Compact microstrip stepped impedance wideband bandpass filter

A novel wideband bandpass filter with a very compact size is presented in this article. Using a side-coupled stepped impedance resonator, wideband characteristics with adjustable centre frequency and 3-dB fractional bandwidth can be obtained easily. Finally, a filter sample is designed and fabricated to provide an experimental verification on the proposed topology. Good insertion/return losses, flat group delay, wide bandwidth as well as ultra compact size are achieved as demonstrated in both simulation and experiment, which makes this filter a very promising candidate for applications in future wideband communication system.     

Compact wideband bandpass filter using quad mode resonator

This paper presents a compact wideband bandpass filter for TETRA band applications. The proposed filter design is based on a quad mode resonator designed using small rectangular loop loaded with four Stepped Impedance Stubs (SISs) and a short circuit stub. The four modes of the resonator help in generating a wide passband. The use of SISs makes the filter compact. In addition to four transmission poles, the resonator inherently generates a transmission zero above the higher end of passband. Two transmission zeros are generated by the input/output coupling which helps in increasing the selectivity and also for achieving wide stopband. This filter provides a 3 dB fractional bandwidth of 30.33% and maximum insertion loss of 1.3 dB at the center frequency 0.36 GHz with a compact size of 0.125 λ_g × 0.085 λg (4.1 × 2.78 cm²).     

Compact tri‐wideband bandpass filter with multiple transmission zeros

This paper presents a tri‐wideband bandpass filter (TWB‐BPF) with compact size, high band‐to‐band isolation, and multiple transmission zeros (TZs). The proposed TWB‐BPF is based on a multiple‐mode resonator (MMR), which is interpreted by the method of the even‐ and odd‐mode analysis technique. The MMR can excite 11 resonant modes, where the first two modes comprise the first passband, the next four modes form the second passband, and the last five modes are used to generate the third passband. In addition, 10 TZs are yielded to obtain high band‐to‐band isolation and wide stopband suppression characteristics up to 14.95f_c1 (f_c1 is the center frequency of the first passband). To verify the proposed filter, a TWB‐BPF with 3‐dB fractional bandwidths (FBWs) of 37.4%, 43.5%, and 40.4% is designed, fabricated, and measured.     

结构紧凑的高选择性宽带滤波器

摘 要：为实现结构紧凑和高选择性的宽带滤波器,在传统平行耦合线结构的基础上,作了适当改进,设计了三种结构新颖的三线耦合结构,均能够实现具有三个传输零点的宽带响应,且其中两个零点分别紧靠通带的上下边缘。加工并测试了基于其中一种结构的宽带滤波器,工作频率为2.6GHz,3dB相对带宽为63%,三个传输零点分别位于1.46GHz,3.77GHz和5.13GHz,介质基板采用Rogers 4003,厚度0.813mm。实测结果与仿真结果吻合良好,验证了结构的有效性。     

Compact, well-tuned bandpass filter

A compact, low power bandpass filter with additional tuning capability over previous bandpass filters is presented. Implemented in an analogue CMOS process, the n-well (bulk) conductance of the amplifiers in the filter is used to control both the resonant (peak) frequency and the Q factor of the filter frequency response. This technique is demonstrated to decrease the peak frequency while improving (sharpening) the Q factor. However, this same technique can be used to increase the peak frequency while improving the Q factor or to control the Q factor and peak frequency independently     

一种新型的HMSIW宽带带通滤波器

提出一种基于半模基片集成波导和缺陷地结构的新型宽带带通滤波器,将半模基片集成波导的高通特性与改进的哑铃形缺陷地结构的低通特性结合,实现了一种宽带小型化的带通滤波器。仿真与测试结果表明,该滤波器中心频率为5.3 GHz,相对带宽为53%,通带范围内插入损耗小于1.6 dB。该滤波器具有宽带小型化,容易集成等优点。     

一个紧凑型超宽带微带带通滤波器

设计制作了一种紧凑型超宽带微带带通滤波器。该滤波器采用两对由1/4波长型SIR谐振器和1/4波长终端短路谐振器构成的枝节线对与微带低通滤波器相联而成。在ADS软件上对该滤波器进行仿真验证,然后制作实物。结果表明,该滤波器相对带宽达到112%,阻带带宽超过4 GHz,通带范围内插入损耗小于1 d B,回波损耗大于10 d B,阻带范围回波损耗大于20 d B;滤波器尺寸为14.22 mm×9.65 mm。     

Compact and wideband microstrip bandstop filter

A novel one-section bandstop filter (BSF), which possesses the characteristics of compact size, wide bandwidth, and low insertion loss is proposed and fabricated. This bandstop filter was constructed by using single quarter-wavelength resonator with one section of anti-coupled lines with short circuits at one end. The attenuation-pole characteristics of this type of bandstop filters are investigated through TEM transmission-line model. Design procedures are clearly presented. The 3-dB bandwidth of the first stopband and insertion loss of the first passband of this BSF is from 2.3 GHz to 9.5 GHz and below 0.3 dB, respectively. There is good agreement between the simulated and experimental results.     

Compact membrane-supported bandpass filter for millimetre-wave applications

The design and testing of a new configuration of micromachined bandpass filter for millimetre-wave applications is presented. The design is based on image parameter representation of identical symmetrical cells connected in cascade. The measurements demonstrate transmission losses lower than 1 dB and very good agreement with the electromagnetic simulations.     

New compact wideband bandpass filter using three parallel-coupledlines

A new miniature bandpass filter, comprising three-conductor short-circuited spurline resonators of approximately a quarter-wavelength long, with a very wide bandwidth approaching multioctaves is reported for the first time. The chain matrix of the filter resonator is derived. The new filter has been developed using microstrip line with less than 1 dB insertion loss over a passband from 2 to 8 GHz. Reasonably good agreement between the measured and calculated results is observed     

Compact ultra-wideband bandpass filter using stub-loaded resonator

A compact filter for ultra-wideband (UWB) applications is proposed and developed through quasi-equal allocation of the first three resonant frequencies of a stub-loaded resonator together with strong input/output excitation. Measured results show low insertion loss and flat group delay in the entire passband as well as a wide stopband. The size for this single-layer UWB filter without feeding lines is only 9.5times5 mm (0.53 lambda_gtimes0.28 lambda_g in which lambda_g is the guided wavelength of 50 microstrip at the centre frequency).     

Compact dual-band microstrip bandpass filter without external feeds

A compact dual-band microstrip bandpass filter is proposed and designed to operate at 2.4 and 5.2GHz without needing any external impedance-matching block. The modified half-wavelength stepped-impedance resonator with sinuous configuration is constructed to simultaneously excite the dual resonances at these two specified frequencies with miniaturized overall size. The parallel-coupled microstrip line is properly characterized to minimize the return losses within both dual passbands. The optimized results exhibit the good dual-band filtering performances with return losses higher than 20dB as well being confirmed by experimentation with a fabricated filter circuit.     

Compact ultra-wideband bandpass filter using harmonic-suppressed multiple-mode resonator

A compact ultra-wideband bandpass filter with good upper-stopband performance is presented. A wide stopband above the desired passband is realised relying on three transmission zeros of capacitive-ended parallel coupled lines. A modified multiple-mode resonator is formed with a self-contained stopband. By linking this resonator with two interdigital coupled lines, an ultra-wideband bandpass filter is constituted. Predicted results are verified by experiment in a frequency range of DC to 25 GHz.     

Compact microstrip bandpass filter with sharp transition bands

The design of a two-pole compact microstrip bandpass filter is presented. The filter consists of only one miniaturized center-stubbed half-wavelength resonator and tapped-line input/output ports, and exhibits transmission zeros at both sides of the passband. Therefore, it is very compact, and provides sharp transition bands. The measurement results of filters designed at 4.4GHz are given to validate the theory.     

Compact UWB bandpass filter with improved upper-stopband performance

a compact microstrip-line ultra-wideband (UWB) bandpass filter (BPF) using aperture-backed interdigital coupled lines and a stub-loaded folded stepped-impedance resonator (SLFSIR) is presented. in the design, the first four resonant frequencies of this SLFSIR are properly adjusted to be placed evenly within the UWB while the fifth resonant frequency is raised above 16.0 GHz to improve upper-stopband performance. furthermore, the aperture-backed interdigital coupled lines can create a transmission zero to cancel the fifth resonant mode of the SLFSIR to make a wider upper-stopband as well as raising the coupling degree to relax the tight line spacing. after optimisation of this filter, good UWB bandpass behaviour is theoretically realised and experimentally confirmed.     

Compact resonant bandpass filter based on PBG structure

A new resonant bandpass filter based on a photonic band gap (PBG) structure is designed and optimised. The finite-difference time-domain method is applied to characterise the proposed filter. The filter is much easier to fabricate, more compact and simpler to design than the conventional parallel-coupled line filter, has wide stopband and steep and deep upper bandstop. The filter length is about one guiding wavelength (/spl lambda/e). A semiconductor-based structure is realised using microelectronics technology and good agreement between the experimental and simulation results has been achieved.     

Compact microstrip bandpass filter with two transmission zeros

A novel compact microstrip bandpass filter is proposed using a half-wavelength (/spl lambda//2) microstrip line resonator and an end-coupling resonator. The filter has two transmission zeros at both low and high rejection bands, as well as low insertion loss and compact design by giving two paths to the input signals. A demonstration filter has been designed and tested. Theoretical and experimental results are presented.     

一种小型化微波宽带带通滤波器及其工程设计

介绍了一种基于基片集成波导(SIW)结构的小型化微波宽带带通滤波器,采用紧凑型设计,同时提出了其工程设计方法及流程,通过11GHz和15GHz典型微波频段的四腔带通滤波器实例验证,达到对于偏离中心2GHz以上的频段抑制35dB以上的要求,且仿真与测试结果相对吻合较好,设计方法和流程合理、有效。本文网络版地址：http：//www.eepw. com.cn/article/271650.htm     

New compact ultra wideband bandpass filter using modified multi-mode resonator

A new compact ultra wideband (UWB) bandpass filter (BPF) using modified multi-mode resonator (MMR) is presented. The filter consists of a multi-mode resonator with dual spur-lines for providing the dual notch bands at 5.2 and 5.8 GHz and connected with a stepped impedance structure for controlling the transmission zeros at lower and higher passband edge. The interdigital coupling input/output (I/O) lines are used for coupling enhancement. The |S₂₁|-magnitude and the frequencies of notch bands can be well determined by tuning the dimensions of the dual spur-lines. The designed procedures are discussed and good agreement between the measurement and EM simulation are compared.     

Compact two-order bandpass filter with three finite zero points

A novel two-order bandpass filter (BPF) is proposed. The parallel coupling paths as well as similar zero point generation mechanism for the fundamental frequency and the first spurious frequency give the filter three controllable finite zero points in the stopband without adding any extra elements. Good skirt selectivity and controllable stopband characteristics can be achieved simultaneously.