Band Notch Research Articles

Compact slot antenna with band-notch characterization for multifunctional communication systems

In this article, a compact design and construction of a wide slot antenna with band-notch characteristics of size 28 × 32 × 1.6 mm is proposed and developed for multifunctional communication systems. Detailed simulations and experimental investigations are performed to understand its behavior and to optimize for 2.4 GHz WLAN and ultrawideband operations. An FR4 substrate with a thickness of 1.6 mm and relative permittivity of 4.4 is used to design the antenna. The antenna has a modified rectangular stub with coplanar waveguide feed technique. The modified rectangular shaped stub excites similar shaped slot in the ground plane, which improves the impedance matching from 2.1 to 30 GHz for VSWR less than 2. In addition, notch band characteristics in the 5.1–5.9 GHz band are achieved by making a slot on the tuning stub. Numerical and experimental results are reported to access the performance of the antenna in terms of impedance matching and radiation characteristics. A good agreement is found between the simulation and experimental results. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:218–223, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27231

A novel compact UWB BPF with independently controllable double notched bands and super wide upper stopband

This paper presents a novel compact ultra-wideband bandpass filter without and with single or multiple notched bands with significant improvements in size reduction and upper stopband enhancement in comparison with its classical counterparts. A new multiple-mode resonator capable of producing multiple transmission zeros is exploited in the filter structure to produce notch bands and improve performance of the upper stopband. A parallel-coupled structure with tapped-line input/output is applied to significantly improve the selectivity and out-of-band rejection. The proposed filter achieves outstanding electrical performance, with wide passband from 2.93 to 10.64 GHz, two notched bands centered at 5.68 and 8 GHz with rejection level better than 40 dB, low insertion loss, high passband return loss, and wide stopband with suppression level better than −25 dB up to 30 GHz. These attractive features make the proposed filter a viable candidate for any number of broadband wireless communications and radar systems.

Directional UWB antenna with a parabolic ground structure and split ring resonator for a 5.8 GHz band notch

A simple and compact circular planar monopole ultra-wide band antenna with a 5.8 GHz band rejection and directional radiation pattern is proposed in this paper. The split ring resonator (SRR) technique has been utilized to produce band rejection at 5.8 GHz. Some results and analysis on several SRR placements are highlighted in this paper. The parabolic ground structure is used to produce a directional radiation pattern together with bandwidth enhancement. The proposed prototype antenna has acceptable performances in terms of gain, efficiency, and directional radiation pattern. Simulated and experimental results are discussed.

Controllable Band-Notched Slot Antenna for UWB Communication Systems

We propose a slot antenna consisting of a rectangular slot on the ground plane, fed by a microstrip line with a rectangular-ring-shaped tuning stub that can be deployed in ultra-wideband (UWB) communication systems to avoid interference with wireless local area network (WLAN) communication. Our antenna can achieve a single band-notched property from the 5 GHz frequency to the 6 GHz frequency owing to a controllable band notch that uses L- and J-shaped parasitic elements. The antenna characteristics can be modified to tune the band-notched property (4 GHz to 5 GHz or 6 GHz to 7 GHz) and the bandwidth of the band notch (1 GHz to 2 GHz). Furthermore, the shifted notch with enhanced width of the band notch from 1 GHz to 1.5 GHz is described in this paper. The UWB slot antenna and L- and J-shaped parasitic elements also provide the band-rejection function for reference in the WiMAX (3.5 GHz) and WLAN (5 GHz to 6 GHz) regions of the spectrum. Experiment results evidence the return loss performance, radiation patterns, and antenna gains at different operational frequencies.

A Band-Notched UWB Monopole Antenna With High Notch-Band-Edge Selectivity

In this paper, a novel band-notched ultrawideband (UWB) monopole antenna with high notch-band-edge selectivity is proposed and demonstrated. The proposed antenna consists of a radiation patch and an embedded second-order bandstop filter. Using the same substrate area as a fundamental UWB antenna, a bandstop filter composed of a nonuniform short-circuited stub and coupled open-/short-circuited stub resonators, is designed into the fundamental antenna. A detail design procedure for the proposed antenna with a second-order maximally flat bandstop filter at 5.5 GHz is presented. As compared to the fundamental antenna, the proposed UWB antenna provides good notch-band suppression from 5.15 to 5.95 GHz, in which the normalized total radiated powers in the notch band are lower than -12 dB. Also, the proposed structure provides high band-edge selectivity and flat return loss in the notch band. The measured results, including the return loss and total radiated power, agree with the designed ones.

Compact UWB Bandpass Filter With Dual Notch Bands Using Open Circuited Stubs

In this letter, an ultra-wideband (UWB) bandpasss filter with multiple notch bands is presented. The UWB bandpass characteristic is achieved using a modified distributed highpass filter (HPF) and suppressing higher order harmonics of the HPF by realizing defected stepped impedance resonator. The dual band notches at 5.75 and 8.05 GHz are obtained by embedding two open stubs on the main microstrip line. The in band and out of band performance obtained from fullwave electromagnetic simulation, equivalent circuit model and measurement are in good agreement.

A novel elliptic microstrip FED antenna with double band notched characteristic for UWB application

AbstractA compact ultrawideband microstrip‐fed monopole antenna with two band notch property is presented.The antenna consists of a truncated elliptic patch with half wave arc slot and two parasitic bent elements in both side of the radiating patch. It is designed with half elliptic ground plane in the back of the radiating patch. The antenna provides an enhanced impedance matching characteristic over the desired frequency band, with variable dimensions which are used to generate the frequency band stop performance in wireless local area network and the worldwide interoperability for microwave access frequency bands. The antenna is designed and measured successfully. The measured results show that this antenna operates over the frequency band between 2.2 and 11.5 GHz for S11 < 10 dB, while showing the band rejection performances in the frequencies band of 3.2–3.8 GHz and 5.2–5.8 GHz. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2659–2662, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27130

Band-reject ultra-wideband monopole antenna using patch loading

Proposed is a new simple technique for achieving band rejection characteristics in ultra-wideband monopole antennas. Two band notches were added to an existing UWB antenna by gluing a padding patch printed on a small single-layer piece of commercial substrate. The design of the new proposed structure has a controllable rejection in the 5 GHz WLAN and 8 GHz ITU frequencies while maintaining a wideband performance from 2.9 GHz to more than 12 GHz based on VSWR≤2. A good agreement between measurement and simulation was achieved. Measurements confirm that the technique introduces negligible antenna radiation pattern distortion except at the notched frequencies.

Design and Optimization of Integrated Bluetooth and UWB Antenna With Dual Band-Notched Functions

A compact microstrip-fed printed planar integrated Bluetooth and ultra wideband (UWB) monopole antenna with dual band-notched characteristics in the 3.5 GHz WiMAX and 5.2/5.8GHz WLAN band is presented. The proposed antenna design consists of the semicircular ring patch and partial ground plane. The extra band (2.33-2.5GHz)for Bluetooth is obtained by adding the T-shaped strip at the top of the patch. Additionally, two L-shaped arc slots in patch and two U-shaped circular slots in partial ground plane are etched to reject the WiMAX and WLAN bands. The numerical and experimental results show that the proposed antenna has an impedance bandwidth of VSWR ≤ 2 from 2.33 GHz to 2.5 GHz for Bluetooth band and 3.04 GHz to 10.8 GHz for UWB band except the notch band frequencies 3.34.1 GHz for WiMAX and 5 – 5.9 GHz for WLAN band.

Novel compact UWB antenna with reconfigurable dual‐band notches using pin diode switches actuated without λg/4 DC bias lines

AbstractThis article presents a simple and compact ultrawideband (UWB) microstrip antenna whose band limited notches can be dynamically reconfigured individually to circumvent the problem of interference encountered between UWB and WiMAX/WLAN systems. The coplanar waveguide‐fed antenna includes a defected ground structure (DGS) that generates the desired notch bands at the two aforementioned service bands. PIN diodes integrated within the DGS are used to electronically control the individual band limited notches without affecting each other's characteristics and the antenna's overall performance. The proposed technique offers the solution to the problem encountered in existing reconfigurable antennas which serve only one frequency band at a time. Furthermore, the proposed antenna use PIN diodes that do not need any dc bias line etched on the dielectric substrate, and thereby avoiding the problems associated with dc effects. Details of the antenna's design and simulation results are presented and validated with practical measurements. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2392–2397, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27066

Dual-band antenna with inserted edge resonators and U-slot DGS

A compact dual-band antenna for ultra-wideband (UWB) and Bluetooth applications with a notched band is presented. The proposed antenna consists of a beveled planar radiator with a pair of symmetrical edge resonators and a beveled ground, which exhibits a dual-band characteristic covering 2.4–2.48 GHz for Bluetooth and 3.1–10.6 GHz for UWB frequency bands. Then a U-slot defected ground structure (DGS) is involved to get a band notch characteristic to avoid the potential interference with existing WiMAX systems at 5.15–5.825 GHz. The antenna is simulated and measured, and the results show that the proposed antenna is a good candidate for both Bluetooth and UWB applications, which can suppress the potential interference with existing WiMAX systems.

Compact printed coplanar waveguide‐fed ultra‐wideband antenna with multiple notched bands

AbstractA compact multiband‐notched printed ultra‐wideband (UWB) coplanar waveguide (CPW)‐fed slot antenna is presented. The band notched characteristic is achieved by creating quarter‐wavelength stubs in the ground plane. These stubs act as stop‐band filters along the feed line over certain narrow frequency bands. Addition of each stub to the antenna structure creates an extra independent notch band. Antenna with single, dual, triple, quadruple, and penta notch bands can be created by this technique. The notch bands can be chosen from practical frequency bands such as 3.5 GHz WiMAX, 5.2 and 5.8 GHz WLAN, 7.25–7.75 GHz for the downlink of X‐band satellite communication systems, and ITU at 8.2 GHz band all within the UWB range. Each of the notch bands can be tuned in frequency independently. The antenna has a small size (24 × 27 × 0.8 mm3), and almost stable omnidirectional radiation pattern. The prototype of the antenna is fabricated, and the measured results are in good agreement with the simulations. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2121–2126, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26998

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.

A CPW-Fed UWB Antenna with C-band/WLAN/X-band Notch Functions using Isosceles Triangular Resonator and Stepped Impedance Resonator

A CPW-fed circular wide slot UWB antenna with C-band, WLAN and X-band notch functions has been presented in this article. The two stop bands are obtained by etching an isosceles triangular resonator with an inner isosceles triangular stub in the circular radiation patch and a stepped impedance resonator with an inner stub in the CPW fed transmission line. The two notched bands can be tuned by changing the dimensions of isosceles triangular, stepped impedance resonator and the inner stubs to give tunable notched band functions. The proposed dual notched band UWB antenna has been designed in details and optimized by means of HFSS. The proposed antenna has a small size of 32x24x1.6mm3. The simulated and measured results show that the designed UWB antenna has an impedance bandwidth of 10.7GHz covering the frequency band from 2.8GHz to 13.5GHz for voltage standing-wave ratio (VSWR) less than 2, except the notch bands 4.0GHz-5.4GHz for C-band and WLAN, 8.2GHz-9.3GHz for X-band which are used in satellite and military communications. The article also refers some recent patents on UWB antenna design. Keywords: Notch band, isosceles triangular resonator, stepped impedance resonator, UWB antenna, ANTENNA STRUCTURE, Impedance bandwidth, designed antennas

Miniaturized coplanar waveguide-fed disk monopole antenna for ultra-wideband applications with improved wireless local area network band rejection

In this article, we first propose a miniaturized coplanar waveguide-fed disk monopole antenna with overall size of 14 mm × 22 mm. Measurement results show that the antenna has an ultrawide impedance bandwidth from 3 to 12 GHz and omnidirectional radiation pattern. Next, we introduce two U-shaped slots in the ground plane of the antenna to provide an improved band rejection in the wireless local area network frequency band. Experimental results indicate that the proposed band notch antenna has maximum voltage standing wave ratio (VSWR) of 25 in the desired rejection band. Measured gain for the proposed band notch antenna is around 0 dB and reduces to −15dB in the desired rejection band. Time domain performance of both the initial antenna and band notch antenna is also examined and the best detection template is presented. Computed total fidelity factors for both the initial and band notch antenna are greater than 0.9. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2013

Compact planar ultrawideband wide-slot antenna with an assembled band-notched structure

A simple and compact wide-slot antenna and its extended band-notched design are presented.The proposed antenna is etched on a piece of FR4 printed circuit board with an overall size of 30 × 28 × 0.8 mm3. It consists of a polygonal wide slot, a coplanar waveguide feeding line, and a circular metal ring. The antenna prototype achieves good impedance matching, a constant gain, and stable radiation patterns over an operating bandwidth of 3.1–10.6 GHz. Furthermore, after the addition of an assembled band-notch structure, which is formed by a pair of inverted L-shaped slits embedded in the ground plane and a T-shaped stub inside the metal ring, the proposed antenna exhibits band-notched characteristics and achieves a much sharper notch band at 5–6 GHz. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1654–1659, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26864

Ultra-Wideband Differential Bandpass Filter With Narrow Notched Band and Improved Common-Mode Suppression by DGS

A novel microstrip ultra-wideband (UWB) differential filter with narrow notched band based on the transversal signal- interference concept is presented. In order to enhance the interference immunity from undesired signals efficiently, the notched band is implemented by coupling with quarter wavelength shorted-line at input and output ports. By taking advantage of the bandgap characteristic of defected ground structure (DGS), a slot-line DGS is used for improving the common-mode rejection. In this work, at the center frequency of the notched band which is 2.45 GHz, about 7.3% bandwidth (2.35-2.53 GHz) is realized by full-wave simulator. Agreement between experiment and simulation is observed.

Asymmetric dual-line coupling strip for multiple notched bands: Theory and implementation

An asymmetric dual-line coupling strip (ADLCS) can provide main two paths for the signals, which make it possible to generate multiple transmission zeroes. The detailed analysis of the ADLCS is proposed in this paper. Based on the microwave network theory, the equivalent circuit of the ADLCS is also developed. Moreover, the structural parameters of ADLCS are studied by calculations and simulations. The center frequencies and bandwidths of the notch bands can be controlled by tuning the structural parameters. Obviously, The ADLCS can be used in the ultra-wideband (UWB) bandpass filter (BPF) to generate multiple notch bands within the passband. To demonstrate the performance of the ADLCS with UWB filter, the structure is applied to the input and output (I/O) of the single-stage UWB Y-shaped BPFs. The proposed UWB Y-shaped BPF has been designed, fabricated, and measured. The measured results agree with the predicted ones closely. The two notch bands of the fabricated UWB Y-shaped BPF centered at 4.5 and 8.1GHz have 10-dB rejection fractional bandwidths of about 5.6% and 5%, respectively.

Ultrawideband‐printed hexagonal monopole antennas with WLAN band rejection

AbstractIn this article, a printed regular hexagonal monopole antenna fed by a microstrip line has been presented for ultrawide bandwidth. The antenna is then modified to possess band rejection at the wireless local area network (WLAN) (5.15–5.88 GHz) by an inverted U‐shape slot within the radiating patch. The length and width of the U‐shape slot offer sufficient freedom for selecting and shifting the notched band. The impedance and radiation characteristics are presented and discussed in detail. From the results, it has been observed that the impedance BW, defined by VSWR ≤ 2, can reach a value of 10.04 GHz (3.11–13.15 GHz), while band stop function is in the frequency bands of 5.15–5.88 GHz. The proposed antenna peak gain varies 1.53–4.05 dB over the whole 2.74–11.05 GHz excluding in 4.95–5.92 GHz notch band. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1520–1525, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26831

Compact ultra‐wideband notch‐band bandpass filters using multiple slotline resonators

AbstractA novel extremely compact ultra‐wideband (UWB) bandpass filter (BPF) with a notch band is presented.The multiple slotline resonators have been applied to construct the UWB BPF and implement the notch band within the UWB passband. Based on the transmission‐line theory, the equivalent‐circuit model of the proposed UWB notch‐band BPF has been developed. The upper cut‐off frequency and passband bandwidth of the UWB BPF, as well as the center frequency of the notched band can be adjusted by tuning the structural parameters. The proposed compact UWB notch‐band BPF using multiple slotline resonators has been designed, simulated, and measured. The measured results agree with the simulated ones closely. The notched band centered at around 5.7 GHz has 10‐dB rejection fractional bandwidths of about 2%. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1132–1135, 2012