Showing papers on "Slot antenna published in 2007"
Book•
01 May 2007
TL;DR: In this article, Chen et al. present an approach for the design and evaluation of an Inverted-F Antenna with Coupled Floating Elements (INF) for low-bandwidth applications.
Abstract: Foreword. Acknowledgements. List of Contributors. 1 Introduction (Zhi Ning Chen). References. 2 Handset Antennas (Brian S. Collins). 2.1 Introduction. 2.2 Performance Requirements. 2.3 Electrically Small Antennas. 2.4 Classes of Handset Antennas. 2.5 The Quest for Efficiency and Extended Bandwidth. 2.5.1 Handset Geometries. 2.5.2 Antenna Position in the Handset. 2.5.3 The Effect of the User. 2.5.4 Antenna Volume. 2.5.5 Impedance Behavior of a Typical Antenna in the Low Band. 2.5.6 Fields and Currents on Handsets. 2.5.7 Managing the Length-Bandwidth Relationship. 2.5.8 The Effect on RF Efficiency of Other Components of the Handset. 2.5.9 Specific Absorption Rate. 2.5.10 Hearing Aid Compliance. 2.5.11 Economic Considerations. 2.6 Practical Design. 2.6.1 Simulations. 2.6.2 Materials and Construction. 2.6.3 Recycling. 2.6.4 Building the Prototype. 2.6.5 Measurement. 2.6.6 Design Optimization. 2.7 Starting Points for Design and Optimization. 2.7.1 External Antennas. 2.7.2 Balanced Antennas. 2.7.3 Antennas for Other Services. 2.7.4 Dual-Antenna Interference Cancellation. 2.7.5 Multiple Input, Multiple Output. 2.7.6 Antennas for Lower-Frequency Bands - TV and Radio Services. 2.8 The RF Performance of Typical Handsets. 2.9 Conclusion. References. 3 RFID Tag Antennas (Xianming Qing and Zhi Ning Chen). 3.1 Introduction. 3.2 RFID Fundamentals. 3.2.1 RFID System Configuration. 3.2.2 Classification of RFID Systems. 3.2.3 Principles of Operation. 3.2.4 Frequencies, Regulations and Standardization. 3.3 Design Considerations for RFID Tag Antennas. 3.3.1 Near-field RFID Tag Antennas. 3.3.2 Far-field RFID Tag Antennas. 3.4 Effect of Environment on RFID Tag Antennas. 3.4.1 Near-field Tags. 3.4.2 Far-field Tags. 3.4.3 Case Study. 3.5 Summary. References. 4 Laptop Antenna Design and Evaluation (Duixian Liu and Brian Gaucher). 4.1 Introduction. 4.2 Laptop-Related Antenna Issues. 4.2.1 Typical Laptop Display Construction. 4.2.2 Possible Antennas for Laptop Applications. 4.2.3 Mechanical and Industrial Design Restrictions. 4.2.4 LCD Surface Treatment in Simulations. 4.2.5 Antenna Orientation in Display. 4.2.6 The Difference between Laptop and Cellphone Antennas. 4.2.7 Antenna Location Evaluations. 4.3 Antenna Design Methodology. 4.3.1 Modeling. 4.3.2 Cut-and-Try. 4.3.3 Measurements. 4.4 PC Card Antenna Performance and Evaluation. 4.5 Link Budget Model. 4.6 An INF Antenna Implementation. 4.7 Integrated and PC Card Solutions Comparison. 4.8 Dualband Examples. 4.8.1 An Inverted-F Antenna with Coupled Elements. 4.8.2 A Dualband PCB Antenna with Coupled Floating Elements. 4.8.3 A Loop Related Dualband Antenna. 4.9 Remarks on WLAN Antenna Design and Evaluations. 4.10 Antennas for Wireless Wide Area Network Applications. 4.10.1 INF Antenna Height Effects on Bandwidth. 4.10.2 A WWAN Dualband Example. 4.11 Ultra-Wide Band Antennas. 4.11.1 Description of the UWB Antenna. 4.11.2 UWB Antenna Measurement Results. References. 5 Antenna Issues in Microwave Thermal Therapies (Koichi Ito and Kazuyuki Saito). 5.1 Microwave Thermal Therapies. 5.1.1 Introduction. 5.1.2 Classification by Therapeutic Temperature. 5.1.3 Heating Schemes. 5.2 Interstitial Microwave Hyperthermia. 5.2.1 Introduction and Requirements. 5.2.2 Coaxial-Slot Antenna. 5.2.3 Numerical Calculation. 5.2.4 Performance of the Coaxial-Slot Antenna. 5.2.5 Temperature Distributions Around the Antennas. 5.3 Clinical Trials. 5.3.1 Equipment. 5.3.2 Treatment by Use of a Single Antenna. 5.3.3 Treatment by Use of an Array Applicator. 5.3.4 Results of the Treatment. 5.4 Other Applications. 5.4.1 Treatment of Brain Tumors. 5.4.2 Intracavitary Microwave Hyperthermia for Bile Duct Carcinoma. 5.5 Summary. References. 6 Antennas for Wearable Devices (Akram Alomainy, Yang Hao and Frank Pasveer). 6.1 Introduction. 6.1.1 Wireless Body Area Networks. 6.1.2 Antenna Design Requirements for Wireless BAN/PAN. 6.2 Modelling and Characterization of Wearable Antennas. 6.2.1 Wearable Antennas for BANs/PANs. 6.2.2 UWB Wearable Antennas. 6.3 WBAN Radio Channel Characterization and Effect of Wearable Antennas. 6.3.1 Radio Propagation Measurement for WBANs. 6.3.2 Propagation Channel Characteristics. 6.4 Case Study: A Compact Wearable Antenna for Healthcare Sensors. 6.4.1 Application Requirements. 6.4.2 Theoretical Antenna Considerations. 6.4.3 Sensor Antenna Modelling and Characterization. 6.4.4 Propagation Channel Characterization. 6.5 Summary. References. 7 Antennas for UWB Applications (Zhi Ning Chen and Terence S.P. See). 7.1 UWB Wireless Systems. 7.2 Challenges in UWB Antenna Design. 7.3 State-of-the-Art Solutions. 7.3.1 Frequency-Independent Designs. 7.3.2 Planar Broadband Designs. 7.3.3 Crossed and Rolled Planar Broadband Designs. 7.3.4 Planar Printed PCB Designs. 7.3.5 Planar Antipodal Vivaldi Designs. 7.4 Case Study. 7.4.1 Small Printed Antenna with Reduced Ground-Plane Effect. 7.4.2 Wireless USB. 7.5 Summary. References. Index.
258 citations
TL;DR: In this article, a new internal multiband mobile phone antenna formed by two printed monopole slots of different lengths cut at the edge of the system ground plane of the mobile phone is presented.
Abstract: A new internal multiband mobile phone antenna formed by two printed monopole slots of different lengths cut at the edge of the system ground plane of the mobile phone is presented. The antenna can generate two wide bands centered at about 900 and 2100 MHz to cover the GSM850/GSM900/DCS/PCS/UMTS bands and the 2.4-GHz WLAN band. Further, the antenna has a simple planar structure and occupies a small area of only. It is also promising to bend the antenna into an L shape to reduce its volume occupied inside the mobile phone. Good radiation characteristics are obtained over the two wide operating bands.
227 citations
TL;DR: In this article, the authors demonstrate that the horizontal multiple slot configuration provides enhanced optical confinement in low index slot regions compared to a horizontal single slot structure with the same total SiO2 layer thickness.
Abstract: We experimentally demonstrate the optical transmission at 1550 nm of the fundamental slot modes (quasi-TM modes) in horizontal single and multiple slot waveguides and ring resonators consisting of deposited amorphous silicon and silicon dioxide. We demonstrate that the horizontal multiple slot configuration provides enhanced optical confinement in low index slot regions compared to a horizontal single slot structure with the same total SiO2 layer thickness by comparing their thermo-optic coefficients for the horizontal slot ring resonators. We show in these early structures that horizontal slot waveguides have low propagation loss of 6~7 dB/cm. The waveguide loss is mainly due to a-Si material absorption. The addition of a-Si/SiO2 interfaces does not introduce significant scattering loss in a horizontal multiple slot waveguide compared to a horizontal single slot waveguide.
216 citations
TL;DR: In this article, the design of passive and semi-passive transponder antennas for radio frequency identification applications involving the human body as the object to be tagged or bio-monitored is addressed.
Abstract: This paper addresses the design of passive and semi- passive transponder antennas for radio frequency identification applications involving the human body as the object to be tagged or bio-monitored. A planar tag antenna geometry, that is based on a suspended patch fed via a nested slot and is able to host sensors and electronics, is here introduced. Guidelines for conjugate impedance matching are given for different kinds of microchip transmitters, within power limitations as well as space constraints. Finally, the antenna matching performance is experimentally evaluated utilizing a body-tissue phantom.
215 citations
198 citations
TL;DR: In this article, the authors studied electrically small resonant antennas composed of split ring resonators (SRR) and monopoles, which have the same ring radius, but slightly different geometry.
Abstract: We studied electrically small resonant antennas composed of split ring resonators (SRR) and monopoles The antennas considered have the same ring radius, but slightly different geometry The resonance frequency depends on the geometry of the SRRs Two SRR antennas are designed The first one, which operates at 362 GHz, is demonstrated theoretically and experimentally The size of this antenna is 0095λ0×0100λ0 and is low profile at the other dimension The gain and directivity of the antenna was 238 and 546, respectively The corresponding efficiency was 436% The estimated radiation Q (rad Q=2303) was much larger than the minimum radiation Q (min Q=178) The second one is a rather small SRR antenna in which the capacitance between the rings is increased The size is reduced to 0074λ0×0079λ0 This structure is called serrated SRR (SSRR) Both antennas have similar far-field patterns but the efficiency of the SSRR antenna is less
188 citations
TL;DR: In this paper, a U-slot microstrip antenna with an E shaped stacked patch is presented, which achieves an impedance bandwidth of 59.7% and a voltage distribution of electric current distributions on the patch and the radiation patterns.
Abstract: A new design of a U-slot microstrip antenna with an E shaped stacked patch is presented that achieves an impedance bandwidth of 59.7%. Parameters such as substrate thickness, slot length, width are investigated and design results from parametric simulations are presented. The electric current distributions on the patch and the radiation patterns are also demonstrated in this paper.
182 citations
TL;DR: In this article, the authors present a method to calculate the notch frequency of printed monopole or dipole type UWB antennas, which is validated by comparing theoretical and experimental results for 19 different slot width, slot length and dielectric constant combinations.
Abstract: To prevent interference between ultrawideband (UWB) systems and existing wireless systems, creating notches in the UWB radiated field spectrum has been proposed. This filtering effect can be achieved by integrating a slot resonator to a UWB antenna. However, in printed monopole or dipole type UWB antennas, the notch frequency of the embedded slot depends on substrate and slot parameters. In this paper, we present a method to calculate, very accurately and efficiently, the notch frequency of such antennas. This method is validated by comparing theoretical and experimental results for 19 different slot width, slot length and dielectric constant combinations. The average difference is about 2%. We also assess the filtering action of slots from two aspects: the mismatch loss at the input and the radiation level in the far field. The sensitivity of the notch frequency to antenna parameters is also investigated.
151 citations
TL;DR: In this paper, the performance of wearable textile antennas is affected on the antenna bending, and the authors focus on the resonance frequency fluctuation and input-match bandwidth variation due to antenna bending.
Abstract: How the performance of wearable textile antennas is affected on the antenna bending is described herein. The authors focus on the resonance frequency fluctuation and input-match bandwidth variation due to the antenna bending. The results are given for three different antennas, namely, a conventional patch, EBG, and dual-band U-slot antennas
148 citations
Patent•
12 Jan 2007
TL;DR: In this article, an antenna assembly consisting of an antenna portion (20) and an electrooptic waveguide portion (30) is provided, where the antenna portion comprises at least one tapered slot antenna (24, 26).
Abstract: In accordance with one embodiment of the present invention, an antenna assembly (10) comprising an antenna portion (20) and an electrooptic waveguide portion (30) is provided. The antenna portion (20) comprises at least one tapered slot antenna (24, 26). The waveguide portion comprises at least one electrooptic waveguide (32). The electrooptic waveguide comprises a waveguide core (35) extending substantially parallel to a slotline (22) of the tapered slot antenna in an active region (15) of the antenna assembly. The electrooptic waveguide at least partially comprises a velocity matching electrooptic polymer (38) in the active region of the antenna assembly. The velocity ve of a millimeter or sub-millimeter wave signal traveling along the tapered slot antenna
the active region is at least partially a function of the dielectric constant of the velocity matching electrooptic polymer. In addition, the velocity v0 of an optical signal propagating along the waveguide in the active region is at least partially a function of the index of refraction of the velocity matching electrooptic polymer. Accordingly, the active region and the velocity matching electrooptic polymer can be configured such that v0 and v0 are substantially the same, or at least within a predetermined range of each other, in the active region. Additional embodiments are disclosed and claimed.
128 citations
TL;DR: In this article, an improved frequency notched ultrawideband (UWB) microstrip slot antenna with a square ring resonator embedded in the tuning stub is proposed, and the antenna is investigated numerically and experimentally for its impedance matching property and radiation performance in detail.
Abstract: An improved frequency notched ultrawideband (UWB) microstrip slot antenna with a square ring resonator embedded in the tuning stub is proposed. The antenna is investigated numerically and experimentally for its impedance matching property, frequency notched characteristic and radiation performance in detail. As will be reported, compared with conventional frequency notched slot antennas, after incorporating a square ring resonator with the slot antenna's tuning stub, high, sharp band-rejection characteristic of over 20 dB is achieved, which is improved significantly.
TL;DR: In this paper, a novel broadband design of a coplanar waveguide (CPW) fed T-shape slot antenna is proposed and experimentally studied, where the size of the proposed antenna is reduced by over 26% compared to the reported wide slot antenna.
Abstract: A novel broadband design of a coplanar waveguide (CPW) fed T-shape slot antenna is proposed and experimentally studied. The size of the proposed antenna is reduced by over 26% compared to the reported wide slot antenna. The obtained results show that the impedance bandwidth, determined by 10-dB return loss, of the proposed slot antenna can be as large as 5690 MHz or about 121% centered at about 4.695 GHz. The design considerations for achieving broadband operation of the proposed slot antenna are described, and experimental results are presented.
TL;DR: In this paper, a DGS slot with an interdigital shape was introduced, where the resonant frequency of the slot can be easily controlled by changing the length of the metal fingers without changing the area taken by the structure.
Abstract: This letter introduces a DGS slot with an interdigital shape. The resonant frequency of the slot can be easily controlled by changing the length of the metal fingers, without changing the area taken by the structure. Using this slot, two quasi-elliptic low-pass filters were designed, fabricated and tested. The filters have a cut-off frequency of about 3 GHz.
TL;DR: In this paper, a new design of a circularly polarised square slot antenna loaded with a cross patch is presented, where the cross patch inclined diagonally with respect to the square slot is placed at the center of the square-slot.
Abstract: A new design of a circularly polarised square slot antenna loaded with a cross patch is presented A cross patch inclined diagonally with respect to the square slot is placed at the centre of the square slot By choosing proper dimensions of the cross patch, two orthogonal resonant modes with a 90deg phase difference for circular polarisation can be excited and feed the square slot antenna using a 50 Omega CPW with a protruded signal strip 10 dB return loss bandwidth of 846 MHz (396%) and 3 dB axial ratio bandwidth of 240 MHz (124%) for the proposed antenna are achieved Gain variation within the CP bandwidth is observed to be less than 1 dB
TL;DR: In this paper, a compact printed ultra-wideband slot antenna with superior multiple band-notched characteristics is presented, and multiple split ring resonators are printed inside the inner patch to achieve multiple notch frequency bands.
Abstract: A compact printed ultra-wideband slot antenna with superior multiple band-notched characteristics is presented. The size of the UWB slot antenna is minimized, and multiple split ring resonators are printed inside the inner patch to achieve multiple notch frequency bands. As a practical example, a UWB antenna (working from 2.4 to 10.1 GHz) etched with two sets of split ring resonators are fabricated and its VSWR and radiation patterns are measured. The measured results agree well with the simulation, and the two notch frequency bands are centered at 3.65 and 5.75 GHz. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 3056–3060, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22892
TL;DR: In this paper, a genetic algorithm (GA) is applied to the design of planar monopole antennas, which exhibit both ultrawideband (UWB) operation and a narrow-band frequency notch.
Abstract: Genetic algorithm (GA) optimization is applied to the design of planar monopole antennas, which exhibit both ultrawideband (UWB) operation and a narrow-band frequency notch. Such an antenna is useful in applications involving wideband communications where it is desired to mitigate interference with other radio systems colocated with the operating band. It is demonstrated in this paper that traditional band-notched planar monopole antennas exhibit asymmetry in radiation patterns within the notch band such that the attenuation provided by the antenna varies as a function of azimuth angle, which lowers the effective bandwidth of the notch. A GA optimizer, which uses of a weighted sum cost function related to impedance matching and radiation patterns at frequencies within both the wide operating band and narrow notch band, is used to improve the performance of the band-notch planar monopole antenna. A two-dimensional (2-D) matrix chromosome is used in the GA to represent a wide-range on planar element shapes. It is shown that the GA generates antenna designs that exhibit equal wideband performance as traditional band-notched designs, but have improved azimuth plane radiation pattern symmetry, which widens the effective notch bandwidth. The GA-generated antenna design is measured and compared with simulation
Patent•
08 Mar 2007
TL;DR: In this paper, a lifetime detection device with a wave guide filter for blocking the microwave power of normal oscillation and making the microwaving power of abnormal oscillation pass through is provided.
Abstract: PROBLEM TO BE SOLVED: To provide a lifetime detection device of a magnetron capable of detecting a lifetime of the magnetron at a life-ending time as early as possible. SOLUTION: A lifetime detection device 21 having a wave guide filter for blocking the microwave power of normal oscillation and making the microwave power of abnormal oscillation pass through is provided, and fitted at a wave guide system circuit 18 of microwave power. When the magnetron 17 outputs microwave power generated by the abnormal oscillation, the microwave power of the abnormal oscillation is transmitted from a slot antenna of the wave guide system circuit 18 to the wave guide filter. From the action of an alarm corresponding to the microwave power of a coaxial wire terminal 16 appearing by the reception of the lifetime detection device 21, the life-ending time of the magnetron 17 is notified. COPYRIGHT: (C)2008,JPO&INPIT
TL;DR: In this paper, a dual-band coplanar waveguide (CPW)-fed monopole antenna with a cross slot is proposed, which is capable of generating two separate resonant modes with good impedance matching conditions.
Abstract: A novel dual-band design of a coplanar waveguide (CPW)-fed monopole antenna with a cross slot is proposed. The antenna, comprising a planar patch element embedded with a cross slot, is capable of generating two separate resonant modes with good impedance matching conditions. Prototypes of the proposed antenna have been constructed and experimentally studied. The measured results show both good agreement with the numerical prediction and good dual-band operation, with −10-dB impedance bandwidths of 13.7% and 28.3% at the resonant frequencies of 2.48 and 5.23 GHz, respectively, suitable for applications to the 2.4/5.2/5.8-GHz WLAN communication systems. Also, good monopole-like radiation patterns and antenna gains over the operating bands have been obtained. The design considerations for achieving dual-band operation of the proposed cross-slot antenna are discussed, and both theoretical and experimental results are presented.
TL;DR: In this article, the authors proposed a dual-frequency rectifying antenna (rectenna) operating at 2.45 and 5.8 GHz, which consists of two compact ring slot antennas, a hairpin lowpass filter and a rectifying circuit.
Abstract: This paper proposes a novel dual-frequency rectifying antenna operating at 2.45 and 5.8 GHz. The rectifying antenna consists of two compact ring slot antennas, a hairpin lowpass filter, and a rectifying circuit. The annual slot ring antenna uses a meander line structure to reduce its size to 52% of the regular ring slot antenna. The hairpin filter helps suppress the second order and the third order harmonics of both operation frequencies. The dual-frequency rectifying antenna (rectenna) achieves RF-to-dc conversion efficiencies of 65% and 46% at 2.45 and 5.8 GHz, respectively, while the power density is 10 mW/cm2. The rectenna is the smallest dual-frequency rectenna ever reported.
09 Jun 2007
TL;DR: In this article, a novel microstrip slot antenna for UWB (ultra wideband) antenna applications is proposed, which is filled by an H shape slot as a parasitic element.
Abstract: A novel microstrip slot antenna for UWB (ultra wideband) antenna applications is proposed. A square ring slot antenna is filled by an H shape slot as a parasitic element. This structure is fed by a single microstrip line with a fork like-tuning stub. Experiments are carried out to investigate its return loss, its radiation behavior, which exhibit good radiation pattern and impedance bandwidth over the entire band of frequency.
Patent•
13 Dec 2007TL;DR: In this article, a slot antenna resonating element is formed from an opening in the ground plane element of a handheld electronic device and a near-field-coupled antenna resonator is formed through electromagnetic near field coupling.
Abstract: A handheld electronic device is provided that contains wireless communications circuitry. The wireless communications circuitry may include antennas. An antenna in the handheld electronic device may have a ground plane element. A slot antenna resonating element may be formed from an opening in the ground plane element. A near-field-coupled antenna resonating element may be electromagnetically coupled to the slot antenna resonating element through electromagnetic near-field coupling. A transmission line may directly feed the slot antenna resonating element. The transmission line may indirectly feed the near-field-coupled antenna resonating element through the slot antenna resonating element. The slot antenna resonating element may have one or more associated resonant frequencies and the near-field-coupled antenna resonating element may have one or more associated resonant frequencies. The antenna may be configured to cover one or more distinct communications bands.
TL;DR: In this paper, a two-dimensional cylindrical Luneberg lens is introduced based on TE10 mode propagation between parallel plates, with special focus on ease of manufacturing, and the parallel plates are partially filled with low-cost polymer material (Rexolite epsivr = 2.54) to match Lunesberg's law.
Abstract: A new design of two-dimensional cylindrical Luneberg lens is introduced based on TE10 mode propagation between parallel plates, with special focus on ease of manufacturing. The parallel plates are partially filled with low cost polymer material (Rexolite epsivr = 2.54) to match Luneberg's law. A planar linear tapered slot antenna (LTSA) is inserted into the air region between the parallel plates at the edge of the Luneberg lens as a feed antenna, with fine positioning to the focal point of the Luneberg lens to optimize the antenna system performance. A combined ray-optics/diffraction method is used to obtain the radiation pattern of the system and results are compared with predictions of a time domain numerical solver. Measurements done on a 10-cm Luneberg lens designed for operation at 30 GHz agree very well with predictions. For this prototype, 3-dB E- and if-plane beamwidths of 6.6deg and 54deg respectively were obtained, and the sidelobe level in the E-plane was -17.7-dB. Although the parallel plate configuration should lead to a narrow band design due to the dispersion characteristics of the TE10 mode, the measurement results demonstrate broadband characteristics with radiation efficiencies varying between 43% and 72% over the tested frequency band of 26.5-37 GHz. The designed cylindrical Luneberg lens can be used to launch multiple beams by implementing an arc array of planar LTSA elements at the periphery of the lens, and can be easily extended to higher mm-wave frequencies.
01 Sep 2007
TL;DR: An experimental study concerning Ultra Wideband Microwave Radar for breast cancer detection is described and a successful detection of a target is accomplished by a visual inspection of a two-dimensional image of the scanned phantom.
Abstract: An experimental study concerning Ultra Wideband (UWB) Microwave Radar for breast cancer detection is described. A simple phantom, consisting of a cylindrical plastic container with a low dielectric constant material imitating fatty tissues and a high dielectric constant object emulating turnout, is scanned with a tapered slot antenna operating between 3.1 to 10.6 GHz. A successful detection of a target is accomplished by a visual inspection of a two-dimensional image of the scanned phantom.
TL;DR: In this article, the authors proposed a compact antenna with good impedance matching for ultrawide-band (UWB) impulse radio technology in the frequency band 3.1-10.6 GHz for commercial use.
Abstract: With the definition and acceptance of the ultrawide-band (UWB) impulse radio technology in the USA [1], there has been considerable research effort put into UWB radio technology worldwide. Recently, the Federal Communication Commission (FCC)’s allocation of the frequency band 3.1–10.6 GHz for commercial use has sparked attention on ultra-wideband (UWB) antenna technology in the industry and academia. Several antenna configurations have been studied for UWB applications [2–6]. It is of a particular interest to design a compact antenna with good impedance matching
TL;DR: In this article, a double-bent microstripline was proposed to feed the antenna at two different positions to achieve a circularly polarized annular-ring slot antenna, which achieved 10.5% axial-ratio bandwidth (ARBW) for the former and 10.0% for the latter.
Abstract: A novel design of a circularly polarized annular-ring slot antenna is discussed. The circular polarization is attained through a newly proposed double-bent microstripline that feeds the antenna at two different positions. Several structural parameters were experimentally studied with care to establish a design procedure, which was subsequently drawn into a design flow chart. Validation was carried out using the antennas designed at 3.5 and 1.59 GHz. The measured 3-dB axial-ratio bandwidth (ARBW) for the former is 10.5% and for the latter, 10.0%, which is larger than the 8.5% 3-dB ARBW required by an Inmarsat application.
TL;DR: In this article, the Koch iteration technique has been applied to obtain two fractal versions of a folded-slot antenna, the first iteration and the second iteration of a Koch folded slot antenna were designed, fabricated and characterized on a 30 mil thick RT/Duroid 6002 substrate.
Abstract: In this letter, the Koch iteration technique has been applied to obtain two fractal versions of a folded-slot antenna. A simple folded-slot antenna, first iteration and second iteration versions of a Koch folded-slot antenna were designed, fabricated and characterized on a 30 mil thick RT/Duroid 6002 substrate. The simple folded-slot antenna provides a return loss of 40 dB at the operating frequency of 10.45 GHz and the bandwidth for return loss greater than 10 dB is 1.211 GHz. The return loss of the first iteration of the Koch folded-slot antenna is 34 dB at 8.05 GHz and the bandwidth for 10 dB return loss is 0.4 GHz. The return loss of the second iteration of the Koch folded-slot antenna is 42 dB at 7.9 GHz and the bandwidth for 10 dB return loss is 0.34 GHz
TL;DR: In this article, an ultra wideband planar monopole antenna with a tunable band-notched response is proposed, which is realized by loading an embedded resonant slot with a varactor.
Abstract: An ultra-wideband (UWB) planar monopole antenna with a tunable band-notched response is proposed. Tuning of the rejected frequency is realised by loading an embedded resonant slot with a varactor. Simulations and measurements are presented for the proposed antenna, both in frequency and time domain.
TL;DR: In this paper, an annular-ring slot antenna that is suitable for the 2.4/5 GHz dual-band operations was miniaturized by embedding in the center patch of the antenna a pair of slots to excite three resonant modes.
Abstract: This letter aims at miniaturizing an annular-ring slot antenna that is suitable for the 2.4/5-GHz dual-band operations. The miniaturization purpose was achieved by embedding in the center patch of the antenna a pair of slots to excite three resonant modes. The resonant band of the first excited resonant mode was lowered from that of the unperturbed annular-ring slot antenna, whereas those of the second and third excited resonant modes were combined to form a wide upper operating band by appropriately adjusting the dimensions of the embedded slots. The proposed antenna proves to have very similar copolarization radiation patterns in its two operating bands and have enough antenna gains for practical applications.
Patent•
11 May 2007
TL;DR: In this article, an antenna component and antenna component with a dielectric substrate and a plurality of radiating antenna elements on the surface of the substrate is presented, where the lower edge of one of the antenna elements is galvanically coupled to the antenna feed conductor on a circuit board, and at another point to the ground plane.
Abstract: An antenna component (and antenna) with a dielectric substrate and a plurality of radiating antenna elements on the surface of the substrate. In one embodiment, the plurality comprises two (2) elements, each of them covering one of the opposite heads and part of the upper surface of the device. The upper surface between the elements comprises a slot. The lower edge of one of the antenna elements is galvanically coupled to the antenna feed conductor on a circuit board, and at another point to the ground plane, while the lower edge of the opposite antenna element, or the parasitic element, is galvanically coupled only to the ground plane. The parasitic element obtains its feed through the electromagnetic coupling over the slot, and both elements resonate at the operating frequency. Omni-directionality is also achieved. Losses associated with the substrate are low due to the simple field image in the substrate.