Anil Kamma

Compact Bluetooth/UWB Dual-Band Planar Antenna With Quadruple Band-Notch Characteristics

A compact Bluetooth/Ultrawideband (UWB) dual- band planar antenna with quadruple band-notch characteristics is presented. The proposed structure consists of a UWB semi-elliptical planar monopole, attached to an approximate trapezoidal spiral for 2.45-GHz Bluetooth application. The proposed antenna utilizes rectangular resonant spiral structures for rejection of quadruple frequency bands, i.e., WiMAX (3.3-3.6 GHz), WLAN (5.15-5.35, 5.725-5.825 GHz), and ITU 8 GHz. These resonant spirals are capacitively coupled with the microstrip feedline. The band-notch characteristics are controlled by changing the effective length of the spirals along with coupling gaps between the feedline and the spirals. The proposed antenna also achieves sharp reduction in the gain and efficiency at all the notch frequencies. However , at the passbands, the gain and radiation efficiency are almost stable. A good agreement between the simulated and measured results shows that the proposed antenna with surface dimensions of 24 × 17 mm2 is suitable for Bluetooth/UWB dual-band applications.

Cross-Configured Directional UWB Antennas for Multidirectional Pattern Diversity Characteristics

A cross configuration of directional ultrawideband (UWB) antennas for multidirectional pattern diversity characteristics is presented. Initially, a printed UWB circular monopole having an asymmetric curve shaped CPW feed is designed as a base antenna for obtaining a directional radiation pattern, direction of which remains fairly same for the entire UWB. This base antenna is attached to similar antennas, in a four element cross-configuration to achieve multidirectional pattern diversity characteristics. The proposed structure provides high inter-element isolation of more than 20 dB, with an impedance bandwidth of 19.7 GHz, i.e., 1.3 GHz to 20 GHz. Transmission and diversity characteristics of the proposed antenna are analyzed. Good agreement between simulated and measured results indicates that the proposed antenna is suitable for UWB pattern diversity applications.

Reconfigurable dual-band notch UWB antenna

This paper presents a reconfigurable dual band-notched U-shape UWB (Ultra Wide Band) Microstrip line fed monopole antenna. Dual-Band notches are introduced by introducing `T shape resonator and etching dual reverse split ring slots (Complementary Split Ring Resonator (CSRR)). The proposed antenna revealed good UWB performance i.e. impedance bandwidth of 3.1 GHz-10.6 GHz with VSWR <; 2, accompanied by a adaptable dual band-rejection function (WLAN and WiMAX) in order to avoid interference caused from the IEEE 802.11a band and WiMAX band. The antenna is designed and simulated with FR4 (εr = 4.4) substrate having thickness of 1.59 mm with total size of 28×20 sq.mm.

MULTI-BAND NOTCH UWB BAND PASS FILTER WITH NOVEL CONTIGUOUS SPLIT RINGS EMBEDDED IN SYMMETRICALLY TAPERED ELLIPTIC RINGS

A compact multiple band-notch ultra-wide band (UWB) band-pass fllter (BPF) with surface area of 18£12mm 2 is introduced in this article. The proposed fllter is a combination of novel symmetrically tapered elliptic rings (STER) and contiguous split ring resonators (SRR), with stepped impedance resonator (SIR) structure to realize the multi-band notch UWB pass band characteristics. In the proposed structure, band-notches are generated for interfering microwave bands such as, WiMAX, WLAN and X-band applications. These notches are achieved by optimizing structural parameters of SRR sections. The proposed fllter is fabricated on RT/Duroid 5880 substrate with r = 2:2 and thickness of 0.787mm. The fabricated prototype is measured and a good agreement between simulated and measured results ensures suitability of the proposed fllter for UWB applications.

Compact printed monopole UWB antenna loaded with non — Concentric open — Ended rings for triple band — Notch characteristic

A compact, ultra-wideband monopole antenna with triple band-notch characteristic is presented. Proposed antenna consists of an elliptical radiator for achieving UWB bandwidth. For rejecting WiMAX (3.3-3.6 GHz) and WLAN (5.15-5.3 GHz, 5.7-5.825 GHz) bands, antenna is loaded with Non-concentric open ended rings. The effective lengths for these non-concentric rings are approximately half wavelength for the respective notch frequencies. Overall surface dimension of the fabricated antenna is 25×18 mm2. The proposed antenna is simulated, fabricated and tested experimentally for its performance. A good agreement between simulated and experimental results ensures the suitability of the proposed antenna for various UWB applications.

Dual-Band Filter for WiMAX and WLAN with Improved Upper Stop Band Performance

In this paper, a novel and compact dual-band fllter with enhanced upper stop characteristics has been presented. Dual band pass fllter characteristics are achieved by introducing transmission zero (TZ) in pass band of band pass fllter (BPF). The wide band pass fllter (BPF) is implemented by combining low pass fllter characteristics (i.e., stepped impedance resonator) and high pass fllter characteristics (i.e., short stubs). Closed rectangular ring resonator (CRRR) and open loop rectangular ring (OLRR) combination is used to produce two transmission zeros (TZs). One TZ is placed on the pass band of BPF such that resultant fllter characteristic consists of two pass band. However, the second TZ is placed at edge of the pass band in BPF to improve skirt selectivity. The two pass bands are designed to cover two popular wireless bands namely WiMAX (center frequency f1 (3.5GHz) and WLAN (center frequency f2 (5.7GHz)) bands, i.e., 3.35{3.65GHz and 5.5{5.85GHz respectively. Equi-ripple low pass stepped impedance resonator (SIR) fllter response is responsible for improved and spurious free upper stop band (> 20GHz, i.e., > 6f1) and also provides sharp skirt attenuation at upper stop band. The proposed fllter is implemented on an RT/Duroid 5880 (r = 2:2) substrate with thickness of 0.785mm and surface area of 19 £ 12sq ¢ mm. Good agreement between simulated and measured results ensures that the proposed fllter is a suitable candidate for modern dual band communications.

Printed band - notched u shaped ultra wide band antenna with modified split ring resonator

This paper presents a band-notched UWB (Ultra Wide Band) Microstrip fed monopole antenna. The band-notch of 5.1 - 5.8 GHz (VSWR >; 2) is easily achieved by inserting dual reverse split ring slots in the radiating monopole of the antenna. By properly adjusting the dimensions of the inserted slot, the proposed antenna revealed good UWB performance i.e. impedance bandwidth of 3 - 10 GHz with VSWR <; 2, accompanied by a band-rejection function (5.1 - 5.8 GHz) in order to avoid interference caused from the IEEE 802.11a band. Time domain response shows that the proposed structure exhibits a minimal and constant group delay (except for notch band) as needed for UWB application. The antenna is fabricated using FR4 (εr= 4.4) substrate having dielectric thickness of 1.59 mm with total size of 30×20mm.

Multiple band notch and Dual-Band filter using concentric and contiguous split ring resonators (CCSRR)

Abstract A novel, compact, multiple band notch filter and dual-band filters are presented. Contiguous and concentric split ring resonators (SRRs) and Ring resonator are used to achieve desired multiple narrow band notches. These band notches have been designed to avoid the undesired interference between co-existing wireless channels. The dual-band filter consists of a dual SRR having splits on the opposite sides with Inductive Short Stub Split Ring Resonator. Even- and odd-mode analyses have been performed to calculate the resonance frequencies. Three transmission zeros are achieved between the two passbands by both dominant electric or dominant magnetic coupling and also cancellation effect of electric and magnetic coupling. This results in high passband selectivity and improved band-to-band isolation. The proposed dual-band pass filter has the advantages of being compact with more degree of freedom to achieve desired passbands by controlling the electric and magnetic coupling independently. Proposed filter is implemented on RT/Duroid 5880 (εr = 2.2) substrate of thickness 0.785 mm and surface area of 0.27λg × 0.27λg. Insertion loss of the proposed filter at notch bands is high (>13 dB) and low (<0.8 dB) in pass band. Measured results correlate with the simulated results and thus ensure that the proposed filter is a suitable candidate to mitigate interference caused by the co-existing and emerging wireless technologies.

Multi Mode Resonators Based Triple Band Notch UWB Filter

A compact and highly selective triple band notch UWB (3.3 GHz -10.7 GHz) filter is presented. Low insertion loss UWB pass band characteristics is achieved by two coupled multi mode resonators (MMR₁ and MMR₂). Desired triple band notch characteristics and sharp UWB filter characteristics are achieved by introducing transmission zeroes (TZs). Three band notches are implemented to mitigate the potential interferer signals at 4.42 GHz (Radio altimeter ITU band), 5.54 GHz (WLAN) and 7.64 GHz (Satellite communications). Wide upper stop band is realized by incorporating a stepped impedance low pass filter structure. The filter is realized on a RT/Duroid 5880 substrate (<inline-formula> <tex-math notation=LaTeX>

A novel and compact dual band antenna using modified elliptical ring monopole

varepsilon _{mathrm {r}}=2.2