Discover the expert in you.
Discover the expert in you.
Co-phasing, also known as "stacking," is a technique for connecting a pair of mobile CB (Citizens' Band) antennas to a single transceiver. Typically, the antennas are physically mounted to the side mirror brackets of a large truck. Because each antenna matches the impedance of the 50-ohm coax cable feed from the radio, the installer must buy or build a co-phase harness to transform the resultant 25-ohm impedance to 50 ohms. This entails adding an electrical one-quarter-wavelength section of 75-ohm coax to each antenna.
The angular range of an antenna's received or transmitted signal is referred to as its beamwidth. This is based on a measurement of the antenna and the frequency of the signal. The calculation of this distance requires you to determine the variables that you need to use. Once the variables are found, you then need to perform a simple equation to obtain the beamwidth of an antenna.
The study of electromagnetic radiation covers a large range of wavelengths. It spans from nm or Angstroms for visible light to meters for radio waves. Each region of the spectrum has its own terminology for expressing the wavelength of the radiation. A rather unique unit of measure occurs in the infrared and near infrared region of the spectrum. The wavelengths are measured in wavenumbers (cm^-1). In order to work across a wider range of the spectrum, it is helpful to convert from this odd reference system to a system that is more standard for discussing wavelength.
Frequency and wavelength are two values used to describe the shape and behavior of waves, such as light or sound waves. Frequency is defined as the time it takes a wave to complete one full cycle. The wavelength is the distance between any two crests or troughs of a wave. These two values are directly related; if the frequency and speed of a wave are known, solving a simple equation will give the wavelength.
The term "redshift" refers to a state in which light waves emanating from astronomical bodies moving away from Earth, especially galaxies, lengthen into the red end of the light spectrum. This shift, which is also a form of the Doppler Effect, indicates objects moving away from one another. Consequently, red-shifting galaxies present evidence of an expanding universe.
The Rydberg equation is a simple formula invented in the late 19th century to predict atomic spectra for hydrogen. It can also be used to predict the wavelength of light absorbed by electrons undergoing transitions in some other atoms as well, although typically it's used for hydrogen, for which it is most applicable. Basically, it takes the principal quantum number of the electron shells an electron occupies, before and after a transition, as inputs, and uses these to calculate the wavelength of light emitted by the electron when it fell to the lower energy state.
Photons travel in electromagnetic beams, oscillating through a plane at right angles to the wave's direction. The wavelength is the distance between peaks of the wave, and this value is related to the number of photons that the beam carries. A wave with a lower wavelength carries more energy, and this energy increase corresponds with a greater number of photons moving each second. The ratio that relates the energy in each photon to the wavelength is Plank's constant, which is approximately 6.63 x 10^-34 joule-seconds.
Wavelengths are defines as the speed of the wave divided by the frequency of the wave. Commonly measured wavelengths in physics include sound and light. Calculating the wavelength of sounds or lights, then, requires that you know the speed of light or sound and the frequency of the particular instance of sound or light you are trying to measure.
Energy takes many forms including light, sound and heat. Different colors of light are given by photons of various wavelengths. The relationship between energy and wavelength are inversely proportional, meaning that as the wavelength increases the associated energy decreases. A calculation for energy as it relates to wavelength includes the speed of light and Planck's constant. The speed of light is 2.99x10^8 meters per second and Planck's constant is 6.626x10^-34joule second. The calculated energy will be in joules. Units should match before performing the calculation to ensure an accurate result.
A "redshift" is the displacement of an astronomical object toward the red end of the color spectrum, meaning that its light wave is lengthening. This change in length indicates that the source of waves and the observer are both in rapid motion in relation to each other. In astronomical terms, this indicates that objects are pulling away from the observing point of view. The length of the redshift is directly proportional to the distance increased, therefore calculating the span of red light indicates how far the distance between those two object increased during that time.
In 1923, Louis de Broglie proposed that because light can behave as particles even though it possesses no mass, objects with mass can also exhibit wave-like properties. De Broglie merged equations for the energy of a particle with mass and the energy of a light particle with no mass and arrived at the equation lamba = h / mv, where lambda represents the wavelength in meters, h is Planck's constant (6.626 x 10^-34 joule seconds), m represents the object's mass in kilograms and v represents its velocity in meters per second. Thus, any object with mass that exhibits motion will…
Waves are periodic functions having properties such as a wavelength and a frequency. The wavelength is the distance from one wave crest to the next crest. Frequency is the number of the wave periods per second that is measured in Hertz (Hz). The following equation describes the relationship between the frequency and the wavelength: wavelength = speed of light / frequency. The speed of light is the fundamental physical constant. Use a calculator to calculate the wavelength for the wave with the frequency 3 GHz.
In their lowest-energy configuration, the electrons in a hydrogen molecule occupy an energy level of n = 1, where n refers to the electrons' principal quantum number. When a hydrogen molecule absorbs energy, however, either in the form of heat or light, the electrons transfer to higher energy levels. The electrons cannot sustain this "excited" state, however, and eventually relax back to a lower level. Under the law of conservation of energy, the extra energy the electrons absorbed cannot simply disappear when the electrons relax to a lower energy level. The energy differences between the levels determines the energy of…
Solar cells turn electromagnetic radiation into electrical energy. When photons of light are absorbed, they excite the electrons so they escape their normal positions to form part of an electric current. Changing the wavelength of light affects the conversion efficiency.
The study of light has always fascinated scientists because this natural phenomena can behave in two different manners. While wavelengths and the spectrum of light have been known and studied for several centuries, the behavior of light as a particle was not discovered until the twentieth century. The wave number (or wavenumber) is a numerical value dependent on the wavelength of the electromagnetic field or light source. As a result to calculate the wave number, one must first know the wavelength.
Redshift is a term used in astronomy to describe the displacement of light waves toward the red end of the spectrum. Waves that shift in this manner are considered to be lengthening, which is one of the evidences used to judge that the distance between two objects is increasing. American astronomer Edwin Hubble first reported in 1929 that distant galaxies were receding from Earth's position in the Milky Way galaxy, and that their redshifts were increasing proportionally with their increasing distance. This gave rise to Hubble's law, which is used to measure the recessional velocity of objects from each other…
The wavelength is a measure between crests of adjacent waves or troughs of adjacent waves. While wavelength may sometimes be directly measured, often it is simpler to calculate the wavelength based on the frequency and speed of the wave. The speed of the wave is equal to the frequency multiplied by the wavelength (wave speed = frequency x wavelength), and this equation may be rewritten to allow wave speed and frequency to solve for wavelength. This is especially useful when measuring the wavelengths of electromagnetic waves since these waves travel at the speed of light which is a known value.…
Angular resolution, also known as the Rayleigh criterion and spatial resolution, is the minimum angular distance between two distant objects that an instrument can discern resolvable detail. As an example, if a person holds two pens 10cm apart and stands 2m from you, you can discern there are two pencils. As the other person moves away, the pencils appear to move closer together or the angular separation decreases. The calculation of this angle is very important in optics. This angle represents the resolve power and precision of optical instruments such as your eye, a camera and even a microscope.
The simplest antennas are straight, long pieces of wire. A dipole antenna takes the concept a little further, using two pieces of wire held together in the middle by an insulator. You can calculate the range of wavelengths for a dipole antenna with a simple formula. The antenna is sensitive to a base frequency and also will pick up odd-numbered multiples of this frequency.
In the field of physics known as quantum mechanics, the Bohr model of the hydrogen atom is a seminal theory for how electrons behave when exposed to energy. According to this model, the space surrounding the nucleus of the atom is arranged into a set of discrete zones called "orbitals." In order to occupy a particular orbital, the electron surrounding the nucleus must carry a certain minimum amount of energy. In order to occupy a lower-energy orbital, the electron releases a portion of its energy as a photon of light. The wavelength of this photon is determined directly by the…
Electrons are elementary particles that carry a negative charge. Electrons are employed in several important experimental techniques, such as the electron diffraction or the electron microscopy. The electron wavelength serves as a crucial parameter in the both techniques. In physics, the de Broglie's principle states that electrons, while being particles, behave also like waves. The corresponding equation defines the wavelength via the electron momentum that can be calculated using the energy commonly expressed in electron volt (eV) units.
Beamwidth is a representation of the angular range of an antenna's transmitted or received signal. The theoretical beamwidth depends on the geometry of the antenna and the frequency of the signal. Actual beamwidth can be calculated from measurements of the peak power and the angles, to the points where the signal power is half its peak value. These are known as the 3 dB points. The received voltage level drops to a value of half the square root of two (.707) or 3 deciBels below the peak.
A wavenumber is a characteristic of the electromagnetic radiation and obtained by inversing a wavelength. Wavenumbers are commonly used in spectroscopy and traditional expressed in inverse centimeters (cm^-1). Wavenumbers can be calculated not only from wavelength but also from the light energy or frequency of radiation.
Waves are described using periodic sine functions, and a wavelength indicates a length of a function period, i.e., is the distance between any two points with the same phase. "Light" typically refers to electromagnetic radiation with wavelengths from 400 to 700 nm that are visible by a human eye. The wavelength of light can be calculated either from the light energy or frequency using the speed of light and Planck constants. Energy of light is typically expressed in electron volt (eV) units while the frequency is measured in Hertz (1 Hz equals 1/sec).
