The following sections discuss first the relevant parameters that characterize the radiation from antennas. Then, a set of frequently employed GPR antennas is briefly presented and explained in terms of these parameters. Finally, taking these geometries as a starting point of any antenna design, some recent GPR antenna designs are presented on the basis of computational optimization techniques. It should also be noted here that the same antennas are used for reception of signals, either using a single antenna for both purposes or separate antennas for transmission and reception. It is not necessary to discuss receiving antenna separately because, based on the reciprocity principle, the parameters are the same, that is, the basic electric properties such as impedance, bandwidth, efficiency, and radiation pattern are the same for both functions. The obvious difference is in the power levels but since antennas are typically very efficient, power radiated has little effect on the structure of the antenna.
Chapter Contents:
- 3.1 Introduction
- 3.2 Antenna radiation parameters
- 3.2.1 Radiated power
- 3.2.2 Antenna radiation patterns
- 3.2.2.1 Antenna field radiation patterns
- 3.2.2.2 Antenna power radiation pattern
- 3.2.2.3 Beamwidth
- 3.2.3 Radiation intensity
- 3.2.4 Antenna directivity
- 3.2.5 Antenna gain
- 3.2.6 Polarization
- 3.2.7 Radiation resistance
- 3.2.8 Input impedance
- 3.2.9 Bandwidth
- 3.2.10 Pulse fidelity
- 3.2.11 Group delay
- 3.2.12 Receiving antenna parameters
- 3.2.13 Effective aperture
- 3.2.14 Antenna footprint
- 3.3 Antenna interaction with the medium under test
- 3.4 Antenna types for ground penetrating radar
- 3.4.1 Dipole antennas
- 3.4.2 Bowtie antennas
- 3.4.3 Vivaldi antennas
- 3.4.4 Spiral antennas
- 3.4.5 Horn antennas
- 3.4.6 Antenna arrays
- 3.5 Antenna design for GPR systems
- 3.5.1 GPR system parameters
- 3.5.1.1 Waveforms
- 3.5.1.2 System bandwidth
- 3.5.1.3 Antenna position
- 3.5.1.4 Legislation and standards
- 3.5.2 GPR antenna optimization framework
- 3.5.2.1 The electromagnetic model
- 3.5.2.2 GPR antenna optimization goals
- 3.6 The optimization process
- 3.6.1 The multi-objective genetic algorithm
- 3.6.2 Examples of optimization
- 3.6.2.1 Rounded bowtie antenna
- 3.6.2.2 Archimedean spiral antenna
- 3.6.2.3 Equiangular spiral antenna
- 3.6.2.4 Vivaldi antenna
- 3.6.2.5 U-slot patch antenna
- 3.6.3 Optimization for specific applications
- 3.6.3.1 Planar bowtie antenna optimization
- 3.6.3.2 V-shaped bowtie antenna optimization
- 3.6.3.3 Some remarks on optimization
- References
Inspec keywords:
receiving antennas;
optimisation;
radar antennas;
antenna radiation patterns;
ground penetrating radar
Other keywords:
reciprocity principle;
antenna design;
receiving antenna;
GPR antennas;
radiation pattern;
ground penetrating radar;
electric properties;
computational optimization techniques
Subjects:
Radar equipment, systems and applications;
Single antennas;
Optimisation techniques