Dipole Patch Research Articles

Compact K/Ka‐band dipole antenna element with ball grid array packaging

AbstractA compact K/Ka‐Band dipole antenna element with ball grid array packaging is proposed. The antenna is divided into two parts, one is a cuboid antenna element fabricated on a FR4 printed circuit board, and the other is a grounded coplanar waveguide feed line fabricated on a motherboard. To minimize the size of the antenna element, we use three‐dimensional structure to design the antenna element. The dipole patches are fabricated on the top layer of the antenna element, and the ball grid array is on the bottom layer of the antenna element. Plated through holes connect solder balls and dipole patches. Finally, the antenna element is mounted on the motherboard. We designed, manufactured and measured the antenna prototypes. The details of the antenna design and the measurement results are presented and discussed.

Low-Profile Broadband Magnetoelectric (ME) Dipole Antenna with Dual-Complementary Source

In this letter, a magnetoelectric (ME) dipole antenna with low profile, broadband, stable unidirectional radiation is presented. Traditional Γ-shaped feeding structure is shunted, improved, and hence a dual-magnetic dipole is formed. Furthermore, a dual-electric dipole is also formed by etching a slot on top electric dipole patch. Therefore, an ME dipole antenna with a dual-complementary source is achieved by combining both of dual-magnetic dipole and dual-electric dipole element and has a very lower profile of 0.079λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> (λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> is the free-space wavelength of center frequency). Additionally, the working principle is analyzed by discussing the surface current of this dual-complementary source ME dipole. The electric dipole and magnetic dipole work alternatively in one period of time domain. By measurement, the relative impedance bandwidth is 46.2% (from 2.45 to 3.92 GHz) for VSWR<; 2. Boresight gain ranges from 6.98 to 10.19 dBi in its impedance bandwidth. A low crossed polarization is also obtained. By comparison with other works, the proposed antenna has an advantage in broadband and height-saved applications.

Dual-Polarized Broadband Base Station Antenna Backed With Dielectric Cavity for 5G Communications

A compact dual-polarized antenna with total dimensions of 31 × 31 × 14 mm3 is proposed for the fifth-generation base stations at 3.5 GHz. The antenna consists of two orthogonal bow-tie dipoles. The bandwidth is enhanced using eight parasitic strips along with the dipole patches, two U-shaped slots around the feeding positions, and dielectric cavity, which brings two resonant frequencies closer to each other. The isolation between the dual polarization is improved by adding two shorting pins symmetrically with respect to the feeding cable. The proposed antenna operates in the range of 3.2–3.9 GHz with S11 ≤−15 dB and has port isolation better than 40 dB. The measured results show good performances in front-to-back ratio, cross-polarization discrimination ratio, and stable radiation patterns. Finally, the proposed antenna is used to construct a 2 × 4 multiple-input–multiple-output (MIMO) antenna with a compact size of 101 × 170 × 14 mm3 (1.16 λ 0 × 1.96 λ 0 × 0.16 λ 0). The MIMO antenna is fabricated and tested. Good results are observed.

Multiresonance Chipless RFID Sensor Tag for Metal Defect Characterization Using Principal Component Analysis

One of the challenges in structural health monitoring (SHM) is that defects, such as metal cracks and corrosions, can occur with multiple material properties and multilayer structure, entangled with influences from the reader system and the environment. This paper presents a multiresonance chipless radio frequency identification (RFID) sensor tag and the chipless RFID sensor reader applying principal component analysis (PCA) for multiparameter estimation in metal defect characterization. The proposed sensor tag is composed of the crossed diagonal dipole patches and the L-shaped patches generating six resonance peaks within 2-6-GHz band. The frequency signature of the sensor tag is acquired and processed by a chipless RFID reader implemented using an ultra-wideband impulse radar (UWB-IR) transceiver module. We demonstrate that the multiresonance chipless RFID sensor tag in conjunction with PCA-based feature extraction and selection can be applied for the characterization of metal crack with different widths and orientations. Furthermore, the proposed technique can find a robust feature indicating corrosion stages under a coating layer regardless of the sample orientation. This paper paves the way for multiparameter defect sensing and monitoring using a chipless RFID sensor system.

An umbrella‐shaped broadband circularly polarized antenna with wide beamwidth for global navigation satellite systems applications

AbstractA novel umbrella‐shaped wideband circular polarization (CP) antenna with a wide half‐power beamwidth (HPBW) and a wide axial ratio (AR) bandwidth is proposed in this article. Two pairs of symmetrical patch dipoles are attached to the surface of an umbrella‐shaped substrate to broaden both the impedance bandwidth (IBW) and the HPBW. A parasitic metallic ring is located immediately above the umbrella substrate to provide further enhancement of the HPBW. Each patch dipole is excited via a coaxial line, while a conductor balun with length of λ0/4 (where λ0 is the wavelength of the center frequency) is introduced to obtain a feeding balance. Measurement results indicate that the proposed antenna has a −10 dB IBW of 71.3% (from 1.03 to 2.17 GHz), and a 3 dB AR bandwidth of 55.6% (from 1.13 to 2.0 GHz). Additionally, an HPBW of more than 110° is obtained over the whole CP bandwidth, 48.2% of which has an HPBW of more than 120°. The antenna has dimensions of 100 × 100 × 28 mm3, which corresponds to (0.52 × 0.52 × 0.14)λ03.

Finite-Element Computation of Antenna Impedance Frequency Response Considering Finite Conductivity

Finite-element techniques are applied to the frequency response computation of the input impedance of antennas with the eddy current losses taken into account. Both time-domain and frequency-domain approaches are discussed. Comparison to results for a dipole patch antenna with T-match obtained by assuming infinite conductivity is presented.

A Dual-Band Shared Aperture Antenna Array in Ku/Ka-Bands for Beam Scanning Applications

A dual-band shared aperture antenna array for phased array system operated in Ku/Ka-bands is proposed in this paper. By judiciously designing the geometrical structure and parameters, compact and integrated antenna elements are proposed to achieve the maximum scanning angle without the grating lobes phenomenon. The patch-dipole antenna elements operating in Ku-band and microstrip patch antenna elements operating in Ka-band are designed and fabricated utilizing a four-layer lamination substrate. Metal shielding vias are introduced to suppress the coupling between the antenna elements operating in different bands, meanwhile, defected ground structure is introduced to eliminate the scan blindness effect and improve the beam scanning range effectively. The proposed antenna array has 208 Ku-band elements and 832 Ka-band elements distributed in the shared aperture with a diameter of 200 mm. Measured results show that the proposed antenna array has a broad impedance bandwidth of 10.7% in Ku-band and 9.1% in Ka-band, meanwhile it has a relatively wide scanning angle ranging from -45° to +45° with low gain decrease and side lobe level. The proposed phased array antenna has potential application in a radar system, mobile communication system, and so on.

A highly directive graphene antenna embedded inside a Fabry-Perot cavity in terahertz regime

In this paper, a highly directive nano-thickness graphene-based antenna is introduced in the terahertz frequency band. The antenna is a graphene patch dipole which is placed between two Bragg mirrors called Fabry-Perot cavity. Tunability of the graphene's conductivity makes it possible to excite the desired resonances of the cavity. Here, first, a single resonant antenna is introduced at 5 THz with an enhanced gain from 2.11 dBi to 12.8 dBi with a beamwidth of 22.7°. Then, a triple resonant antenna at 4.7, 5 and 5.3 THz is presented with respective gains of 7.97, 11.9 and 8.52 dBi. Finally, the effect of dimensions and number of the dielectric layers of the cavity are studied in order to further increase in directivity.

An MEMS Phase Shifter With High Power Handling for Electronic Beam Tilt in Base Station Antennas

This letter presents the implementation of RF MEMS-based phase shifter with high power handling capabilities (measured IP3 >63 dBm), high phase, and amplitude linearity (measured rms deviation $\times $ 2 array of angled dipole patch antennas is designed and fabricated and four different scans are successfully measured showing a maximum deviation of ±0.6° only for the scan angle.

A Design of LPDA Antenna with Patch Dipoles for Airbone Communication

This article designs a Log-periodic Dipole Antenna(LPDA) for airborne communication. This antenna replaces traditional dipoles with patch dipoles, the feeder adopt gradual changing structure, its working frequency is from 200MHz to 450MHz.Use HFSS which is the special software for high-frequency electromagnetic to calculate, optimize and simulate. The simulation rsults are in good agreement with the test results. The designed antenna improves its flexibility and reduces profile, it provide a good method for the design of the airborne antenna.

Design of high gain and wide band EBG resonator antenna with dual layers of same dielectric superstrate at X-bands

A wide band EBG resonator antenna with two layer of dielectric superstrates of the same material is design which is operating in X band. The EBG superstrates act as Partially Reflective Surfaces (PRS) having positive reflection phase curve which are suspended above a double sided dipole patch antenna fed by a coaxial cable pass through ground plane. Thus a resonator cavity is constructed which increases the bandwidth and gain of the feed antenna. The measured results validate the simulation results obtain from Computer Simulation Technology (CST) microwave studio. These results show that the antenna posses a 3 dB gain bandwidth from 8.5 GHz to 11.2 GHz, with a peak gain of 15.3 dBi. Furthermore, the scattering parameter S11 is well within range from 8.6 GHz to 11 GHz.

Low Radar Cross Section and Broadband Magneto-electric Dipole Patch Antenna

A low Radar Cross Section (RCS) and broadband Magneto-Electric (ME) dipole patch antenna from 7.81 GHz to 13.65 GHz covering the whole X band is designed and fabricated. Metal patches printed on the substrate form the electric dipoles, three metallic vias connected to the radiation patches and the metal ground account for the magnetic dipole radiation. The whole antenna is connected with a T-shaped feed structure which excites electric and magnetic dipoles simultaneously. Numerical and experimental results incident that the RCS of the ME dipole patch antenna can be reduced in the whole bandwidth which the largest value is up to 17.9 dB by cutting slots on the ground and optimizing the size, shape, position of the slots. Also, the antenna shows advanced performances such as stable gain and almost consistent pattern in E and H plane.

Ti:LiNbO&lt;sub&gt;3&lt;/sub&gt; Y-fed Balanced-Bridge 마하젠더 간섭 광변조기를 이용한 집적광학 전계센서에 관한 연구

We have demonstrated a electro-optic electric-field sensors utilizing a Y-fed balanced-bridge Mach-Zehnder interferometric (YBB-MZI) modulator which uses a 3-dB directional coupler at the output and dipole patch antenna. The operation and design were proved by the BPM simulation. A dc switching voltage of ~16.6 V and an extinction ratio of ~14.7 dB are observed at a wavelength of . For a 20 dBm rf power, the minimum detectable electric-fields are ~1.12 V/m and ~3.3 V/m corresponding to a dynamic range of about ~22 dB and ~18 dB at frequencies 10 MHz and 50 MHz, respectively. The sensors exhibit almost linear response for the applied electric-field intensity from 0.29 V/m to 29.8 V/m.

A COMPACT DUAL-BAND DUAL-POLARIZED ANTENNA FOR BASE STATION APPLICATION

A compact dual-band dual-polarized antenna is proposed in this paper. The two pair dipoles with strong end coupling are used for the lower frequency band, and cross-placed patch dipoles are used for the upper frequency band. The ends of the dipoles for lower frequency band are bent to increase the coupling between adjacent dipoles, which can benefit the compactness and bandwidth of the antenna. Breaches are introduced at the ends of the dipoles of the upper band, which also benefit the compactness and matching of the antenna. An antenna prototype was fabricated and measured. The measured results show that the antenna can cover from 790MHz to 960MHz (19.4%) for lower band and from 1710MHz to 2170MHz (23.7%) for upper band with VSWR < 1.5. It is expected to be a good candidate design for base station antennas.

1 × 2 wideband patch‐dipole antenna array with slot coupler

A 1 × 2 wideband patch-dipole antenna array is proposed, which consists of a slot coupler, a cavity and two pairs of bow-tie dipole antennas loaded with meandering loops. The slot coupler has two functions: one is to work as a divider and the other is to generate differential signals for bow-tie dipole antennas. Each bow-tie dipole antenna is conveniently and differentially fed by two parallel probes located symmetrically at both sides of the slot coupler. A prototype is fabricated and measured for verification. The experimental results show that the proposed antenna array achieves a bandwidth of 66.4% ranging from 1.59 to 3.17 GHz. Stable radiation patterns with low cross-polarisation and a flat gain fluctuating in the range of 10.2 ± 1.5 dBi are found over the whole frequency band.

A bioinspired hybrid optimization algorithm for designing broadband frequency selective surfaces

ABSTRACTA hybrid optimization technique is used to synthesize frequency selective surface (FSS) structures composed of periodic arrays of integrated rings and dipole patch elements, printed on dielectric substrates, for microwave filtering applications. The optimization technique is based on the combination of genetic algorithms and neural networks. This hybrid optimization technique is used to determine specific values for the resonant frequency and bandwidth from variations of the FSS structural parameters, such as patch element and periodic array dimensions. The synthesized FSS structure is also analyzed using a fast and accurate wave concept iterative procedure for comparison purpose. Thereafter, prototypes are built and measured. A good agreement is observed between simulated and measured results. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:329–333, 2014

Dual-polarized patch antenna with high isolation for DTV applications

In this paper, the design, simulation results, and measurements of a coaxial-fed dual-polarized patch antenna with high port isolation are presented. The proposed antenna consists of two cross center-fed patch dipole antennas against a reflector as ground plane, while the patch antenna contains two pairs of X-shaped slots along the diagonals and two pairs of T-shaped slots along the centerlines. The proposed antenna achieves a -10 dB with bandwidth of 470–730 MHz and demonstrates the dual polarization in both directions. Stable radiation patterns at slanted polarization have been obtained within the band. Measurements show two linear polarizations with an isolation of more than 33 dB over the operating frequency band. The proposed antenna can be used for Digital television applications (DTV).

Millimeter-Wave Cavity-Backed Patch-Slot Dipole for Circularly Polarized Radiation

A novel millimeter-wave antenna for circularly polarized (CP) radiation is presented. The proposed antenna is composed of a patch dipole and a slot dipole, and it is realized by a plated through-hole printed technique on a microwave substrate. Measurements show that the antenna can present a bandwidth from 56.2 to 65 GHz for a reflection coefficient S11 ≤ -10 dB as well as for an axial ratio (AR) ≤ 3 dB, and the 10.03-dBi average gain is achieved. This design yields good directional radiation patterns. Studies on several critical parameters are performed for practical designs.

Methods for Examining Electrophysiological Coherence in Epileptic Networks

Epilepsy may reflect a focal abnormality of cerebral tissue, but the generation of seizures typically involves propagation of abnormal activity through cerebral networks. We examined epileptiform discharges (spikes) with dense array electroencephalography (dEEG) in five patients to search for the possible engagement of pathological networks. Source analysis was conducted with individual electrical head models for each patient, including sensor position measurement for registration with MRI with geodesic photogrammetry; tissue segmentation and skull conductivity modeling with an atlas skull warped to each patient’s MRI; cortical surface extraction and tessellation into 1 cm2 equivalent dipole patches; inverse source estimation with either minimum norm or cortical surface Laplacian constraints; and spectral coherence computed among equivalent dipoles aggregated within Brodmann areas with 1 Hz resolution from 1 to 70 Hz. These analyses revealed characteristic source coherence patterns in each patient during the pre-spike, spike, and post-spike intervals. For one patient with both spikes and seizure onset localized to a single temporal lobe, we observed a cluster of apparently abnormal coherences over the involved temporal lobe. For the other patients, there were apparently characteristic coherence patterns associated with the discharges, and in some cases these appeared to reflect abnormal temporal lobe synchronization, but the coherence patterns for these patients were not easily related to an unequivocal epileptogenic zone. In contrast, simple localization of the site of onset of the spike discharge, and/or the site of onset of the seizure, with non-invasive 256 dEEG was useful in predicting the characteristic site of seizure onset for those cases that were verified by intracranial EEG and/or by surgical outcome.

A millimeter-wave resistor-less pulse generator with a new dipole-patch antenna in 65-nm CMOS

This paper presents a millimeter-wave (mm-wave) pulse generator (PG) integrated with a new dipole-patch antenna in a 65-nm CMOS process for short range and portable active imaging applications. The integrated wide-band dipole-patch antenna is a combination of two type of radiators, patch and dipole, to exploit both advantages of the two antenna types. The $$395\hbox{-}{\upmu}\hbox{m}\times 625\hbox{-}{\upmu}\hbox{m}$$ dipole-patch antenna in the top metal layer of the 65-nm CMOS process has a wide 30.2-GHz bandwidth from 73.9 to 104.1 GHz with minimum reflection coefficient of −29 dB at 101.6 GHz and resistance from 27.3 to 47.5 $$\Upomega$$ by simulation in Momentum, ADS 2009. We proposed a resistor-less mm-wave damping PG whose peak-to-peak pulse output is 1.66-V with 9.1-ps duration in HSPICE simulation at the antenna input terminals. Radiation measurements by using a horn antenna and a Schottky diode placed at a 39-mm distance from the chip’s surface show the main beam’s peak at θ max = 17° with a half-power beam-width (HPBW) of 9° and the second beam’s peak at θ sec = −23°. Maximum radiated powers in horizontal and vertical planes are respectively 2.4 and 0.5 μW.