共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
为了解决变容管电调窄带滤波器的插入损耗大和承受功率小的问题,研究了用压电换能器作电调元件的电调介质滤波器.分析了压电换能器调谐介质谐振器的机理,讨论了耦合系数和外部Q值的控制方法,仿真结果表明耦合系数和外部Q值随调谐频率的变化较小.采用HFSS软件设计和优化了两级电调介质滤波器的结构,并用高Q值的介质谐振器制作了两级电调介质滤波器.根据ANSYS软件的分析结果,提出了提高电调率的有效措施.当控制电压为0~50V时,滤波器的中心频率调谐范围为4.155~4.205GHz,3dB带宽为37~40MHz. 相似文献
3.
Hybrid Narrow-Band Tunable Bandpass Filter Based on Varactor Loaded Electromagnetic-Bandgap Coplanar Waveguides 总被引:1,自引:0,他引:1
《Microwave Theory and Techniques》2005,53(8):2506-2514
A varactor-loaded resonator inserted between two Bragg reflectors has been implemented to design high-selectivity tunable bandpass filters. First, a mechanical tuning method is demonstrated. A varactor tunable bandpass filter is then implemented at 9 GHz, yielding good agreement between computational and experimental results. The tuning range reaches 3.5% with a loaded quality factor$Q_L =40$ , a maximum insertion loss of 4.75 dB, and a return loss exceeding 20 dB. The theory is carefully explained, showing the importance of the parameters of the Bragg reflectors and of the resonator, in particular, the effect of diode-case parasitics and varactor position with respect to the resonator. A large-signal experimental analysis is done, showing a maximum allowable input power of a few dBm. Finally, possible filter improvements are discussed, and simulations with a microelectromechanical systems varactor are shown. 相似文献
4.
5.
描述了一种使用HTS/AuMEMS 开关电容器阵的低插损电子调谐式滤波器。同步将每个谐振器的电容值以相同变化量变化,两极滤波器就得到调谐。单极谐振器在3500~5000之间的K 系数得到了证明。在77K 平均Q 值为7000 时的总调谐范围大约为25%。 相似文献
6.
Tae-Yeoul Yun Kai Chang 《Microwave Theory and Techniques》2002,50(5):1303-1310
This paper introduces a new method to tune microwave circuits of phase shifters, filters, resonators, and oscillators, controlled by a piezoelectric transducer (PET) with computational and experimental results. An optimized PET-controlled phase shifter is demonstrated to operate up to 40 GHz with a maximum total loss of 4 dB and phase shift of 480°. PET-controlled tunable bandpass filter, ring resonator, and one-dimensional photonic-bandgap resonator show a very wide tuning bandwidth of 17.5%-28.5% near 10 GHz with little performance degradation. A new PET-controlled or voltage-controlled dielectric-resonator oscillator (DRO) is demonstrated with a tuning bandwidth of 3.7% at the center frequency of 11.78 GHz. The tuning bandwidth is slightly less than that of a mechanical tuning using a micrometer-head-controlled tunable DRO with a tuning bandwidth of 4.7%. The new tuning method should have many applications in monolithic and hybrid microwave integrated circuits 相似文献
7.
该文基于金丝键合工艺和薄膜工艺,实现了一种低插损、小型化毫米波调谐微带滤波器。首先提出了一种加载矩形孔的半波长开路可调谐振器,通过在不同矩形孔上键合金丝来改变谐振器的等效电感值,从而改变谐振频率。然后利用所提出的可调谐振器实现了一种Ka频段五阶调谐带通滤波器,通过改变键合金丝状态来调谐频率,实现仿真和实测结果之间的偏差修正,解决了在毫米波频段由于介电常数批次性差异以及加工误差等因素造成的窄带滤波器频率偏移的问题。为了验证其可行性,对五阶调谐微带滤波器进行仿真、优化、加工及测试。结果表明,该滤波器的通带可调范围为35.35~35.95 GHz,插入损耗小于4.6 dB,能够实现所需通带。 相似文献
8.
《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1967,55(10):1734-1735
This paper describes a low-loss tunable dielectric resonator band bandpass filter for the frequency range 1 to 12 GHz. The filters are mechanically and/or magnetically tuned. Mode splitting, due to coupling between dimensional dielectric resonances with ferrimagnetic modes, and heat sinking techniques significantly improve the power-handling capabilities. 相似文献
9.
A thermal and electromagnetic model of a tunable hybrid-mode dielectric double resonator is introduced and analyzed by the mode-matching technique. Results of the analysis show the temperature sensitivity of the structure as a function of the center frequency as well as the other resonator parameters. A simple optimization procedure which allows the design of the resonator to have both a wide tunability range and good thermal stability of the resonant frequency is described. A circuit model is presented for a tunable four-pole dual-mode filter. The model exhibits interesting dual passbands, separated by a very-high-attenuation stopband. Measured results obtained from an experimental four-pole dual-mode dielectric resonator filter designed using the tunable hybrid-mode resonators showed excellent tunability range (200 MHz at C -band) and good agreement with the circuit model 相似文献
10.
Entesari K. Obeidat K. Brown A.R. Rebeiz G.M. 《Microwave Theory and Techniques》2007,55(11):2399-2405
This paper presents a state-of-the-art discrete RF microelectromechanical systems (MEMS) tunable filter designed for 25-75-MHz operation. This paper also presents an enhanced model of the RF MEMS switch, which is used for accurate prediction of the tunable filter response. The two-pole lumped-element filter is based on digital capacitor banks with on-chip metal-contact RF MEMS switches and lumped inductors, and results in a tuning range of 3:1 with fine frequency resolution, and a return loss better than 13 dB for the entire tuning range. The relative bandwidth of the filter is 4 plusmn 1% over the tuning range and the insertion loss is 3-5 dB, limited mostly by the inductor Q and the switch loss. The IIP3 measurements prove that tunable filters with metal-contact series RF MEMS switches show extremely linear behavior (IIP3 > 68 dBm). 相似文献
11.
Stable single-mode compound-ring erbium-doped fiber laser 总被引:5,自引:0,他引:5
Jianluo Zhang Chao-Yu Yue Schinn G.W. Clements W.R.L. Lit J.W.Y. 《Lightwave Technology, Journal of》1996,14(1):104-109
In this paper we report the fabrication of a robust, tunable single-longitudinal-mode compound-ring Er3+-doped fiber laser. The laser is fundamentally structured on an all-fiber compound-ring resonator in which a dual-coupler fiber ring is inserted into the main cavity. When combined in tandem with a mode-restricting intracavity tunable bandpass filter, the compound-ring resonator ensures single-longitudinal-mode laser oscillation. The laser can provide up to 20 mW output power over much of its 1525 to 1570 nm wavelength tuning range. The short-term linewidth of the laser output measured is less than 5 kHz. The laser frequency is actively stabilized for a long time by exploiting the inherent filter nature of the compound-ring resonator. The reduction of an associated frequency modulation is also discussed in detail 相似文献
12.
Compact bandpass filters are being developed using Mobius wire-loaded cavity resonators. Initial results on tuned filters indicate that excellent filter characteristics can be attained in devices that are significantly smaller than traditional wire-loaded cavity technologies. A novel quad-mode Mobius resonator is presented which occupies the same volume as a dual-mode Mobius resonator. A four-pole bandpass filter is demonstrated using a single quad-mode Mobius resonator. Precisely controlled dielectric loading of dual-mode Mobius wire resonators has been implemented to realize bandpass filters. Two-pole and four-pole bandpass filters are demonstrated using one and two dual-mode dielectric-loaded Mobius resonators, respectively 相似文献
13.
A novel microstrip square-loop dual-mode bandpass filter with simultaneous size reduction and spurious response suppression 总被引:1,自引:0,他引:1
Si-Weng Fok Pedro Cheong Kam-Weng Tam Martins R.P. 《Microwave Theory and Techniques》2006,54(5):2033-2041
In this paper, a new capacitively stepped-impedance resonator(CSIR) is proposed to develop the microstrip square-loop dual-mode bandpass filter. Using this new design, simultaneous size reduction and spurious response suppression for the dual-mode bandpass filter can be achieved. An analytical formulation of this novel resonator is given in order to elucidate the spurious frequencies relocation design. Together with this formulation, a generalized dual-mode bandpass filter model is developed so as to ease the analysis of transmission zero and insertion loss. A prototype filter is designed at 900MHz with 1.5% fractional bandwidth. Significant spurious suppressions up to 33 and 35 dB are measured at 1.8 and at 2.7 GHz, respectively. A circuitry size reduction of 54% is achieved when compared with that of the conventional structure. Moreover, the CSIR allows frequency tuning and, thus, a varactor-tuned filter is designed and a measured tunable center frequency between 1.5-1.62GHz is demonstrated. Utilizing the proposed structure, not only size reduction,as well as spurious response suppression, but also center frequency tuning can be achieved. 相似文献
14.
Visocchi P. Taylor J. Mason R. Betts A. Haigh D. 《Solid-State Circuits, IEEE Journal of》1994,29(7):840-843
A second-order bandpass filter employing the operational transconductance amplifier-capacitor (OTA-C) method and featuring independent tuning of center frequency and Q is described. The filter, which is realized in 0.5-μm GaAs MESFET technology, is intended for use in high-precision, continuous-time (CT) IF bandpass filtering applications requiring both accurate amplitude and group delay responses. The filter center frequency is tunable in the range 12-50 MHz, Q is tunable in the range 4-60, and a transfer function accuracy of the order of 1% is achieved throughout the tuning range. Active area is 1 mm2 and static power consumption is 230 mW 相似文献
15.
Hong-Teuk Kim Jae-Hyoung Park Yong-Kweon Kim Youngwoo Kwon 《Microwave and Wireless Components Letters, IEEE》2002,12(11):432-434
This paper presents compact V-band MEMS-based analog tunable bandpass filters with improved tuning ranges and low losses. For compact size and wide tuning range, the two-pole filters are designed using the lumped-elements topology with metal-air-metal (MAM) bridge-type capacitors as tuning elements. Capacitive inter-resonator coupling has been employed to minimize the radiation loss, which is the main loss contributor at high frequencies. Two filters have been demonstrated at 50 and 65 GHz. The 65-GHz analog tunable filter showed a frequency tuning bandwidth of 10% (6.5 GHz) with low and flat insertion losses of 3.3 /spl plusmn/ 0.2 dB over the entire tuning range. 相似文献
16.
Kaunisto R. Reimann K. Boyle K. Krogerus J. Liu Z. Steeneken P.G. Ollikainen J. 《Electronics letters》2009,45(14):738
A programmable bandpass filter for 2.0?2.7 GHz centre frequencies and 450?500 MHz 3 dB bandwidth is presented. The filter is based on packaged RF-MEMS capacitor matrices as the tunable elements. The coupled-resonator filter topology was chosen with added transfer zeros. The results show excellent match between simulation and measurements. The measured insertion loss is 4.5?5.5 dB over the tuning range, and the linearity measurements show an OIP3 of 55? 64 dBm. 相似文献
17.
本文叙述采用梳状线结构的变容管电调微波带通滤波器的设计理论和方法。推导出梳状线带通滤波器的输入、输出耦合网络的参数条件,以补偿带通滤波器的谐振器之间电磁耦合随不同调谐频率的变化;并给出使带通滤波器的绝对带宽或通带回波损耗在调谐频率范围内变化最小时,梳状线谐振器的电长度应满足的相应条件,由此来保证电调带通滤波器在较宽的调谐频率范围内具有较高的通带回波损耗,且保持带通滤波器的响应形状和绝对带宽基本不变。此外,还讨论了由电调变容管的Q值引起的带通滤波器的通带有功损耗问题。文中给出了具体的设计公式。最后,给出了一个L波段变容管电调带通滤波器的研制实例和测试结果。 相似文献
18.
Miniature and tunable filters using MEMS capacitors 总被引:4,自引:0,他引:4
Microelectromechanical system (MEMS) bridge capacitors have been used to design miniature and tunable bandpass filters at 18-22 GHz. Using coplanar waveguide transmission lines on a quartz substrate (/spl epsiv//sub r/ = 3.8, tan/spl delta/ = 0.0002), a miniature three-pole filter was developed with 8.6% bandwidth based on high-Q MEMS bridge capacitors. The miniature filter is approximately 3.5 times smaller than the standard filter with a midband insertion loss of 2.9 dB at 21.1 GHz. The MEMS bridges in this design can also be used as varactors to tune the passband. Such a tunable filter was made on a glass substrate (/spl epsiv//sub r/ = 4.6, tan/spl delta/ = 0.006). Over a tuning range of 14% from 18.6 to 21.4 GHz, the miniature tunable filter has a fractional bandwidth of 7.5 /spl plusmn/ 0.2% and a midband insertion loss of 3.85-4.15 dB. The IIP/sub 3/ of the miniature-tunable filter is measured at 32 dBm for the difference frequency of 50 kHz. The IIP/sub 3/ increases to >50 dBm for difference frequencies greater than 150 kHz. Simple mechanical simulation with a maximum dc and ac (ramp) tuning voltages of 50 V indicates that the filter can tune at a conservative rate of 150-300 MHz//spl mu/s. 相似文献
19.
20.
《Microwave Theory and Techniques》2005,53(8):2566-2571
This paper presents a state-of-the-art RF microelectromechanical systems (MEMS) wide-band tunable filter designed for the 12–18-GHz frequency range. The coplanar-waveguide filter, fabricated on a glass substrate using loaded resonators with RF MEMS capacitive switches, results in a tuning range of 40% with very fine resolution, and return loss better than 10 dB for the whole tuning range. The relative bandwidth of the filter is$hbox5.7pm hbox0.4hbox%$ over the tuning range and the size of the filter is 8 mm$, times ,4$ mm. The insertion loss is 5.5 and 8.2 dB at 17.8 and 12.2 GHz, respectively, for a 2-$hboxkOmega/hboxsq$ bias line. The loss improves to 4.5 and 6.8 dB at 17.8 and 12.2 GHz, respectively, if the bias line resistance is increased to 20$hboxkOmega/hboxsq$ . The measured$ IIP_3$ level is$≫$ 37 dBm for$Delta f ≫ 200$ kHz. To our knowledge, this is the widest band planar tunable filter to date. 相似文献