End‐fed modified planar dipole antenna for DTV signal reception

Abstract

In this study, we presented and applied a focusing method based on hyperbolic summation (HS) technique to the simulated and measured B-scan GPR data generated via a SFR system, especially tested at C-band frequencies. The methodology was explained in detail and both numerical and measured examples, testing the effectiveness of the method, were presented. Application of the proposed method to the examples demonstrated that pipes and point scatterer-like objects produce very well-focused images in the new GPR image. This is due to the fact that the method uses hyperbolic templates corresponding to point-scatterers and converts these hyperbolas to single image pixels. The plate-like objects in the numerical examples also successfully produced wellfocused images. In terms of computational efficiency, the algorithm is fast for 2-D B-scan images. It is clear that, the method can easily be adapted to 3-D C-scan images with hyperbolic surface templates. The method is examined with an SFR experimental set-up and measured B-scan GPR data. Both the traditional and the focused B-scan images were generated after applying the proposed method. Acceptable success has been achieved for the measured data as well.The main weakness of the method becomes apparent for the case if any scattering mechanism falls under the hyperbolic template of another greater scattering, this point will produce a smaller scattering than its original EM energy in the final GPR image. Therefore, the energy levels in the final focused image will not correspond to the true energy levels of each scatterer. The other drawback of the method is that it produces ghost tails from the focused point toward upper regions as explained in Section 4. This phenomenon can be observed from Figure 5(b).In this work, we only considered homogeneous and nearly lossless mediums. For inhomogeneous, lossy, and anisotropic mediums, the applicability of the method would be limited as the velocity and the wave number of the EM wave changes as the wave travels. Therefore, a model-based focusing method should be adopted for such soils.

A Compact Dipole Antenna for DTV Applications by Utilizing L-Shaped Stub and Coupling Strip

“…Microstrip dipole antennas have attracted much attention because of broad bandwidth, easy impedance matching, small size, and light weight [2]- [6]. With a step-shaped gap inside the antenna structure, the printed dipole antenna has been comprehensively investigated for the DTV signal reception [2].…”

Printed Dipole Antenna With Back to Back Asymmetric Dual-C-Shape Uniform Strips for DTV Applications

“…For this reason, a simple antenna as a transducer between the DTV transceiver and the propagating medium is much desirable if it could operate at DTV bands. Planar printed antennas include broadband dipole [1,2] and broadband monopole antennas [3][4][5]. On account of horizontally polarized DTV signals, the horizontally oriented antenna is a very promising candidate for DTV signal reception, and desirable radiation patterns for devices are usually omni-directional, therefore, a dipole antenna could be expected.…”

Wideband Rod-Dipole Antenna With a Modified Feed for DTV Signal Reception

“…The DTV reception is becoming an alluring feature for applications to mobile devices, such as laptops and mobile phones, and vehicles. Several standalone DTV antennas have been reported [1][2][3][4], and each of them has its merits. A folded dipole antenna with stubs to cover the upper-edge frequency at 710 MHz is studied in [1] as vehicle antennas.…”

“…In [2], an earpiece cord is utilized as the DTV antenna for mobile-phone end users. Two asymmetrical dipole antennas with a step-shaped [3] and an L-shaped [4] feed gaps for DTV reception in the 470-806 MHz band are demonstrated. The broadband operation in [3,4] is obtained by combining the onewavelength and half-wavelength resonant modes.…”

“…Two asymmetrical dipole antennas with a step-shaped [3] and an L-shaped [4] feed gaps for DTV reception in the 470-806 MHz band are demonstrated. The broadband operation in [3,4] is obtained by combining the onewavelength and half-wavelength resonant modes. These promising designs, however, can not cover the entire 470-862-MHz UHF band of broadcast TV channels in most regions of the world [5], which are usually required by specifications in industry.…”