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This is a reflector element used to form a 2-element Yagi beam antenna. The wire length for the reflector element is 5% longer than the dipole-driven element positioned above it. The dipole is located at a distance of 0.15 wavelengths above the reflector element.
The 10-meter band was allocated on a worldwide basis by the International Radiotelegraph Conference in Washington, DC, on 4 October 1927. [2] Its frequency allocation was then 28-30 MHz. A 300 kHz segment, from 29.700–30.000 MHz, was removed from the amateur radio allocation in 1947 by the International Radio Conference of Atlantic City.
The beam direction (direction of greatest sensitivity) is to the left. A Yagi–Uda antenna, or simply Yagi antenna, is a directional antenna consisting of two or more parallel resonant antenna elements in an end-fire array; [1] these elements are most often metal rods (or discs) acting as half-wave dipoles. [2]
The first technique developed was the far-field range, where the antenna under test (AUT) is placed in the far-field of a range antenna. Due to the size required to create a far-field range for large antennas, near-field techniques were developed, which allow the measurement of the field on a distance close to the antenna (typically 3 to 10 ...
Rigorous testing of the loop Yagi–Uda (quad) antenna show the following advantages over a dipole-based Yagi–Uda antenna made from dipoles: [10] Polarization It is easy to change polarization from vertical to horizontal, by changing the feed point. Multiband antenna It is easier to design a multiband quad antenna than a multiband Yagi antenna.
Patch antenna gain pattern. A directional antenna or beam antenna is an antenna which radiates or receives greater radio wave power in specific directions. Directional antennas can radiate radio waves in beams, when greater concentration of radiation in a certain direction is desired, or in receiving antennas receive radio waves from one specific direction only.
In its use as a television antenna, it was common to combine a log-periodic design for VHF with a Yagi for UHF, with both halves being roughly equal in size. This resulted in much higher gain for UHF, typically on the order of 10 to 14 dB on the Yagi side and 6.5 dB for the log-periodic. [5]
The axis of maximum radiation, passing through the center of the main lobe, is called the "beam axis" or boresight axis". In some antennas, such as split-beam antennas, there may exist more than one major lobe. The other lobes beside the main lobe, representing unwanted radiation in other directions, are called minor lobes.