations.      

基于MMIC工艺的片上射频LC无源滤波器

设计、制作了几种基于MMIC工艺的片上LC低通/带通滤波器并进行了测试. 测试结果表明,一个3nH的MMIC电感在6.8GHz下品质因数达到13.8,自谐振频率达到15.5GHz;制作的LC低通/带通滤波器的截止频率或中心频率与设计偏差很小,分别为2%和3.3%;低通滤波器在各自通带内的插入损耗小于3dB,带通滤波器在中心频率的插入损耗为7.2dB.     

L波段双层交指线性相位MEMS滤波器的设计

针对射频MEMS滤波器的带外抑制能力较差和带内群延时不平坦的问题,设计了一种窄带宽、低插损、高选择性的L波段射频MEMS线性相位滤波器.选取高介电常数的衬底材料实现窄带传输,采用双层交指结构的谐振器实现线性相位,减小了电路体积.利用HFSS软件对滤波器的性能进行优化.结果表明,该滤波器的中心频率为1.46 GHz,带内...     

Low-loss LTCC cavity filters using system-on-package technology at 60 GHz

In this paper, three-dimensional (3-D) integrated cavity resonators and filters consisting of via walls are demonstrated as a system-on-package compact solution for RF front-end modules at 60 GHz using low-temperature cofired ceramic (LTCC) technology. Slot excitation with a /spl lambda/g/4 open stub has been applied and evaluated in terms of experimental performance and fabrication accuracy and simplicity. The strongly coupled cavity resonator provides an insertion loss <0.84 dB, a return loss >20.6 dB over the passband (/spl sim/0.89 GHz), and a 3-dB bandwidth of approximately 1.5% (/spl sim/0.89 GHz), as well as a simple fabrication of the feeding structure (since it does not require to drill vias to implement the feeding structure). The design has been utilized to develop a 3-D low-loss three-pole bandpass filter for 60-GHz wireless local area network narrow-band (/spl sim/1 GHz) applications. This is the first demonstration entirely authenticated by measurement data for 60-GHz 3-D LTCC cavity filters. This filter exhibits an insertion loss of 2.14 dB at the center frequency of 58.7 GHz, a rejection >16.4 dB over the passband, and a 3-dB bandwidth approximately 1.38% (/spl sim/0.9 GHz).     

A Fully Embedded LTCC Multilayer BPF for 3-D Integration of 40-GHz Radio

This paper demonstrates a low loss fully embedded multilayer bandpass filter (BPF) using low-temperature cofired ceramic (LTCC) technology for 3-D integration of 40-GHz multimedia wireless system (MWS) radio. The LTCC filter implemented in a stripline configuration occupies an area of only 5.5 times 2.3 times 0.6 mm including shielding structure and coplanar waveguide (CPW) transitions. The measured insertion loss was as small as 1.9 dB at a center frequency of 41.8 GHz, and the return loss was 12.2 dB including the loss associated with two CPW-to-stripline transitions. This six-layer BPF showed 3-dB bandwidth of 10.5% from 39.6 to 44.0 GHz at a center frequency of 41.8 GHz and suppressed the local oscillator (LO) signal to 20.2 dB at a local oscillator frequency of 38.8 GHz, making it suitable for the 40 GHz MWS applications.     

Millimeter-wave tune-all bandpass filters

Distributed microelectromechanical varactors on a coplanar waveguide have been used to design a two- and four-pole bandpass tune-all filters. The two-pole initial bandwidth is 6.4% at 44.05 GHz with a mid-band insertion loss of 3.2 dB and with matching better than 15 dB. The four-pole initial bandwidth is 6.1% at 43.25 GHz with a mid-band insertion loss of 6.5 dB and with matching better than 10 dB. The use of microelectromechanical system bridges allows a continuous tuning for both center frequency and bandwidth. The varactors biasing network has been designed so that the center frequency and bandwidth can be tuned separately. The two-pole filter center frequency can be changed from 44.05 to 41.55 GHz (5.6% tuning range), while the bandwidth can be independently changed from 2.8 to 2.05 GHz. The four-pole filter center frequency can be changed from 43.25 to 40.95 GHz (5.3% tuning range) and the bandwidth can be changed from 2.65 to 1.9 GHz.     

微型化Ka波段环形带线谐振腔LTCC带通滤波器

提出了一种微型化Ka频段带线带通滤波器设计方案.采用带有调谐枝节的环形谐振腔和带线耦合结构,利用低温共烧陶瓷(LTCC)技术设计并研制了一个相对带宽约10.4%的Ka频段带通滤波器,典型性能为在中心频率26.99 GHz处插入损耗小于1.3 dB,带内驻波比小于1.20:1,损耗起伏小于0.30 dB,滤波器的尺寸为4...     

基于SIW技术的毫米波滤波器研究与设计

基于基片集成波导（substrate integrated waveguide,SIW）结构设计了两款四阶的耦合带通滤波器,使用三维全波电磁场仿真软件HFSS对设计的两款滤波器进行了仿真设计和优化.由仿真结果分析得出,两款滤波器的工作频率均位于毫米波频段.第一款SIW滤波器实现了切比雪夫型响应,中心频率为20 GHz,带宽为2 GHz,通带内的插入损耗低于1.5 dB,回波损耗低于-20 dB,在阻带中对信号的衰减程度可以达到50 dB.第二款SIW滤波器实现了准椭圆函数型的响应,中心频率为29.1 GHz,带宽为300 MHz,通带内的插入损耗低于1 dB,回波损耗低于-20 dB,在通带到阻带的过渡中实现了两个陷波点.仿真结果表明,在毫米波滤波器设计中引入SIW结构,有利于优化滤波器尺寸,得到较好的滤波器性能指标,是毫米波滤波器发展的一个重要方向.     

Design of Nonradiative Dielectric Waveguide Filters (Short Papers)

An efficient design technique of nonradiative dielectric waveguide filters for use at millimeter wavelengths is developed. Filter stuctures considered here are a gap-coupled type and an altenating-width type. According to present theory, 3-pole, 0.1-dB Chebyshev ripple bandpass filters with a 2-percent bandwidth at a center frequency of 49.5 GHz were designed and fabricated with Teflon dielectric. Calculated and measured filter responses agree quite well, and excess insertion losses are found to be as small as 0.3 dB for both types of the fabricated filter circuits.     

A 60-GHz Millimeter-Wave Bandpass Filter Using 0.18-μm CMOS Technology

This letter presents the design and implementation of a 60-GHz millimeter-wave RF-integrated-circuit-on-chip bandpass filter using a 0.18-mum standard CMOS process. A planar ring resonator structure with dual-transmission zeros was adopted in the design of this CMOS filter. The die size of the chip is 1.148times1.49 mm². The investigations of sensitivity to the insertion loss and the passband bandwidth for different perturbation stub sizes are also studied. The filter has a 3-dB bandwidth of about 12 GHz at the center frequency of 64 GHz. The measured insertion loss of the passband is about 4.9 dB, and the return loss is better than 10 dB within the passband.     

Compact frequency and bandwidth tunable stopband filters using split ring resonators and varactors coupled transmission line

Two highly compact tunable stopband filters using microstrip transmission lines coupled with split ring resonators (SRRs) and varactor diodes are presented. Frequency or bandwidth tuning capability of each device is demonstrated. The frequency tunable filter, realized by a single stage, shows a wide tuning range of 19.8% with a maximum bandwidth of 5% and an insertion loss of approximately 20 dB at 4 GHz. The bandwidth tunable filter, realized by double stages, shows a 10-dB bandwidth of 19–34% with a biasing voltage of 0–10 V. The implemented frequency tuning and bandwidth tuning devices show a significant area reduction of 60.1% and 53.5%, respectively, in comparison with a similar frequency or bandwidth tunable structure presented by others. Equivalent circuit models are presented. The measured S-parameters are in good agreement with simulated ones.     

Active GaAs MMIC band-pass filters with automatic frequency tuningand insertion loss control

This paper presents the design and measured performance of active tunable band-pass MMIC filters and matched MMIC control circuits, both fabricated using a standard 1-μm GaAs MESFET foundry process. The control circuits generate filter frequency-tuning and Q-control bias voltages by using a dual-loop master-slave control scheme. Separate 3-section filters cover 1.5-2.0 and 1.96-2.64-GHz bands with 3-dB bandwidths of 86±6 and 126±1.0 MHz, respectively. The control circuits automatically maintain the filter insertion loss to within ±0.5 dB over these tuning ranges, and regulate the center frequency and insertion loss to within better than ±1.2 MHz and ±0.3 dB over a temperature range of -50°C to +75°C     

A K-band bi-phase modulator MMIC for UWB application

A 24-GHz-band, three-dimensional microwave monolithic integrated circuit (MMIC) bi-phase modulator, that is a combination of an active 0//spl pi/ splitter and a SPDT switch, is proposed and demonstrated. Comparing conventional K-band bi-phase modulators, this modulator is broadband, significantly MMIC compatible, and shrinks its chip area. A fabricated bi-phase modulator exhibits an area of 1.0/spl times/0.7mm/sup 2/ and a 1-dB bandwidth of nearly 10GHz. The SPDT switch is optimized in control-gate's time constant so that a very clear bi-phase modulated waveform can be generated from 1Gbps PN code. The insertion loss and the phase imbalance are 6.4 dB+/-0.6 dB and within 10/spl deg/, respectively, between 22GHz and 32GHz.     

HTS coplanar meander-line resonator filters with a suppressed slot-line mode

The design and experimental results of a four-pole coplanar waveguide (CPW) quasi-elliptic filter using high-temperature superconductor (HTS) films are presented. Quarter-wavelength meander-line resonators are used in the filter topology. Although the resonators are aligned in two lines, no bond-wire bridges are required to balance the ground planes in the design and measurement. The slot-line mode of the filter was shifted to be higher than its third harmonic. The filter is highly miniaturized and the performance is significantly improved by the use of superconductors. The main circuit of the filter only has an area of about 6.6 mm /spl times/ 2.4 mm on a magnesium oxide substrate, coated with 600-nm-thick YBCO HTS thin film on single side of the substrate. The 3-dB bandwidth is about 1.6% centered at 2.95 GHz. The performance measured at 30 K, without any tuning, gives an insertion loss of better than 0.4 dB and a return loss of about 12 dB in the passband. The first spurious mode is about triple the center frequency.     

A Fully Embedded 60-GHz Novel BPF for LTCC System-in-Package Applications

In this paper, a novel LTCC stripline (SL) 60-GHz band-pass filter (BPF) composed of transitions to coplanar waveguide (CPW) pads for monolithic microwave integrated circuit integration is presented. For low-loss interconnection with active devices, a CPW-to-SL vertical via transition integrating air cavities and a CPW-to-CPW planar transition using internal ground planes are proposed and implemented. The fabricated transition shows an insertion loss of 1.6 dB and a reflection loss below -20 dB at the passband of the filter. The implemented SL BPF using dual-mode patch resonators shows a center frequency of 60.4 GHz, 3.5 % bandwidth, and reflection losses below -15 dB at the passband. Excluding the insertion loss of the transitions, the filter insertion loss reveals 4.0 dB     

8-GHz Narrowband High-Temperature Superconducting Filter With High Selectivity and Flat Group Delay

This paper reports a development of a narrowband high-temperature superconducting filter with both high selectivity and flat group delay. The filter has a center frequency of 8.625 GHz and a 3-dB bandwidth of 42 MHz (a fractional bandwidth of 0.49%). In order to achieve both high band-edge steepness and excellent group-delay flatness, we introduce a 14-resonator quasi-elliptic function response with three pairs of transmission zeros (one pair for high selectivity and two pairs for flat group delay) in the cascaded quadruplet coupling structure. We also develop a novel low radiation resonator (double-folded resonator) to reduce the parasitic coupling and meet other requirements for the 8-GHz filter. The filter was fabricated on a 2-in-diameter 0.5-mm-thick MgO wafer with double-sided YBCO films. The measured results show a midband insertion loss of 1.6 dB and a return loss better than 15.5 dB. Band-edge steepness reaches over 11.7 dB/MHz at both the high- and low-frequency edges. The 60-dB rectangle ratio is less than 1.25. The out-of-band rejection is over 70 dB at 5.98 MHz from the 3-dB band edge. The variation of group delay is less than 23 ns over 33 MHz (78.5% of 3-dB bandwidth), and less than 30 ns over 34.5 MHz (82% of 3-dB bandwidth).      

An electronically tunable microstrip bandpass filter using thin-film Barium-Strontium-Titanate (BST) varactors

A tunable third-order combline bandpass filter using thin-film barium-strontium-titanate varactors and fabricated on a sapphire substrate is reported. Application of 0-200-V bias varied the center frequency of the filter from 2.44 to 2.88 GHz (16% tuning) while achieving a 1-dB bandwidth of 400 MHz. The insertion loss varied from 5.1 dB at zero bias to 3.3 dB at full bias, while the return loss exceeded 13 dB over the range. The third-order intercept of the filter was found to be 41 dBm.     

Multistage second-order microring-resonator filters with box-like spectral responses and relaxed fabrication tolerances

We demonstrate an optical filter based on multistage second-order microring resonators (MRs) with box-like spectral responses. Compared with single-stage high-order optical filters with the same number of MRs, the demonstrated structure has comparable performances in the aspects of passband flatness, rolling-off slope and insertion loss. Moreover, the architecture relaxes the fabrication tolerance, electrical wiring and tuning difficulty since there are only two MRs in each stage. We experimentally demonstrate this kind of optical filter with five stages, which shows a 3-dB bandwidth of ~17 GHz, a rolling-off slope of ~5 dB/GHz and an on-chip insertion loss of ~6 dB.     

345 GHz Band-Pass Filter Using Ultra-Precision Machining Technology

This paper presents a terahertz (THz) band-pass filter using ultra-precision machining technology based on Chebyshev filter prototype. This iris inductive window coupled waveguide filter was designed by using 8 resonant cavities with a center frequency of 345 GHz and a 7% bandwidth. The final design fulfills the desired specifications and presents the minimum insertion loss of 1.55 dB and the return loss of less than 15 dB at 345 GHz. The stop-band rejection is 50 dB off the center frequency about 30 GHz, which means it has a good performance of high stop-band suppression. Compared with the recent development of THz filters, this filter possesses the characteristic of simple structure and is easy to machining.     

InAlAs/InGaAs/InP基PHEMTs小信号建模及低噪声应用

利用改进的小信号模型对采用100nmInAlAs/InGaAs/InP工艺设计实现的PHEMTs器件进行建模, 并设计实现了一款W波段单片低噪声放大器进行信号模型的验证。为了进一步改善信号模型低频S参数拟合差的精度, 该小信号模型考虑了栅源和栅漏二极管微分电阻, 在等效电路拓扑中分别用Rfs和Rfd表示.为了验证模型的可行性, 基于该信号模型研制了W波段低噪声放大器单片.在片测试结果表明:最大小信号增益为14.4dB@92.5GHz, 3dB带宽为25GHz@85-110GHz.而且, 该放大器也表现出了良好的噪声特性, 在88GHz处噪声系数为4.1dB, 相关增益为13.8dB.与同频段其他芯片相比, 该放大器单片具有宽3dB带宽和高的单级增益.