What are the applications of log-periodic antenna?

What are the applications of log-periodic antenna?

Log periodic antenna applications

• HF communications: Log periodic antenna arrays are often used for diplomatic traffic on the HF bands.
• UHF Terrestrial TV: The log periodic antenna is sometimes used for UHF terrestrial television reception.
• EMC measurements: EMC is a key issue for all electronic products.

Why is log-periodic antenna called so?

Log periodic antenna is so named because its characteristics, could be gain or impedance, shows a periodic variation with log of the input frequency. The principle of operation may be explained by considering a log periodic dipole array. It contains a large number of elements.

What are the three regions of log-periodic antenna?

There are several type of log-periodic antennas such as the planar, trapezoidal, zig-zag, V-type, slot and the dipole. The mostly used one is log-periodic dipole array, in short, LPDA. The diagram of log-periodic array is given above.

How do log-periodic antennas work?

Basic concept. The LPDA normally consists of a series of half wave dipole “elements” each consisting of a pair of metal rods, positioned along a support boom lying along the antenna axis. The elements are spaced at intervals following a logarithmic function of the frequency, known as d or sigma.

What is advantage of log-periodic antenna?

The construction and operation of a log-periodic antenna is similar to that of a Yagi-Uda antenna. The main advantage of this antenna is that it exhibits constant characteristics over a desired frequency range of operation. It has the same radiation resistance and therefore the same SWR.

Which of the following describes a log-periodic antenna?

A log periodic antenna is described as one in which the length and spacing of the elements increases logarithmically from one end of the boom to the other. The advantage of this type of antenna arrangement is that it allows operation over a wide range of frequencies, rather than one static frequency band.

Is Yagi-Uda a log-periodic?

They can be thought of as two or three element Yagi antennas connected together, each tuned to a different frequency. This gives Log-periodic antennas the ability to work across a wide range of frequencies, whereas Yagi-Uda antennas are optimized for one particular frequency range.

Which of the following is an advantage of a log-periodic antenna?

Which of the following is an advantage of a log periodic antenna? An advantage of a log periodic antenna is wide bandwidth. In this type of multi-element directional antenna, the lengths of the elements and the spacing among them are both arranged in a log-periodic manner.

What are Yagi-Uda and log-periodic antenna?

Both Log-Periodic Antennas and Yagi antennas are high gain directional antennas. The main difference between these antennas is that Log-Periodic Antennas support wider frequency bandwidths and are physically much larger than Yagi antennas. Conceptually, Log-Periodic Antennas are similar to Yagi Antennas.

Which is better Yagi or LPDA?

A Yagi antenna is designed to operate in a very narrow frequency range with higher gain. It’s a narrow-bandwidth antenna. An LPDA antenna is designed to operate in a wide frequency range. with lower gain.

What is the polarization of a log-periodic antenna?

Log-periodic dipole antennas (LPDA) are mainly used for the range above 300 MHz and biconical antennas for the range less than 300 MHz. These two antennas have linear polarization.

What is a log periodic TV aerial?

Log Periodic Aerials differ from traditional Yagi-style aerials by offering a flat signal increase along the whole of the frequency range. It also rejects a lot of the signals that can cause interference. This gives a much better balanced signal across all channels.

Are log periodic aerials any good?

Apart from the aforementioned points the Log Periodic is one of the best antennas, particularly for digital, in fact the broadcast authorities use them where ever possible (for both receiving and transmitting).

How does a Vivaldi antenna work?

Vivaldi antennas can be made for linear polarized waves or – using two devices arranged in orthogonal direction – for transmitting / receiving both polarization orientations. If fed with 90-degree phase-shifted signals, orthogonal devices can transmit/receive circular-oriented electromagnetic waves.