Showing papers presented at "International Workshop on Antenna Technology in 2009"
02 Mar 2009
TL;DR: In this paper, the authors present an LTE MIMO air interface solution for handsets using metamaterial designs, which offer small, low-cost, and low-profile antennas printed directly on PCB for easy integration and simple manufacturing.
Abstract: In the digital world, Moore's Law states the number of transistors on Integrated Circuits (ICs) has been doubling every two years since 1965. While these ICs occupy only 10% of the wireless communication device area, the remaining 90%, referred to as RF Front-End Model (FEM), consists of a collection of discrete passive and active components such as antennas, filters, diplexer, duplexers, couplers, power combiner/splitter, and power amplifiers. While these powerful ICs enable effective implementation of Multiple Input Multiple Output (MIMO) digital processing, the main issue of MIMO RF FEM implementation in small devices such as handsets still remains unsolved. Without such a full solution, network providers cannot deploy next generation wireless broadband networks, such as 3GPP Long Term Evolution (LTE) networks, that can sustain tens of Mbps throughput with mobility. This paper addresses this specific problem by presenting an LTE MIMO air interface solution for handsets using metamaterial designs, which offer small, low-cost, and low-profile antennas printed directly on PCB for easy integration and simple manufacturing - all critical factors for rapid deployment and commercial success. The proposed metamaterial MIMO array consists of dual resonance antennas occupying λ 0 /10 × λ 0 /41 × λ 0 /387 volume at center frequency 771MHz of the LTE band 746–796MHz. The performances of two antenna array configurations with spacing of λ 0 /13 and λ 0 /5 are studied while quantifying its near-filed and far-field channel correlation.
38 citations
02 Mar 2009
TL;DR: In this paper, a small size wideband microstrip patch antenna with slot in ground plane and stacked patch fed through microstrip line is presented, the antenna designed is based on Roger RT/duroid 5880 with dielectric constant 2.2.
Abstract: Small size wideband microstrip patch antenna with slot in ground plane and stacked patch fed through microstrip line is presented. By inserting slot on ground plane and stacked patch supported by wall, the bandwidth can improve up to 25% without significant change in the frequency. The bandwidth before adding the slot and the stacked patch was 3.72%, whereas after adding the slot and the stacked patch the bandwidth increased up to 25% ranging from 2.45 to 3.3 GHz. The radiation pattern has acceptable response at both E-plane and H-plane. The ground plane size is 30 mm by 90 mm, the antenna designed is based on Roger RT/duroid 5880 with dielectric constant 2.2.
32 citations
02 Mar 2009
TL;DR: Recent advances in biotelemetry, the challenges faced today, and opportunities for the future are described.
Abstract: Biomedical telemetry is used today to communication with cardiac devices, insulin pumps, and a few other implantable devices that are on the order of 1–2″ in diameter. Future systems promise advanced communication with cardiac, optical, neurological and auditory devices that are on the order of a centimeter in dimension. Miniaturized antennas and inductive coupling systems provide the radio interface between air and the implantable device. New materials and methods allow miniaturized communication systems to be seamlessly integrated within the medical device itself. This paper describes recent advances in biotelemetry, the challenges faced today, and opportunities for the future.
23 citations
02 Mar 2009
TL;DR: In this paper, a two-port vector network analyzer (VNA) is used to measure the UHF RFID tag antenna impedance using the measured S-parameters.
Abstract: A methodology to measure UHF RFID tag antenna impedance using network approach is presented. The balanced UHF RFID tag antenna is considered as a two-port network and the impedance of the antenna is characterized by network parameters. In the measurement, the balanced antenna is connected to the two ports of a two-port vector network analyzer (VNA) through a test fixture. The influence of the test fixture is de-embedded by using a portextension technique and then the antenna impedance is extracted directly from the measured S-parameters. The proposed method is validated by comparing the measured and the simulated impedance of an asymmetrical dipole antenna and a symmetrical meander line dipole antenna both for UHF RFID tags.
23 citations
02 Mar 2009
TL;DR: In this paper, the authors survey theoretical and experimental results on characterization of beam equivalent noise temperature and efficiency, impedance matching to minimize front end noise, and beamforming and calibration algorithms for phased array feeds.
Abstract: Instrumentation for radio astronomical observations is currently undergoing a transition from large reflectors with single-pixel feeds to multi-pixel phased arrays. Research efforts aimed at realizing the benefits of phased arrays for highly sensitive, calibrated astronomical measurements have opened up interesting challenges for antenna designers. This paper surveys recent theoretical and experimental results on characterization of beam equivalent noise temperature and efficiency, impedance matching to minimize front end noise, and beamforming and calibration algorithms for phased array feeds.
21 citations
02 Mar 2009
TL;DR: In this article, the authors revisited the differential probe method to measure the input impedance of balanced antennas and provided simulation results for center-fed and offset-fed dipoles, electrically small antennas and RFID tags.
Abstract: This paper revisits the differential probe method to measure the input impedance of balanced antennas. The differential probe method has been described briefly and it has been applied for various types of antennas. Measurement and simulation results have been provided for center-fed and offset-fed dipoles, electrically small antennas, and RFID tags.
20 citations
02 Mar 2009
TL;DR: In this paper, a composite right/left-handed transmission line (CRLH TL) is used as a parasitic element and it is shown that a right-handed (RH) dipole antenna with the CRLH parasitic element has band rejection characteristics.
Abstract: In this study, a composite right-/left-handed transmission line (CRLH TL) is used as a parasitic element It is shown that a right-handed (RH) dipole antenna with the CRLH parasitic element has band rejection characteristics Moreover, transmission characteristics and electric field distribution confirm that mutual coupling between the two dipole antennas can be reduced by using CRLH parasitic elements between the two antennas
19 citations
02 Mar 2009
TL;DR: In this article, a 24/60 GHz dual-band millimeter-wave on-chip antenna fabricated in TSMC 0.13-μm CMOS process is presented.
Abstract: A 24 / 60GHz dual-band millimeter-wave on-chip antenna fabricated in TSMC 0.13-μm CMOS process is presented here. We design the feeding network by using the coplanar waveguide (CPW) structure. For the dual-band design, there are two major current paths to radiate. To avoid the harmonic frequency band of the low frequency-band, we add two strips to couple the harmonic frequency of the low frequency-band. Besides, the two strips let the higher frequency-band performance better. At this work, the simulator is based 3-D full-wave EM solver, Ansoft HFSS. The on-chip antenna size is 0.76 X 1.045 mm2. The bandwidth of the lower band and higher is about 180MHz and 700MHz, respectively. The simulated gain is about −9dB for 24GHz and about 1dB for 60GHz
18 citations
02 Mar 2009
TL;DR: In this article, a stacked-patch antenna with a switched propagation mode for body-centric communications at 2.45 GHz was proposed, which achieved an efficiency of 62% and an impedance bandwidth of 70 MHz.
Abstract: The ability to electronically switch between off-body and on-body communications is a useful feature for wearable antenna applications. Therefore, we present a novel stacked-patch antenna with a switched propagation mode for body-centric communications at 2.45 GHz. Mounted 2 mm above a muscle-tissue phantom and in the on-body mode, the proposed single-port antenna had an efficiency of 62% and an impedance bandwidth of 70 MHz. The antenna performance increased in the off-body mode with an efficiency of 80% and an impedance bandwidth of 247 MHz. In terms of on-body coupling in anechoic conditions, peak |S21| path gains of −39.6 dB and −48.0 dB were obtained for the on-body and off-body configurations, respectively. These results clearly demonstrate the mode isolation obtained.
17 citations
02 Mar 2009
TL;DR: In this paper, two novel ultra-wideband (UWB) antenna designs based on Composite Right-Left Handed (CRLH) Metamaterial (MTM) structures are elaborated.
Abstract: In this paper, two novel ultra-wideband (UWB) antenna designs based on Composite Right-Left Handed (CRLH) Metamaterial (MTM) structures are elaborated. With CRLH MTM technology embedded, the proposed UWB antenna designs present best in class radiation bandwidth, efficiency, radiation pattern and polarization. All great figures of merits have been achieved based on ultra compact sized PCB antenna structures with convenient integration solution.
17 citations
02 Mar 2009
TL;DR: In this paper, a compact directional coupler based on substrate integrated waveguide is proposed, which consists of two narrow apertures on the common broadside wall of two adjacent SIWs and four microstrip stepwise impedance convertors.
Abstract: A compact directional coupler based on substrate integrated waveguide is proposed. This coupler consists of two narrow apertures on the common broadside wall of two adjacent SIWs and four microstrip stepwise impedance convertors. Attractive features including compact size and planar form make this coupler structure easily integrated in antenna beam-forming networks. A coupler operating at Ka-band is designed. The coupling is about 7 dB at 31GHz, the isolation is below 18dB over the frequency range of 30.55–31.2 GHz, and the return loss is better than 10dB from 30.3 to 31.4 GHz. Design considerations and results are discussed and presented.
02 Mar 2009
TL;DR: In this paper, a Fabry-Perot cavity (FPC) was used to design a 60 GHz single-feed directive antenna, which is made by a ground plane covered by a frequency selective surface (FSS).
Abstract: In this paper a Fabry-Perot cavity (FPC) has been used to design a 60 GHz single feed directive antenna. The FPC antenna is made by a ground plane covered by a frequency selective surface (FSS). We have provided simple design guidelines based on a transmission line model. Numerical simulations confirm the design guidelines and antenna performances.
02 Mar 2009
TL;DR: In this article, the authors discuss the details surrounding the measurement of electrically small antennas, common errors in measurements, and the implications of these errors on system performance, and examine issues of small ground planes, cable effects, and efficiency measurements for their apparent and interrelated effects on input impedance, radiation patterns and system performance.
Abstract: This paper discusses the details surrounding the measurement of electrically small antennas, common errors in measurements, and the implications of these errors on system performance. Issues of small ground planes, cable effects, and efficiency measurements are examined for their apparent and interrelated effects on input impedance, radiation patterns, and system performance.
02 Mar 2009
TL;DR: Depending on the user interaction case, the MIMO capacity of the prototype is between 40–90% at 850 MHz and 60–80% at 2100 MHz higher than the SISO performance of the single antenna prototype or the best antenna on the dual antenna prototype.
Abstract: This paper presents an evaluation of single input single output (SISO), single input multiple output (SIMO) and multiple input multiple output (MIMO) channel capacities for a dual antenna prototype in proximity of a user. The dual antenna prototype mimics today's small mobile phone design in size and in comprising internal, compact, multi-band antennas. Four different user cases are evaluated by measuring the antenna radiation performance for each of the different interactions between a phantom user and the antenna. Measurements of a single antenna prototype with user are also performed for comparisons between the SISO case and the SIMO/MIMO cases. Depending on the user interaction case, the MIMO capacity of the prototype is between 40–90% at 850 MHz and 60–80% at 2100 MHz higher than the SISO performance of the single antenna prototype or the best antenna on the dual antenna prototype.
02 Mar 2009
TL;DR: In this article, a loop-loaded dipole that combines the impedance and radiation characteristics of a small dipole and a small loop on a printed circuit board is proposed for a self-resonating 0.1λ antenna prototype with 3.8dB maximum gain deviation in the full space.
Abstract: A loop-loaded dipole that combines the impedance and radiation characteristics of a small dipole and a small loop on a printed circuit board is proposed. Simulation shows a near-isotropic radiation pattern from a self-resonating 0.1λ antenna prototype with 3.8dB maximum gain deviation in the full space.
02 Mar 2009
TL;DR: In this paper, a small multi-band compact antenna is presented, which has wide impedance bandwidth at 1.2, 1.6, 2.4 and 2.6 GHz with Gain 4.72% at the center of 1.4 GHz.
Abstract: A small multi-band compact antenna is presented. The antenna is designed on Roger RT/duroid 5880 with dielectric constant 2.2, multi-band operations is achieved by inserting a slot on the top patch. The antenna has wide impedance bandwidth at 1.2, 1.6, 2.4 and 2.6 GHz with Gain 4.2, 1, 5 and 2 dBi respectively. The bandwidth before adding the shorting wall and the slot was 3.72%, whereas after adding the shorting wall and the slot the bandwidth get wider to 31.9% at the centre of 1.4 GHz. The radiation pattern has acceptable response with low cross polarization at both E-plane and H-plane. The overall dimension of the ground plane is 70 X 70 X 1.5 mm.
02 Mar 2009
TL;DR: In this article, a two-element diversity-antenna array using epsilon negative zeroth order resonator (ENG-ZOR) at the long-term evolution (LTE) and Wibro (WiMax in Korea) bands for the multiple-input multiple-output (MIMO) application is proposed.
Abstract: We propose a two-element diversity-antenna array using epsilon negative zeroth order resonator (ENG-ZOR) at the long-term evolution (LTE) and Wibro (WiMax in Korea) bands for the multiple-input multiple-output (MIMO) application. Each element is designed by utilizing an ENG ZOR unit cell with size of 10 mm × 6 mm × 6 mm. The lower resonant frequency is fixed by the zeroth order resonance of the ENG ZOR and the higher is selected by the radiator utilizing the first order resonance of the ENG ZOR. An isolator is added between the two elements in order to enhance the isolation characteristic at higher band of the designed MIMO antenna. The MIMO antenna is fabricated on the top side of the ground plane with size of 48 mm × 108 mm × 0.4 mm. The fabricated antenna has the isolation of about 20 dB at the lower band and higher than 13 dB at the higher band.
02 Mar 2009
TL;DR: In this paper, small sinusoidal printed monopoles as enhanced meander-line antennas shaped after smooth curves were designed at 2-3 GHz according to the size and bandwidth constraints of multimedia sensor networks.
Abstract: We present small sinusoidal printed monopoles as enhanced meander-line antennas shaped after smooth curves. The antennas were designed at 2–3 GHz according to the size and bandwidth constraints of multimedia sensor networks. Their performance was characterized in terms of electrical size, bandwidth, and broadband radiation efficiency. A suitable scalar quantity was used to capture the overall performance. Results show that the sinusoidal monopole achieves 68% more bandwidth compared to a meander-line antenna of similar size and efficiency. Antenna performance depends heavily on electrical size, which depends on the size of the ground plane; its effect on radiation was also studied.
02 Mar 2009
TL;DR: In this paper, a design strategy using Photonic Band Gap (PBG) structure on ground plane to achieve wider bandwidth for patch antenna is presented, the impedance bandwidth has improved from 3.72% to 31.9% at centre frequency 9 GHz after adding PBG on the ground plane.
Abstract: A design strategy using Photonic Band Gap (PBG) structure on ground plane to achieve wider bandwidth for patch antenna is presented. It is found that, the impedance bandwidth has improved from 3.72% to 31.9 % at centre frequency 9 GHz after adding PBG on the ground plane. The antenna has multi band operations at 5, 6 and 9 GHz. E-Plane and H-plane radiation patter is satisfied within this bands.
02 Mar 2009
TL;DR: In this article, a novel antenna structure based on optimized direct feed is presented, which consists of the chassis of a mobile terminal, a feed structure and a matching circuitry, which is cut in two pieces, which are connected with an inductor.
Abstract: A novel antenna structure based on optimized direct feed is presented in this paper. The antenna structure consists of the chassis of a mobile terminal, a feed structure and a matching circuitry. The chassis is cut in two pieces, which are connected with an inductor. The value of the inductor is tuned so that the lowest resonant frequency of the chassis equals the center frequency of the operating band. The feed structure excites very strongly the resonant wavemode of the chassis and thus very large bandwidth is available. The feed structure can be integrated e.g. on the PCB of a mobile terminal and thus the antenna is very low-profile. The antenna structure has been demonstrated with a simulated and measured prototype that covers the GSM850/900 systems.
02 Mar 2009
TL;DR: In this paper, the authors presented a simulated and experimental study of the planar inverted-F antenna (PIFA) which involves the changes in different parameters to observe their effects on the antenna characteristics such as the resonant frequency, impedance bandwidth and radiation pattern.
Abstract: This paper represents a simulated and experimental study of the planar inverted-F antenna (PIFA) It involves the changes in different parameters to observe their effects on the antenna characteristics such as the resonant frequency, impedance bandwidth and radiation pattern It is found that the characteristics are affected by a number of parameters which include dimensions of ground plane, length, width and height of top plate, widths of shorting and feeding plates The characterictics are also affected by the horizontal distance between shorting and feeding plates, the position of feeding plate under the top plate, the distance of shorting plate from one edge of top plate and the distance of PIFA structure from horizontal and vertical edges of ground plane Taking these variables into account, a new empirical formula is proposed These results will be very helpful in designing PIFA
02 Mar 2009
TL;DR: Recent advances on this topic of closely coupled antennas are reviewed, including several existing techniques that may be used to push the boundary further, such that closely spaced antennas can still give good performance.
Abstract: The effective use of multiple antenna systems in compact terminal devices is plagued by the problems of mutual coupling and spatial correlation. Consequently, increasing the number of antennas per unit volume results in rapidly diminishing returns after an upper limit is reached. We review recent advances on this topic of closely coupled antennas, including several existing techniques that may be used to push the boundary further, such that closely spaced antennas can still give good performance. A new approach of decoupling closely spaced antennas is also introduced.
02 Mar 2009
TL;DR: It is shown that the application of a PIFA configuration to dual-band E-shaped patches gives the freedom of independently tuning two resonances in a very wide frequency range, without affecting the antenna general structure and external dimensions.
Abstract: This paper discusses the potential of E-shaped patches to be used in reconfigurable antennas. It is shown that the application of a PIFA configuration to dual-band E-shaped patches gives the freedom of independently tuning two resonances in a very wide frequency range, without affecting the antenna general structure and external dimensions. An application of these features to reconfigurable quasi-omnidirectional back-to-back E-shaped patch for laptops is demonstrated. To prove the concept a very simple model of RF MEMS switches is used in a dual-band laptop reconfigurable antenna prototype. In spite of frequency bands toggling (between IEEE 802.11b/g /2.44 GHz/ or WiMAX /3.45 GHz/ and IEEE 802.11a /5.25 GHz or 5.775 GHz/) the radiation pattern is always almost omnidirectional.
02 Mar 2009
TL;DR: In this paper, highly selective filters based on periodic arrays of electrically small resonators are pointed out, which exhibit a composite right/left handed (CRLH) behavior and, by properly tuning the geometry of the elements, a high pass response with a sharp transition band is obtained.
Abstract: In this work, highly selective filters based on periodic arrays of electrically small resonators are pointed out. The high-pass filters are implemented in microstrip technology by etching complementary split ring resonators (CSRRs), or complementary spiral resonators (CSRs), in the ground plane, and series capacitive gaps, or interdigital capacitors, in the signal strip. The structure exhibits a composite right/left handed (CRLH) behavior and, by properly tuning the geometry of the elements, a high pass response with a sharp transition band is obtained. The low-pass filters, also implemented in microstrip technology, are designed by cascading open complementary split ring resonators (OCSRRs) in the signal strip. These low pass filters do also exhibit a narrow transition band. The high selectivity of these microwave filters is due to the presence of a transmission zero. Since the resonant elements are small, filter dimensions are compact. Several prototype device examples are reported in this paper.
02 Mar 2009
TL;DR: In this article, a dual-band circular polarization (CP) monopole antenna was proposed to generate a broadband impedance-bandwidth from 2.17 to 8.47 GHz and excite a left-hand circular polarization at 2.48 GHz and right-hand linear polarization (RHCP) at 3.90 GHz.
Abstract: This paper proposes a dual-band circular polarization (CP) monopole antenna. This antenna can generate a broadband impedance-bandwidth from 2.17 to 8.47 GHz, and excite a left-hand circular polarization (LHCP) at 2.48 GHz and right-hand circular polarization (RHCP) at 3.90 GHz. The measured 3-dB axial ratio (AR) bandwidths are about 140 MHz from 2.41 to 2.55 GHz approximately 5.6% with respect to the center frequency at 2.48 GHz and 900 MHz from 3.45 to 4.35 GHz approximately 23.1% with respect to the center frequency at 3.90 GHz.
02 Mar 2009
TL;DR: In this article, complementary split ring resonator (CSRR) array is realized on the ground plane along the length of a rectangular microstrip antenna (RMSA) that improves the realized gain by providing better match at the desired resonant frequency.
Abstract: In this paper complementary split ring resonator (CSRR) array are realized on the ground plane along the length of a rectangular microstrip antenna (RMSA) that improves the realized gain by providing better match at the desired resonant frequency. Dual band operation is also observed when the array of CSRR designed at double the RMSA resonant frequency is inserted half way underneath the patch.
02 Mar 2009
TL;DR: It has been shown that a coupling element in combination with a configurable tuning circuit can be used to excite the chassis of the mobile terminal to act as the entire antenna in many different frequency bands.
Abstract: Some key aspects of two different concepts of configurable antennas for future mobile terminal have been addressed in this paper. It has been shown that a coupling element in combination with a configurable tuning circuit can be used to excite the chassis of the mobile terminal to act as the entire antenna in many different frequency bands. However, when both the coupling element and the tuneable circuit elements are combined in a compact LTCC antenna component the achievable antenna efficiency is quite weak.
02 Mar 2009
TL;DR: In this paper, a left-handed metamaterial structure incorporated with a single microstrip patch antenna at 2.7 GHz was designed and simulated with the combination of the modified square rectangular split ring (SRR) and the capacitance loaded strip (CLS) to obtain the negative value of permeability, μ and the negative permittivity.
Abstract: The scope of this project was to design and simulate left-handed metamaterial structure incorporated with a single microstrip patch antenna at 2.7 GHz. The combination of the modified square rectangular split ring (SRR) and the capacitance loaded strip (CLS) was used to obtain the negative value of permeability, μ and the negative permittivity, e. From the simulation and fabrication done, the gain of the antenna has been increased up to 4 dB. This had proven that the LH MTM can enhance the gain of the antenna.
02 Mar 2009
TL;DR: In this paper, the matching properties of coaxial cables in ultranarrow channels with zero permittivity metamaterials were explored and a simple matching design, valid for arbitrary waveguides with large degrees of freedom in terms of geometry, length and possible bending of the connecting channel was proposed.
Abstract: Here we explore the matching properties of coaxial cables in ultranarrow channels filled with zero permittivity metamaterials. We discuss how the anomalous properties of such channels may allow a simple matching design, valid for arbitrary waveguides, with large degrees of freedom in terms of geometry, length and possible bending of the connecting channel. Moreover, the static-like properties of the channel may allow complete matching, independent of the relative position of the antenna inside the channel. We propose a simple verification of these concepts in rectangular channels operating at cut-off, which realize a simple and powerful mechanism for achieving effective permittivity near zero in this geometry. Our findings may constitute an elegant and powerful method for matching coaxial antennas to waveguides of arbitrary shape and geometry.
02 Mar 2009
TL;DR: In this paper, a MIMO antenna design optimization method based on minimization of correlation coefficients for maximizing the system capacity in multiple-input multiple-output (MIMO) systems is presented.
Abstract: A MIMO antenna design optimization method based on minimization of correlation coefficients for maximizing the system capacity in Multiple-Input Multiple-Output (MIMO) systems is presented. The packaging effects on radiation field patterns of MIMO antenna elements have also been included using a reciprocity approach and Method of Moments (MoM) analysis. As practical examples, optimal location of two patch antennas placed on a small ground plane and conducting cube have been determined using the proposed method.