Pankaj Sarkar

A Compact UWB Bandpass Filter With Embedded SIR as Band Notch Structure

In this letter, an ultrawideband (UWB) bandpass filter with a band notch is proposed. The UWB BPF (3.1-10.6 GHz) is realized by cascading a distributed high-pass filter and an elliptic low-pass filter with an embedded stepped impedance resonator (SIR) to achieve a band notch characteristic. The notch band is obtained at 5.22 GHz. It is shown that the notch frequency can be tuned by changing the impedance ratio of the embedded SIR. A fabricated prototype of the proposed UWB bandpass filter is developed. The inband and out-of-band performance obtained by measurement, EM simulation, and that with an equivalent circuit model are in good agreement.

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.

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.

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.

Stepped Impedance Resonator Based U-Shaped Two-Element Monopole Microstrip Antenna Array

This paper presents stepped impedance resonator (SIR) based U-shaped two-element monopole microstrip antenna array. The stepped impedance resonator has been used to achieve a wideband response. The separation between the array elements has been optimized using fractal structures. Microstrip line feed has been used as the feeding network for the antenna array. The proposed design achieves the operating range of 800–1020 MHz (fractional bandwidth 24%) with a peak gain of 5.7 dBi at 1020 MHz. The antenna has been simulated using CST Microwave Studio (CST-MWS). The analytical characteristic of the proposed antenna agrees well with the simulated response.

A Compact Ku-Band Bandpass Filter with Wide Upper Stopband Using SIR

In this paper, a Ku-band bandpass filter with wide upper stopband characteristics is presented. The bandpass filter is implemented with a stub-loaded resonator (SLR). The resonator is designed to incorporate two resonating modes in the passband. Due to the presence of higher-order harmonics, the stopband is restricted to 25 GHz. To extend the stopband, the stepped-impedance stub (SIS) is connected at the input and output port. The proposed SIS stub has broad stopband characteristics, which extend the stopband up to 40.0 GHz. The proposed filter is analysed and simulated using a 3D EM solver. Simulated response agrees well with the analytical procedures.

A dual-band bandpass filter using integrated stepped impedance resonators

In this article, a compact dual-band bandpass filter (BPF) using integrated stepped impedance resonators (SIRs) is presented. The proposed filter topology consists of an outer open stub–loaded SIR to achieve lower passband of 2.45 GHz. The inner inter-coupled SIRs contribute to the 3.5 GHz band. The passband selectivity is achieved by introducing spur line in the input–output feed line sections that create a transmission zero at 2.2 GHz. A hook-shaped open stub is also added to bring about transmission zero at 4.55 GHz. The overall layout makes the filter compact with a size of 0.21 λg × 0.19 λg at 2.45 GHz. The insertion loss is within 1.75 dB for both the passbands. A prototype is developed with measured results in close agreement with the simulated results.

An ultra-wideband bandpass filter using multi stub resonator with notch band functionality

In this paper, a new method of forming an UWB BPF with notch band functionality has been presented. The design uses a multi stub loaded resonator on a Uniform Impedance Resonator (UIR) to form an Ultra Wideband (UWB) range and a rectangular spiral resonator to form a notch band at 5.55 GHz to avoid interference from existing narrow band radio signals. The passband insertion loss is within 0.5 dB. The filter exhibits a wide stop band till 15 GHz. Presence of a proper UWB range along with notch band and stop band characteristics are the ideal characteristics.