Manimala Pal

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.

AN ULTRA WIDEBAND MONOPOLE ANTENNA WITH MULTIPLE FRACTAL SLOTS WITH DUAL BAND REJECTION CHARACTERISTICS

A compact dual band notched Ultra-wideband (UWB) antenna with multiple Hilbert curve slots is proposed that exhibits an impedance bandwidth from 2.5GHz to 12GHz Hilbert curve slots result in band notch in the frequency range 5.15{5.85GHz assigned to IEEE 802.11a and HYPERLAN/2 as well as 7.9{8.4GHz band assigned to X-band uplink satellite communication systems. The antenna gain varies from 3dBi to 5dBi over the operating frequency. Stable radiation patterns throughout its operating frequency are obtained Over all antenna size is 25mm by 45.75mm including the ground plane. Simulation and measured result of the proposed antenna are in good agreement.

High-Selective Compact UWB Bandpass Filter With Dual Notch Bands

In this letter, a novel high selective UWB band pass filter (BPF) with dual notch bands is presented. UWB BPF is realized using open stub and short stub loaded resonator (SLR). The resonators are realized to incorporate four resonating modes in the UWB passband extending from 3.14 to 10.53 GHz. Two transmission zeroes at 3.01 and 10.68 GHz, near to the UWB passband, increases the selectivity of the filter. Half wavelength long spiral resonators as slots are implemented in ground plane to achieve notch band at 5.13 GHz and an inward folded resonator is placed near to the open SLR to achieve notch at 8.0 GHz. Measured passband insertion loss is within 1.5 dB. The prototype of the proposed UWB BPF is fabricated and measured. Simulated response of the designed BPF agrees well with the measured result.

Multiple fractal-shaped slots-based UWB antenna with triple-band notch functionality

A planar elliptical shape band-notched UWB antenna with multiple fractal-shaped slots and a Sierpinski fractal curve-shaped ring resonator at the back of the substrate is introduced in this paper. The proposed antenna exhibits a triple-band notch characteristic. Koch fractal slot etched from the radiator is responsible for creating notched band centred at 5.5 GHz for wireless local area network rejection. The Minkowski fractal slots in the ground planes create rejection characteristics at 8.1 GHz to avoid interference with X-band uplink satellite communication systems. The RFID rejection band centred at 6.8 GHz is achieved by using a Sierpinski fractal curve-shaped ring resonator at the back of the substrate. Sierpinski fractal slot of third iteration on the radiator contributes to an impedance bandwidth of 2.8–12 GHz with VSWR < 2 by improving matching at lower frequencies except at three notched bands. The antenna gain varies from 1.5 to 4 dBi over the band. Stable radiation patterns are obtained throughout its operating frequency. The antenna has a compact size of 41 mm × 45 mm.

A Distinctive Resonance: Multiband Bandpass Filter Design Techniques Using Multimode Resonators

It has been over a decade since stepped-impedance resonators (SIRs) first carved a niche in applications for multiband bandpass filter (BPF) design. This was the first class of resonator within the broad category of multimode resonator (MMR). Multiband filter design has seen subsequent development in other forms of MMRs, including stub-loaded resonators (SLRs), ring-loaded resonators, and the newly introduced fractal-shape resonators. In this article, we describe the different types of MMRs, along with their variations, that have led to emerging innovative design techniques for multiband BPFs.

A CPW - Fed Propeller Shaped Monopole Antenna with Super Wideband Characteristics

A super-wideband antenna based on a propeller shaped printed monopole with a CPW feed is presented in this paper. The enhanced bandwidth is obtained by modifying the disk of a conventional circular disk monopole to resemble a propeller. This design produces an extremely wide impedance bandwidth from 3 to 35GHz with an impedance bandwidth ratio of 11.6:1. The gain of the proposed antenna varies from 4dBi to 5.2dBi. The antenna has fairly stable radiation characteristics throughout its operating band. The developed prototype is fabricated and measured. Simulation and experimental results are in good agreement.

Realization of Miniaturized Quadrature Hybrid Coupler with Reduced Length Branch Arms Using Recursively Loaded Stubs

This paper presents a novel design of miniaturized microstrip quadrature coupler at 2.45GHz. The design topology is based on reduced transmission line branch arms using recursively loaded stubs that contribute to the compact size. The proposed coupler result in a size reduction of 70.4% when compared to a conventional branch line hybrid. The designed coupler provides, at the operating frequency, a 25dB isolation and exhibits equal power division at the output ports with quadrature phase difierence. A fabricated prototype is developed with simulation and measurement in close agreement.

MINIATURIZED UWB BANDPASS FILTER WITH DUAL NOTCH BANDS AND WIDE UPPER STOPBAND

In this paper, a miniature ultrawideband (UWB) bandpass fllter with dual notch bands and wide upper stopband is presented. The ultrawide passband characteristic is achieved using a microstrip to slot line transition, and a wide upper stop band is realized using an elliptical lowpass fllter. The dual band notches at 5.46GHz and 8.04GHz are obtained by incorporating defected microstrip structure in the input and output sections. A prototype of the proposed UWB bandpass fllter is fabricated and measured. The equivalent circuit of the proposed fllter is also presented. A good agreement between the measured, EM simulated and circuit simulated responses is obtained.

An UWB band pass filter with a notch band using stub loaded multi-mode resonator

In this paper a UWB band pass filter using multiple mode resonator (MMR) with a notch band is reported. The MMR is realized by loading an open stub at the center of a uniform impedance resonator. Two modes are located within UWB passband to achieve UWB band pass response. The resonator is coupled via input output feed line through interdigital coupled line with a high degree of coupling. In order to incorporate a notch band in UWB passband one arm of the interdigital coupled line is extended in outward direction. Out of phase cancellation model is implemented for notch band insertion at 6.8 GHz RFID frequency. The proposed UWB band pass filter is simulated and tuned to improve in band, out of band performance and also the notch characteristics.

Compact dual-band bandpass filter using asymmetric stepped impedance stub loaded multimode resonator

This paper presents, a dual-band bandpass filter using asymmetric stepped impedance stub loaded open loop resonator (OLR) for WLAN and WiMAX application. The outer OLR is realized to operate at lower passband of 2.45 GHz which is directly coupled to input and output ports whereas the asymmetric stepped impedance stub that loads the outer resonator contributes to 3.5 GHz passband. The introduction of asymmetric stepped impedance stub provides further control of improving the upper passband edge selectivity of second passband and in shifting the spurious modes away from second band thereby contributing to the wide upper stopband. The insertion loss is within 1.5 dB for each passband with 10 dB passband bandwidth of 250 MHz at both bands. A stopband up to 10 GHz is also obtained. A prototype is developed and the s-parameters obtained from electromagnetic simulation, equivalent transmission line model and measurement are in close agreement. The overall dimension of the filter is 25.45 × 15.89 mm 2 which renders it a compact size.