Abstract-A wideband antenna is designed based on the concept of equivalent magnetic dipole and electric dipole combinations with excellent radiation characteristics. Single linear polarization design with two different excitations achieves good radiation symmetry and low cross-polarization. The dual-polarization case has a 67% bandwidth and isolation better than 30 dB. The present design and construction of the antenna provides simple solutions compared with similar antennas in the literature. This design avoids loading the antenna with dielectric in the active region. The agreement between measured and simulated results is excellent. The suggested antenna construction is very simple and solves many of the problems related to the practical excitation of this antenna.
A Huygens source principle is used to design a wideband antenna. An electric dipole and a slot are located above a ground plane to have unidirectional broadside radiation with high front to back ratio. A symmetry radiation patterns are obtained. Linear and dual polarized antennas are designed and tested. The antennas achieve more than 50% bandwidth for both cases. The dually polarized antenna achieves around 30 dB isolation between the two ports.
This paper presents a method for calculating the site attenuation (SA) of an open-area test site (OATS) for a pair of calculable dipole antennas with a 3-dB hybrid balun in the frequency range of 30 MHz to 1 GHz. The SA was directly derived using the concept of power mismatch and dissipative loss from the SA measurement system instead of the concept of substitution loss. Two types of SA formulas using the power loss concept on the treatment of the OATS are presented. The first is the SA formula related to knowing only the value of the SA. The other is the SA formula that analyzed the effects of each part of the SA. Additionally, the constituent losses of the SA measurement system are discussed using the derived SA formula. The analysis of the results showed that the SA could be successfully characterized individually from the loss of the OATS. It also showed that SA is expressed as two kinds of losses: the balanced portmismatch losses of transmit and receive baluns and the half-space dissipative loss. The resultant SA showed good agreement with the results calculated from the S-parameters as well as with the measured results.
When a pair of calculable dipole antennas (CalDAs) with a 3-dB hybrid balun is used for a validation test of a constructed open area test site (OATS), the theoretical normalized site attenuation (NSA) curves of an ideal OATS for the CalDAs are required. This paper presents a method to calculate this theoretical NSA in the frequency range of 30 MHz to 1 GHz. The theoretical NSA was directly derived using the power mismatch and dissipative loss concepts of an NSA measurement system. Accurate antenna factors (AFs) above the ground plane were also needed and calculated to obtain the theoretical NSA. When free-space AFs are used to determine the measured NSA, AF correction factors known as mutual impedance correction factors are needed. Both free-space AFs and AF correction factors were also considered.
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