Ultra-wideband (UWB) microwave filters and design challenges are studied and, a microstrip UWBfilter prototype design is presented. The UWBbandpassfilter operating in the 3.6 GHz to 10.6 GHz frequency band is targeted to comply with the FCC spectral mask for UWB systems. The prototype filter is composed of quarter wavelength spaced shunt stub transmission lines. The circuit is first simulated and optimized by using ADS simulation software tool. The fabricated microstrip UWBbandpassfilter is then measured using a vector network analyzer and results are presented. The prototype built can be used in UWB communications or localization systems.
Abstract—A compact ultra-wideband (UWB) bandpassfilter (BPF) with improved harmonic suppression using a modified coupling structure is presented in this paper. The modified coupling structure is constructed by taper-connecting two folded open stubs to the traditional parallel-coupled lines, which shows an improved characteristic in harmonic suppression. By integrating the proposed coupling and the stepped-impedance stub loaded resonator (SISLR), a UWB BPF is finally built and tested. The simulated and measured results are in good agreement with each other, exhibiting good wideband filtering characteristic and improved out-of-band performance.
Abstract—A new microstrip ultra-wideband (UWB) bandpassfilter (BPF) with triple-notched bands is presented in this paper. The circuit topology and its corresponding electrical parameters of the initial microstrip UWB BPF are desired by a variation of genetic algorithm (VGA). Then, triple-notched bands inside the UWB passband are implemented by coupling a square ring short stub loaded resonator (SRSSLR) to the main transmission line of the initial microstrip UWB BPF. The triple-notched bands can be easily generated and set at any desired frequencies by varying the designed parameters of SRSSLR. For verification, a microstrip UWB BPF with triple-notched bands respectively centered at frequencies of 4.3 GHz, 5.8 GHz, and 8.1 GHz is designed and fabricated. Simulated and experimental results are in good agreement.
In this paper, a novel UWBbandpassfilter is proposed using a microstrip to slotline transition combined with an elliptical lowpass filter. The dual notches in UWB passband are implemented using two embedded open circuited stubs as defected microstrip structure. The proposed UWBfilter is realized using Taconic substrate of dielectric constant 2.2 and height 0.787 mm. Rest of the paper contains the filter design procedure in Section 2 followed by results and discussion in Section 3.
In this paper, a new compact UWBBandpassFilter-Crossover is proposed and implemented. The structure of the uniplanar device is composed of four UWB microstrip-to-CPS transitions and two section lines to create two diﬀerent UWB ﬁlters mounted on diﬀerent layers of the same substrate. To the best of our knowledge, no research works have been reported on designing of UWB ﬁlter based on both microstrip and CPS-MMR technologies. The proposed bandpassFilter-Crossover oﬀers a good performance in terms of compactness, bandwidth, isolation, insertion loss and wide out-of-band rejection.
The UWBbandpassfilter using hexagonal shaped MMR with 5 GHz notch band is presented in his paper to sup- press WLAN. The filter is implemented by integrating hexagonal MMR coupled with interdigital conductors of the filter. The developed BPF demonstrated with excel- lent ultra-wide passband from 2.2 GHz to 10.5 GHz with an insertion and return loss is about –2 dB and –36 dB respectively. Rejection performance for the filter is about –27 dB at the centre frequency of 5.4 GHz and the filter has good outband performance higher than the require- ment of FCC’s mask. The group delay obtained for bandpassfilter at the operating is about 0.2 ns and for notch filter it is below 0.1 ns. With the above structural features the overall dimensions of the filter are 38 mm (length) × 3.2 mm (breadth) × 1.6 (height) mm and the
this novel coupling structure, two modes are achieved by the strong coupling [11, 12] between the CPW and the microstrip line, whereas the other two modes are achieved by the tapered feed line. The sections from the short-ended microstrip line to tapered feed line are quarter-wavelength (at 6.85 GHz), and these two sections can modeled as a K-inverter. As a result, the network of the proposed structure can be described as Figure 3(b). Another four modes are achieved by two J -inverters and two K-inverters. The simulation of the proposed UWBbandpassfilter with tapered feed line is depicted in Figure 3(c).
A novel approach to design microstrip UWBbandpassfilter based on modified genetic algorithm is proposed in this paper. The modified genetic algorithm overcomes two possible drawbacks of conventional GA, i.e., slow rate of convergence and local-best solution. The algorithm is then applied to guide UWBbandpassfilter design. A new microstrip UWBbandpassfilter has been designed and measured to verify the proposed efficient design method. Results indicate that a class of filters can be designed using the proposed modified genetic algorithm. Due to its distinct properties of simple topology, compact size, and good performance, the designed filter has a great potential to be applied to modern UWB wireless communication systems.
Abstract—A novel ultra-wideband (UWB) bandpassfilter (BPF) with notched band based on microstrip/slotline ring resonators is presented in this paper. The UWB BPF is fabricated with two microstrip ring resonators on the top copper layer and a slotline ring resonator on the bottom ground layer. Thus, an ultra-wide passband can be achieved owing to the coupling effects and microstrip/slotline transitions of these three ring resonators. Then, a notched band which is created at 8.0 GHz for satellite communication system is designed based on loaded short-circuited stubs. Both the simulated and measured results show that this compact UWB BPF has good performances of wide passband and notched band.
Abstract—In this paper, a novel compact quintuple-mode UWBbandpassfilter (BPF) with sharp rejection skirt and wide upper- stopband performances is realized using stub-loaded multiple-mode resonator (MMR). The proposed resonator is formed by attaching two pairs of circular impedance-stepped open stubs in shunt and a pair of short-circuited stubs to high impedance microstrip line. By simply adjusting the radius of circular impedance-stepped open stubs and the lengths of short-circuited stubs, the first five resonant modes of the resonator can be roughly allocated within the 3.1–10.6 GHz UWB band meanwhile the high resonant modes in the upper-stopband can be suppressed. The short stubs in pairs can generate two transmission zeros near the lower and upper cut-off frequencies, leading to sharper rejection skirt outside the desired passband. Finally, a quintuple- mode UWB BPF is designed and fabricated, and the measured results demonstrate the feasibility of the design process.
Abstract—A new compact microstrip ultra-wideband (UWB) bandpass ﬁlter (BPF) with improved out-of-band rejection and good selectivity is proposed using a modiﬁed ring multiple-mode resonator (MMR). The initial UWBbandpass ﬁlter comprises interdigital coupled lines and a conventional ring MMR. Then, four high-low impedance resonant cells are periodically placed in the inner area of the conventional ring MMR, which have the properties of achieving harmonic suppression and size reduction. To validate the design theory, a new compact microstrip UWB BPF with improved out-of-band rejection is designed and fabricated. Both simulated and experimental results are provided with good agreement.
Abstract—A new compact ultra-wideband (UWB) bandpass ﬁlter (BPF) with triple sharply notched bands and good stopband performance has been studied and implemented using a triple-mode stepped impedance resonator (TMSIR). The proposed TMSIR is found to have the advantages of introducing triple-notched bands and providing a higher degree of freedom to adjust the resonant frequencies. To validate the design theory, a new microstrip UWB BPF with three notched bands respectively centered at 5.2 GHz, 6.8 GHz, and 9.2 GHz is designed and fabricated. The simulated and experimental results are provided with good agreement.
Twentieth century has seen remarkable developments in the field of telecommunications. Wireless communication is indeed a very promising area in the field of telecommunication that came into picture in the last century. Wireless replaces the wired communication, making the communication more easy and efficient. There is been many advancements in the field of wireless communication in the last two decades. One of the most important and promising advancements in the field of wireless communication is Ultra-Wide Band (UWB). Federal Communication Commission (FCC) authorized the unlicensed use of 7.5 GHz bandwidth of spectrum from 3.1 GHz to 10.6 GHz in the year 2002 for UWB communication. This led to opening of a new chapter in the wireless communication research. UWB communication has attracted the attention of many researchers worldwide since its inception. UWB is mainly used for indoor communication since it allows transmission of low power signals.
In February 2002, the Federal Communications Commission (FCC) declared the frequency band of 3.1 GHz to 10.6 GHz as unlicensed spectrum for ultra-wideband systems (UWB). This commission set up initial rules in commercial and industrial applications. In this report, bandwidth of 3.1 GHz to 10.6 GHz was considered as a UWB bandwidth [1–3]. However, unwanted radio signals of narrow band such as local area network (WLAN) and some satellite communication systems signals can interfere with UWB. Therefore, UWBbandpass ﬁlters with one or several notched bands are required to reject these interfering signals. Two important bands of unwanted signals are WLAN and satellite communication band which are in 5.8 GHz and 8 GHz [4–6].
Design of ultra wideband filters for using in wireless technology systems is mainly to transmit data over spectrum of frequency bands for short distance with very low power and high data rates As a key component of UWB communication system, the designed band pass filter should have low insertion loss over the operating band, good band rejection, which is important for many wireless applicatons.
To realize band-notched characteristics, we introduce an E-shaped resonator into the basic UWB BPF. It should be mentioned that the E-shaped resonator can be equivalent to two shunt-connected series resonance circuit when placed next to the microstrip line, i.e., it can result in dual band-notched performance. This structure is simple and flexible for blocking undesired narrow band radio signals that may appear in UWB band. The introduced E-shaped resonator is composed of a stepped impedance hairpin resonator with centrally loaded a short-ended stub. Figure 2 shows the layout of the E-shaped resonator coupled to the microstrip line and its corresponding equivalent circuit. Since the E-shaped structure is symmetrical to the A-A 0 plane, the resonance properties of E-shaped resonator can be
Finally,the designed UWB BPF is measured with an Agilent N5230A vector network analyzer. The comparison of the simulated and measured results is shown in Figure 7. It is found that the working frequency of the proposed UWB BPF is 3.1–10.6 GHz and notched band is 5.7–5.8 GHz. The insertion loss is less than 1.0 dB in pass- band. The measured rejection loss is more than − 30 dB at he midband
Abstract—A new approach to design a microstrip ultra-wideband (UWB) bandpass ﬁlter (BPF) with quad sharply notched bands and good selectivity is proposed using quad parallel defected microstrip structures (PDMSs). The initial UWB BPF comprises interdigital coupled lines and an E-shaped multiple-mode resonator (EMMR) to achieve two transmission zeros on both sides of the passband thus to improve skirt selectivity. Then, four PDMSs are introduced, which have the properties of achieving four band-notched characteristics and provide high degree of adjusting freedom. To validate the design theory, a new microstrip UWB BPF with four notched bands respectively centered at 5.3, 5.9, 6.4, and 7.4 GHz is designed and fabricated. Both simulated and experimental results are provided with good agreement. The designed methodology is very eﬃcient and useful for ﬁlter synthesis though the design principle is simple.
An arbitrary two-port microstrip circuit shown in Fig. 1(a) can be decomposed into basic circuit elements [17, 18] shown in Fig. 1(b). The circuit can be expressed as a data structure shown in Fig. 1(c). The data structure is composed of three parts. The ﬁrst part coded in integer represents the topology of basic element. The second part coded in integer represents the way of connection to the previous element. The third part coded in ﬂoating number represents the corresponding electrical parameters. In the GA, we deﬁne a basic circuit element as a gene and a set of basic circuit elements as a chromosome [19–21]. Therefore, an arbitrary two-port circuit can be represented by a chromosome. Table 1 is the details of the basic circuit elements. A special gene named Empty is introduced, which enables the representation scheme to be capable of describing a circuit with an arbitrary number of basic circuit elements and orders. In this work, we adopt a variation of GA technique to design a microstrip UWB BPF with improved design eﬃciency.
However, the existing wireless networks such as 4.5G satellite communication systems signals, 5.8 GHz WLAN signals, and some 8.0 GHz satellite communication systems signals can easily interfere with UWB users. Therefore, compact UWB BPF with multiple notched bands is emergently required to reject these interfering signals [9–15]. To achieve a notched band, one of two arms in the coupled-line sections is extended and folded in . On the other side, the coupling interdigital line is introduced to block undesired existing radio signals in . However, these two methods can only achieve one notched band. Thus, to introduce dual-notched bands, a coupled simpliﬁed composite right/left-handed resonator is introduced in , and two coupled stepped impedance resonators are employed in . However, the selectivity designed with these two methods need to be improved. By arranging two asymmetric meander open-loop resonators on middle layer and a C-shaped resonator on bottom layer  or embedding two open-circuit stubs into broadside-coupled stepped impedance resonators on middle layer , dual-notched bands can be introduced into an UWB BPF. Additionally, by integrating short- circuited stub resonators  or embedding a quarter-wavelength coplanar waveguide resonators and inserting a meander slot-line in the detached-mode resonator  can also realize dual-notched bands. However, these designs are based on multilayer technology which will increase the fabrication cost. A new method based on wave’s cancellation theory has been proposed to design an UWB BPF with dual- notched band in . However, the center frequencies and bandwidths of the notched bands cannot be