首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 0 毫秒
1.
    
This article presents two novel resonators, that is, frequency selecting coupling structure loaded stepped‐impedance resonator (FSCSLSIR) and π‐section loaded FSCSLSIR. The resonator behaviors and guidelines are given to design FSCSLSIR dual‐band bandpass filter (BPF) and π‐section loaded FSCSLSIR triband BPF. The proposed dual‐ and triband BPF have very compact sizes of 0.13 λgd × 0.06 λgd and 0.115 λgt × 0.074 λgt, respectively. Moreover, good return loss, low insertion loss, and high band‐to‐band isolation can be observed, and the proposed FSCSLSIR dual‐band BPF has an ultrawide stopband from 5.79 to 36 GHz. The experimental results are in good agreement with the simulations. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:427–435, 2015.  相似文献   

2.
    
In this article, a compact dual‐band bandpass filter (BPF) is developed using a hybrid resonant structure, which consists of a microstrip stub‐loaded dual‐mode resonator and a slotline stub‐loaded dual‐mode resonator. These two resonators, both having two controllable resonant modes and one transmission zero (TZ), are analyzed and used to construct two desired passbands of a dual‐band BPF. Multiple TZs are generated by introducing a source‐load coupling, thus improving the selectivity of the passbands. Then, the dual‐band BPF is reshaped to configure a compact diplexer. The inherent TZs of the two proposed resonators are designed to improve the frequency property and port isolation of the diplexer. Finally, a dual‐band BPF and a diplexer with the lower and upper passbands centered at 2.45 and 3.45 GHz, respectively, are designed, fabricated, and measured to verify the proposed structure and method.  相似文献   

3.
    
In this study, a novel stepped impedance resonator (SIR) is proposed. This SIR is composed of two stepped impedance transmission‐lines and an interdigital capacitor structure. The proposed resonator has a high ratio of the first spurious frequency fs to the fundamental frequency f0 and is suitable to design wide stopband filters. An equivalent model is used to analyze the resonant properties of the resonator. The design guidelines of the proposed resonator are summarized. Moreover, the coupling properties of the resonator are simulated and analyzed. Finally, a small high‐temperature superconducting bandpass filter is designed and fabricated using the proposed SIRs. The stopband of the filter is extended up to 4.0 f0 and 3.5 f0 with 30 and 60 dB out‐of‐band rejection levels, respectively.  相似文献   

4.
    
A stepped‐impedance‐stub loaded stepped‐impedance resonator (SISLSIR) is proposed to design a dual‐band bandpass filter. The even‐ and odd‐mode frequencies and the coupling strength of the proposed resonators can be independently designed and adjusted. A dual‐feedline structure is used to meet the required external couplings of the 2 passbands. Thus, both the center frequencies and the bandwidths of the 2 passbands can be independently controlled. A 6‐pole dual‐band filter with the passbands of 3300～3600 MHz and 4800～5000 MHz is successfully designed using the proposed method and fabricated with YBCO/MgO high‐temperature superconducting (HTS) wafer. The measured results of the filter exhibit high performance and match well with the simulations. The measured insertion losses are less than 0.2/0.3 dB, and the return losses are greater than 15/14 dB for the lower/upper passbands, respectively. The out‐of‐band rejection is greater than 68 dB up to 12 GHz.  相似文献   

5.
    
A balanced second‐order dual‐band bandpass filter (BPF) with independently controllable center frequencies and bandwidths based on coupled stepped‐impedance resonators (SIRs) is designed in this article. To obtain a dual‐band differential‐mode (DM) response, two pairs of SIRs with different resonant frequencies are employed in the design. The bandwidths of the two DM passbands can be independently tuned by adjusting the coupling gaps and coupling lengths of the corresponding resonators. In addition, three transmission zeros are realized to enhance the selectivity of the DM passbands. The microstrip‐slotline transition structure is utilized to achieve a wideband common‐mode (CM) suppression. Moreover, the DM responses are independent of the CM ones, which significantly simplify the design procedure. Finally, a balanced dual‐band BPF is designed to validate the design method and a good agreement between the simulated and measured results is observed.  相似文献   

6.
    
In this article, a novel dual‐band differential bandpass filter using (SIRs) is designed. To demonstrate the design ideas, the differential and common mode equivalent half circuits are built and studied. Two resistors are connected between the two ends of the SIRs to consume the power in common mode. A capacitor is connected between the Ground and Center of the SIR to adjust the spurious frequencies, also strength the coupling of the two SIRs. The theoretical analysis shows the second band can be obtained by the proper impedance ratios of the resonances and the capacitor connected to the resonator. Two through ground vias (TGVs) connecting the top and bottom sides of the SIR filter, are used to realize the common mode rejection. To investigate the proposed filter in detail, a set of design equations are derived based on the circuit theory and transmission line theory. A phototype dual‐band differential filter operating at 1.5 and 2.75 GHz has been realized to validate the proposed concept and theory. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:468–473, 2015.  相似文献   

7.
    
Two novel dual‐band microstrip bandpass filters (BPFs) with multiple transmission zeros are proposed in this article. The dual‐band BPFs with second‐order bandpass responses are due to two λ/4 stepped‐impedance resonators (SIRs). Two passbands (center frequency ratio f s/f0 is 2.36) are realized based on the asymmetric SIRs. The transmission zeros near the passbands can be adjusted conveniently using the stopband transmission characteristic of the open/shorted coupled lines. Two planar microstrip dual‐band BPFs (ε r = 2.65, h = 0.5 mm) with four and six transmission zeros are designed and fabricated. High selectivity and good in‐band performances can be achieved in the proposed filters.  相似文献   

8.
    
A Compact Dual Band‐Bandpass Filter (DB‐BPF) with wide stopband rejection is proposed in this article. The basic tools used in the structure are Short Circuited Stepped Impedance Resonators (SCSIR), Open Stub Resonators (OSR). First, a Single Band‐Bandpass Filter (SB‐BPF) is designed with wide stopband rejection, and then it is modified to DB‐BPF. Both the SB‐BPF and DB‐BPFs have similar type of construction except for an additional SCSIRs used in DB filter. The structure of the filters, use the source‐load coupling and OSR to generate transmission zeros, which suppresses harmonics and achieves wide stopband. The use of SCSIRs make the SB and DB bandpass filters size compact to 0.099λg×0.094λg and 0.118λg×0.092λg, where λg is guided wavelength with a wide stopband upto 6.85f0 with 22 dB suppression for SB‐BPF and 2.78f1/7.57f0 with 22 dB suppression for DB‐BPF, where f0 and f1 are centre frequencies of first and second passbands respectively.  相似文献   

9.
    
Four‐stage stepped‐impedance resonator (FSSIR) is proposed and its resonant characteristics are analyzed in detail. The formulas of the first four resonances are deduced and the optimization techniques are presented on the basis of the impedance ratios. A quad‐band bandpass filter with third‐order filtering response in each passband is synthesized and designed as a demonstration of the application of the proposed FSSIR. Thanks to the cross‐coupling topology and skew‐symmetrical feeding configuration, multiple transmission zeros have been generated out of the passbands. Additionally, the frequency and the couplings of each passband can be flexibly controlled, respectively.  相似文献   

10.
    
In this study, we propose a stepped‐impedance‐stub loaded interdigital capacitor resonator for design of a dual‐band band‐pass filter with a large bandwidth ratio. The presented resonator has strong and weak couplings in the upper passbands (UPs) and lower passbands (LPs), respectively, so as to form a large upper/lower bandwidth ratio. Adopting a dual‐branch phase‐matched feedline structure can meet the external quality factors required for the UP/LP. Therefore, these two passbands, defined by their respective center frequencies and bandwidths, can be manipulated independently. A four‐pole dual‐band example filter with a lower bandwidth of 20 MHz at 1576 MHz and an upper bandwidth of 200 MHz at 2450 MHz is successfully designed on an YBCO/MgO superconducting wafer. The filter exhibits excellent frequency responses. The upper/LPs show insertion losses below 0.07/0.22 dB and return losses above 15.3/15.3 dB. The stopband rejection is better than 57 dB until the first spurious passband up to 6150 MHz (3.9fL).  相似文献   

11.
    
This article presents realization of low loss, wide stop‐band suspended substrate stripline (SSS) wideband pass filters using interdigital and stepped‐impedance resonators. SSSs have been characterized using the finite‐difference method (FDM). The experimental results of the fabricated filters are compared with the theoretical results. © 2005 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2006.  相似文献   

12.
    
A novel technique is presented to design highly compact microstrip ultra‐wideband (UWB) bandpass filters that exhibit high selectivity quasi‐elliptical response. The design is based on transversal signal‐interaction concepts that enable the inclusion of single or dual notch‐bands within the filter's passband to eliminate interference from other services that coexist within the UWB spectrum. The filter configuration comprises of two transmission paths which include folded T‐shaped stepped impedance resonators (SIRs) that are capacitively coupled with the input/output lines to enable signal transmission. It is shown that by combining the filters of different passband centre frequencies an UWB filter can be realised with either a single‐ or dual‐notch function. The theoretical performance of the filter is corroborated via measurements to confirm that the proposed filter exhibits UWB passband of 123% for a 3 dB fractional bandwidth, a flat group‐delay with maximum variation of less than 0.3 ns, passband insertion loss less than 0.94 dB, high selectivity, a sharp rejection notch‐band with attenuation of ?23 dB, and a good overall out‐of‐band performance. Furthermore, the filter occupies a significantly small area of 94 mm2 compared with its classical counterparts. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:549–559, 2014.  相似文献   

13.
    
A modified design approach for compact ultra‐wideband microstrip filters with cascaded/folded stepped‐impedance resonators is described. The key feature of the proposed method is to facilitate stronger coupling between stepped‐impedance resonators and, at the same time, eliminate the requirement of extremely small gaps in coupled‐line sections, as found in traditional designs. Simulations and measurements demonstrate that the filters designed with this technique exhibit good reflection, insertion‐loss, and group‐delay performance within the 3.1–10.6 GHz band. © 2009 Wiley Periodicals, Inc. Int J RF and Microwave CAE 2010.  相似文献   

14.
    
A novel compact balun‐diplexer applying new interdigital line resonators (ILRs) is presented in this article. It is found that the proposed ILR can not only reduce circuit size and but also realize high common mode rejection in differential mode operation frequency. By properly converting the symmetric four‐port balanced bandpass filter (BPF) to a three‐port device, a balun BPF with high selectivity and compact size are accomplished using ILRs. Then, the balun‐diplexer can be realized by combining two well‐designed balun filters with two 50 Ω transmission lines. The demonstrated balun‐diplexer with operation at 1.8 and 2.45 GHz have been designed, fabricated, and measured. Excellent performances have been observed. Specifically, 0.4 dB in‐band amplitude error, 1.8 in‐band phase error, more than 50 dB selectivity and 45 dB isolation are obtained. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:485–489, 2015.  相似文献   

15.
    
New multi‐standard wide band filters with compact sizes are designed for wireless communication devices. The proposed structures realize dual‐wideband and quad‐wideband characteristics by using a new skew‐symmetrical coupled pair of asymmetric stepped impedance resonators, combined with other structures. The first and second dual‐wideband filters realize fractional bandwidths (FBW) of 43.2%/31.9% at the central frequencies (CF) of 1.875/1.63 GHz, and second bandwidths of 580 MHz/1.75 GHz at CF of 5.52/4.46 GHz, respectively. The proposed quad‐band filter realizes its first/second/third/fourth pass bands at CF 2.13/5.25/7.685/9.31 GHz with FBW of 46.0%/11.4%/4.6% and 5.4%, respectively. The wide pass bands are attributed to the mutual coupling of the modified ASIR resonators and their bandwidths are controllable by tuning relative parameters while the wide stop band performance is optimized by the novel interdigital cross coupled line structure and parallel uncoupled microstrip line structure. Moreover, the quad band is generated by introducing the novel defected rectangle structure. These multi‐standard filters are simulated, fabricated and measured, and measured results agree well with both simulated results and theory predictions. The good in‐band and out‐of‐band performances, the miniaturized sizes and simple structures of the proposed filters make them very promising for applications in future multi‐standard wireless communication.  相似文献   

16.
    
A novel multistubs loaded resonator (MSLR) is proposed in this article, which is constructed by several open‐ and short‐circuited stubs. The analysis shows that it is characterized by four resonant modes. Then, the MSLR is applied in the design of a compact ultra‐wideband (UWB) bandpass filter. The measured results show that its 3dB bandwidth can cover [3.0, 11.5] GHz, that is, 3 dB fractional bandwidth is 117%, and the return loss within the passband is greater than 15 dB. Especially, the roll‐off rate is higher than 33 dB/GHz and more than 40 dB harmonic suppression can be achieved up to 17 GHz. In order to suppress the interference of some undesired narrowband signal such as wireless local‐area network (WLAN) radio signal, a notched band is created for the UWB bandpass filter, which is realized by forming one stepped slot on each of the feedlines, respectively. The measured results show that a notched band with 2.01% fractional bandwidth at the center frequency of 5.85 GHz can be achieved and its suppression is about ?19 dB.  相似文献   

17.
    
This study aimed to design and fabricate a lowpass‐bandpass (LP‐BP) diplexer with high isolation for telecommunication applications including wireless communications. The results revealed that the ?3 dB cutoff frequency of the lowpass filter (LPF) was equal to 0.82 GHz. The advantages of the LPF section include a very high suppression factor (SF) parameter (about 4.4), very sharp roll‐off‐rate (ROF or ζ) parameter (687), and a very high figure of merit (FOM) (about 233491). The bandpass filter (BPF) section was designed applying dual‐mode resonators with triband. The central frequencies of these tribands were equal to 2.38, 3.93, and 5.65 GHz. In the following, an SMV‐1247‐079LF SMD varactor diode is used to adjust the proposed LPF. The tuning range for the proposed LPF is 0.3‐0.72 GHz. In the proposed diplexer, the isolation between the output ports was higher than 45 dB. The results of measurements were in good agreement with those of the simulation.  相似文献   

18.
    
In this article, a new class of dual‐/tri‐band and ultra‐wideband (UWB) bandpass filters (BPFs) using novel multi‐mode resonators are proposed. The classical even‐/odd‐mode method is applied to analyze the resonant characteristics of the proposed resonators, which exhibit controllable resonant modes with different dimension parameters under the same configuration. According to the analysis, three resonators with quad‐/penta‐/sext‐mode resonant characteristics are obtained by choosing the specific dimension parameters. Then, the quad‐mode resonator is used to design a dual‐wideband BPF centred at 2.39/5.14 GHz with 3‐dB fractional bandwidths (FBWs) of 36.9%/18.9%, and the penta‐mode resonator is utilized to design an UWB BPF with 3‐dB FBW of 102.2%, whereas the sext‐mode resonator is applied to design a tri‐band BPF with centre frequencies of 2.09/3.52/5.46 GHz and 3‐dB FBWs of 11.3%/20%/12.1%. All these three filters are fabricated and measured, and the measured results are in good agreement with the simulated ones.  相似文献   

19.
    
A wideband diplexer is designed and developed in suspended substrate medium using wide‐bandpass filters of 10–14 GHz and 14–18 GHz. Tight coupling between resonators is achieved by etching the resonators on the top and bottom layers of the substrate. The diplexer is designed by combining these filters on a common transformer. Each filter is channelised to avoid waveguide modes. Suspended substrate striplines (SSSs) are characterized using the Finite‐Difference Method (FDM). The theoretical and measured results of the diplexer are presented. © 2006 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2006.  相似文献   

20.
    
A pair of dual mode independent controllable resonators used to realize dual band pass filter with good frequency selectivity and isolation is presented. The resonators are directly connected to input/output and are coupled through electric and magnetic coupling in two different paths. Magnetic coupling between the resonators is achieved using a common grounded via‐hole between the two set of quarter‐wavelength resonators. Electric coupling is achieved through open edge coupling of the resonators. Two independent resonators with Separate Electric and Magnetic Coupling (SEMC) paths produce an independently controllable dual band filter response and also additional transmission zeros (TZs) at the edges of the pass bands. The TZs are introduced to improve the selectivity of the filter. Filter exhibits desired pass band response at the Universal Mobile Telecommunications System (UMTS) band (1.95‐2.2 GHz) and Worldwide Interoperability for Microwave Access (WiMAX) band (3.4‐3.6 GHz). Proposed compact filter is implemented on RT/Duroid 5880 (εr = 2.2) substrate with thickness of 0.785 mm and surface area of 15 × 12 sq. mm.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号