Design of compact stop-band extended microstrip low-pass filters by employing mutual-coupled square-shaped defected ground structures

A new technique to reduce the size, improve the rejection in the stop-band of a low-pass filter using modified defected ground structure (DGS) is proposed. An equivalent circuit model is used to study the DGS characteristics. The parameters are extracted by using a simple circuit analysis method. Several comparisons between the EM-simulations and the circuit simulations of the new structure are demonstrated to show the validity of the proposed equivalent circuit model. We demonstrated that the filter can provide a sharp transition domain and a wide rejection in stop-band. To further verify the new technique, a filter employing the new deformed DGS is fabricated and measured. The agreement between the simulation and the measured results confirms the effectiveness of the proposed concept. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1107–1111, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23273Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58033/1/23273_ftp.pd

Design and optimization of a new compact 2.4 GHz-bandpass filter using DGS technique and U-shaped resonators for WLAN applications

The objective of this work is the study, the design and the optimization of an innovative structure of a network of coupled copper metal lines deposited on the upper surface of a R04003 type substrate of height 0.813 with a ground deformed by slots (DGS). This structure is designed in an optimal configuration for use in the design of narrowband bandpass filter for wireless communication systems (WLAN), the aim of use the defected ground structure is to remove the unwanted harmonics in the rejection band, the simulation results obtained from this structure using CST software show a very high selectivity of the designed filter, a very low level of losses (less than-0.45 dB) with a size overall size of 43.5x34.3 mm

Design and Fabrication of Tri-Stopband Bandstop Filters Using Cascaded and Multi-Armed Methods

In this paper, we proposed a compact C-open-loop ring resonator and its equivalent circuit. The second cascaded BSF are designed using this simple C-ring resonator. The double ring BPF consists of two cascaded C-ring resonators, which are placed on the RO4003 substrate, while the other triple BSF structure consists of tree cascaded C-ring resonators, which are connected with input and output through microstrip feed lines. The both filters are simulated, optimized and partially realized using MWR simulator and Anritsu E5072A vector network analyzer VNA. In order to reduce the size and to improve the filter characteristics, novel compact filter topologies are designed basing on the previous structures. The proposed multi-band bandstop filters consist of several open-loop ring resonators placed vertically overlapping (coupled multi-armed ring resonator). Using this idea, the filter topologies with design flexibility, close size and excellent results are reached. The novel compact multi-band bandstop filters produce several stopband along a frequency range from DC to 9 GHz, in which each separate band exhibits an acceptable and useful bandwidth. Each stopband has regenerated two reflexion zeros, what leads to a good sharpness factors in the transition domains. Good agreement between the experimental results, full-wave simulation has been achieved. This new filter idea can be very attractive for the nowadays multilayer and compact radio frequency integrated circuit design

A Compact Wideband Monopole Antenna using Single Open Loop Resonator for Wireless Communication Applications

A novel single layer, microstrip line fed compact wideband monopole antenna using open loop resonator has been designed and analyzed. The proposed antenna occupies a compact size of only 30 36.5 1.6 mm3. A partial ground plane is employed to enhance the operating bandwidth and reflection coefficient of the proposed antenna. The variations in operating bandwidth of the proposed antenna can be easily controlled by properly adjusting the position of the gap in the open loop resonator.The antenna prototype is fabricated on FR4 substrate with a dielectric constant 4.2. In this design, the antenna exhibits 10dB wide impedance bandwidth of 61% from 2.0174 to 3.7903 GHz.The antenna can be easily fed using a 50 Ω microstrip feed line and it covers the bandwidth requirements of a number of modern wireless communication systems such as IEEE 502.11b WLAN band (2.4 2.5 GHz), extended UMTS (2.5 2.69 GHz), IMT (2.7 2.9 GHz), and IEEE 802.16 Wi MAX band (3.3 3.6 GHz) applications. The desired antenna is designed and simulated using Computer Simulation Technology (CST). An extensive analysis of the antenna parameters (reflection coefficient, radiation pattern, directivity, and VSWR) including surface current distributions is presented and discussed in this paper. Good agreement between simulated and measured result is obtained

Design and Fabrication of a Novel Quadruple-Band Monopole Antenna Using a U-DGS and Open-Loop-Ring Resonators

In this Article, a novel quadruple-band microstrip patch antenna is proposed for the systems operating at quad-band applications. The antenna structure is composed of modified rectangular patch antenna with a U-shaped defected ground structure (DGS) unit and two parasitic elements (open-loop-ring resonators) to serve as a coupling-bridge. The proposed antenna with a total size of 31×33 mm2 is fabricated and tested. The measured result indicates that the designed antenna has impedance bandwidths for 10 dB return loss reach about 180 MHz (4.4–4.58 GHz), 200 MHz (5.4–5.6 GHz), 1100 MHz (7.2–8.3 GHz), and 700 MHz (9.6–10.3 GHz), which meet the requirements of the wireless local area network (WLAN), worldwide interoperability for microwave access (WiMAX), C and X bands applications. Good agreement is obtained between measurement and simulation results