Antenna beamwidth is the angular distance between the points on the major lobe at the half-power points. It represents the angular coverage of the antenna’s main radiation lobe.

The T match is a method to make sure your antenna and transmission line work well together. It connects your high-impedance transmission line to your lower-impedance antenna in a special way that helps them communicate effectively.

In a Yagi antenna with a gamma match, the adjustable gamma rod connects to a variable capacitor. This setup is part of the gamma match system used for impedance matching.

Simple horizontally polarized antennas typically do not exhibit significant directivity (gain) unless they are positioned at a height of at least half a wavelength or more above the ground. At lower heights, the ground affects the radiation pattern, and the antenna becomes less directional.

Among the options listed, a Pi-L network provides the greatest harmonic suppression. This makes it suitable for applications where reducing harmonic interference is essential, such as in linear amplifiers.

Effective Radiated Power (ERP) is calculated by subtracting the losses (transmission line loss and transmatch loss) from the transmitter output power and adding the antenna gain.

A parabolic antenna is very efficient because it focuses all the received energy to a point where the pick-up antenna is located. This concentration of energy makes parabolic antennas highly effective for both transmitting and receiving

In a Yagi antenna with a gamma match, the center of the driven element connects to the coaxial line’s braid. This connection helps with the matching process.

Doppler shift becomes of consequence in communication via satellite on VHF/UHF frequencies. When communicating with fast-moving satellites, the Doppler effect causes a shift in frequency, which must be accounted for to maintain a stable connection.

The takeoff angle of the main lobe of a Yagi antenna decreases with increasing height above flat ground. This means that the main lobe becomes more elevated as the antenna is raised higher. Lower takeoff angles are desirable for long-distance communication.

Among the options listed, the loaded helical-wound antenna does not produce circular polarization. The other antennas mentioned, such as the Lindenblad antenna, axial-mode helical antenna, and crossed dipoles fed 90 degrees out of phase, are known for producing circular polarization.

A quarter-wavelength transmission line presents a very low impedance when it is open at the far end. This is because at a quarter-wavelength, the voltage at the far end is at its minimum, and the current is at its maximum, resulting in a low impedance point.

A helical-beam antenna is capable of responding simultaneously to both vertically- and horizontally-polarized signals. This dual-polarization capability makes helical antennas versatile for various signal receptions.

Greater distance can be covered with multiple-hop transmissions by decreasing the vertical radiation angle of the antenna. Lowering the vertical radiation angle allows the signal to propagate more efficiently through the ionosphere and bounce off the Earth’s surface for multiple hops, enabling long-distance communication.

The reciprocal of the square root of the dielectric constant of the material used to separate the conductors in a transmission line gives the velocity factor of the line. The velocity factor is a crucial parameter in understanding signal propagation characteristics in the transmission line.

For long-distance propagation, the vertical radiation angle of the energy from the antenna should be less than 30 degrees. Lower angles allow the signal to travel closer to the ground and maximize its reach for long-distance communication.

The velocity factor in a transmission line is primarily determined by the dielectric material used in the line. Different dielectric materials have different velocity factors, which affect the speed of signal propagation in the line.

A pi-L network provides greater harmonic suppression compared to a pi-network when matching between a vacuum tube linear amplifier and a multiband antenna. This is valuable for reducing unwanted harmonic interference.

Effective Radiated Power (ERP) is calculated by subtracting the losses (transmission line loss) from the transmitter output power and adding the antenna gain.

In a center-fed half-wave antenna, the feed point is strategically placed at the point of maximum current. This configuration allows for efficient energy transfer and radiation.

The antenna efficiency can be calculated using the formula: Efficiency = (radiation resistance / total resistance) x 100. In this case, the efficiency is (50 milliohms / 52 milliohms) x 100 ≈ 96.15%.

A pi-network is a type of impedance matching network consisting of one inductor and two capacitors (π configuration) or two inductors and one capacitor (T configuration). It is commonly used in antenna tuners and other RF circuits to match impedances.

The approximate beamwidth of a beam antenna can be determined by noting the two points where the signal strength is down 3 dB (decibels) from the maximum signal point and then computing the angular difference between these points. This method provides an estimation of the antenna’s beamwidth.

The gain of a parabolic dish antenna for amateur radio use primarily depends on the diameter of the antenna in wavelengths. This dimension is a key factor in determining the antenna’s gain, with larger diameters generally providing higher gain. Other factors, such as the material composition of the dish and the focal length, can also influence performance but are secondary to the antenna’s physical size.