Log-periodic Patch Research Articles

Log-Periodic Patch Array with Coupled T-Probes for Broadband Dual-Polarized Antenna-on-Display

Log-Periodic Patch Array with Coupled T-Probes for Broadband Dual-Polarized Antenna-on-Display

Mathematical analysis for resonant frequencies of a novel 3-element log periodic patch array

Mathematical analysis for resonant frequencies of a novel 3-element log periodic patch array

Log-periodic enactment of a novel patch with square DGS for Ku-band applications

A novel Log periodic patch with a circular slot antenna has been presented here, the perturbation of the shape of the antenna has been done by combining a triangular shape with a semicircular shape. The antenna proposed here is with a DGS structure on its ground plane and its effects on bandwidth and gain enhancement of the antenna are analyzed. The substrate of FR-epoxy material with length, breadth and height 170 mm, 50 mm and 1.6 mm, respectively is taken for implementation of the antenna on it. This proposed antenna operates at 12 GHz to 18 GHz which includes Ku-band with return loss below-10 dB. The parameters of antenna like S-parameters, antenna gain, directivity, VSWR, surface current distribution and radiation efficiency are determined one by one to ascertain its better performance. The simulation as well as the measurement results are comparatively analyzed.

A novel design of a compact wideband patch antenna for sub-6 GHz fifth-generation mobile systems

In this paper, a new broadband patch antenna design for fifth-generation (5G) sub-6 GHz mobile systems is presented. The proposed 5G antenna has a very compact size with an overall dimension of 10.7 × 22.5 mm2. The 5G antenna consists of a log-periodic patch in the form of an equilateral triangle with a 50 Ω microstrip line feed and a ground plane of rectangular shape. The prototype of the proposed 5G antenna was made by etching on an FR4 substrate with a 1.6mm thickness, 4.3 dielectric constant and 0.02 tangent loss. The 5G antenna is designed and simulated for the frequency band range of 3.4-4.2 GHz. According to the measurement results, the 5G antenna impedance band range is determined as 3.1-3.9 GHz. Besides, the proposed 5G antenna has also near-omnidirectional radiation patterns both simulation and measurement at the resonance frequencies of 3.8 GHz and 3.5 GHz, respectively. According to these results, the proposed antenna is showed similar radiation characteristics in both measured and simulated results. With all these radiation and physical properties, the proposed log-periodic patch antenna is very suitable for sub-6 GHz 5G mobile applications.

A Low Profile Wideband Log Periodic Microstrip Antenna Design for C-Band Applications

In this study, a wideband low profile microstrip antenna design for C-band applications is presented. The proposed antenna consists of a monopol log periodic patch in the equilateral triangular dimensions with the microstrip line fed and a rectangular ground plane. The antenna has 9×19.8 mm2 overall size, thickness of 1.6 mm and 4.3 dielectric constant. According to the simulation results, the proposed antenna has a very wide bandwidth while operating in the frequency band of 4.25-7.95 GHz and 5 GHz resonance frequency. The proposed antenna was also prototyped on FR4 substrate with the 0.02 tangent loss and the measurement results were quite similar by the simulated results.

통신 항법용 다중대역 안테나 내장 스킨구조의 지상시험평가

This paper suggests a test and evaluation procedure of conformal load-bearing antenna structure(CLAS) for high speed military jet application. A log periodic patch type antenna was designed for multi-band communication and navigation antenna. Carbon/Glass fiber reinforced polymer was used as a structure supporting aerodynamic loads and honeycomb layer was used to improve antenna performance. Multi-layers were stacked and cured in a hot temperature oven. Gain, VSWR and polarization pattern of CLAS were measured using anechoic chamber within 0.15~2.0 GHz frequency range. Tension, shear, fatigue and impact load test were performed to evaluate structural strength of CLAS. Antenna performance test after every structural strength test was conducted to check the effect of structural test to antenna performance. After the application of new test and evaluation procedure to validate a new CLAS, a design improvement was found.

Frequency reconfigurable log periodic patch array

A novel reconfigurable low profile log periodic patch array is presented. The patches are fed with a modulated meander line through aperture slots. A wideband mode from 7-10-GHz and three selected narrow band modes at 7.1, 8.2, and 9.4-GHz are demonstrated. The wideband to narrow band reconfiguration is realised by bridging the slot aperture, effectively deactivating the corresponding radiating element. Potentially the proposed method offers a very fine control of a narrow passband. Measured and simulated results with very good agreement are presented, thus verifying the proposed concept.

Broadband Microstrip Antennas on Electrically Thick Substrates

Two configurations of broadband microstrip antennas are proposed and analyzed numerically by the full-wave spectral-domain method. One is a square Archimedean spiral microstrip antenna which yields circular polarization; the second configuration is a log-periodic patch microstrip antenna, which radiates linearly. In this paper, the definition of bandwidth of an antenna is redefined and is based on both VSWR and radiation pattern behavior. A 25% bandwidth for a square Archimedean spiral microstrip antenna and a 2:1 bandwidth for a log-periodic patch microstrip antenna are achieved using electrically thick (1/8λ to 1/4λ) substrates.

Bandwidth limitations of log-periodic microstrip patch antenna arrays

Results are presented for the frequency dependence of the propagation constant of uniform microstrip patch arrays that allow the bandwidth limitations of log-periodic patch arrays to be deduced. It is found that direct coupling of the patch to the feed line limits the log-periodic bandwidth to about a 2:1 frequency range. However, the introduction of series reactance into the equivalent circuit such as by the use of overlaid patches indicate that log-periodic action over a very wide bandwidth is possible which will then be limited by the uniform substrate and production tolerances.