An omnidirectional antenna can be practically implemented but an isotropic antenna cannot be implemented practically. An isotropic antenna resembles an ideal antenna with ideal values for all parameters.
An isotropic material has properties which are independent of the direction in which they are measured whereas in an anisotropic material the properties do depend on the direction .
It depends upon the type of antenna. For example, a Yagi antenna's gain can be increased by adding elements. A parabolic antenna's gain can be increased by increasing the diameter of the antenna. All antennas can have their gain increased by lowering the loss of the feed line. By replacing regular coaxial cable with nitrogen pressurized coax, the overall gain at the receiving end can be increased. Gain can also be increased by inserting an amplifier between the antenna and the receiver. Another method of increasing gain is to reduce the VSWR, or voltage standing wave ratio.
By inserting the upper polarizes between crossed polarizes.
antenna maybe defined astw structure associated with the transition between guided wave and free space (or) wise versa.
difference between clucth and coupling
The isotropicantenna by definition has a radiation pattern that is a perfect sphere. The omni driectional antenna is characterized by a radiation pattern resembling a doughnut.
Has to depend on the application. If the omni's are truly isotropic, then the free space loss between them is 95.66 dB at one mile separation.
An isotropic material has properties which are independent of the direction in which they are measured whereas in an anisotropic material the properties do depend on the direction .
An Omnidirectional antenna generates a beam in all directions and is defined as one "having an essentially non-directional pattern in a given plane and a directional pattern in any orthogonal plane". A Smart antenna however, often referred to as an adaptive antenna, utilises adaptive DSP based techniques and digital technology. The original analogue signals must be converted to digital form through the use of digital converters. Consequently, the nulling of a given interference and the steering of the main beam to a known direction can be achieved by changing the phases and amplitudes of the signals in individual elements of the array.
There is no difference between the two.
The transmitter or radio is the device that gives the "frequency" (for example "Ubiquiti XR7 radio") and the antenna is the device that irradiates that frequency. We have to consider that each type of antenna irradiates in a different way (for example dipole antennas that are omnidirectional or yagi antennas that are directive)
Hertz Antenna is lambda by 2 antenna & marconi antenna is lambda by 4 antenna...
An active antenna has a amplifier built in, a standard antenna does not. AKA powered antenna.
It depends upon the type of antenna. For example, a Yagi antenna's gain can be increased by adding elements. A parabolic antenna's gain can be increased by increasing the diameter of the antenna. All antennas can have their gain increased by lowering the loss of the feed line. By replacing regular coaxial cable with nitrogen pressurized coax, the overall gain at the receiving end can be increased. Gain can also be increased by inserting an amplifier between the antenna and the receiver. Another method of increasing gain is to reduce the VSWR, or voltage standing wave ratio.
about 40 db about 40 db
There are a few terms that need to be understood. [dBm,dBd,dBi and dB] For antennas, a common reference unit is the dBi, which states the gain of an antenna as referenced to an ISOTROPIC source. An Isotropic source is the perfect omnidirectional radiator, a true "Point Source", and does not exist in nature. Consider it a source which is the center of the sphere and the energy is coming equally out of it as a sphere. Now in reality nothing like that exists. It's also 2.41 dB BIGGER than the next common unit of antenna gain, the dBd, When you convert that to a real antenna. So a simple dipole antenna has a gain of 2.41dBi, and a gain of 0dBd, since we're comparing it to itself. Now lets talk about dBm, dBm is not is reference to anything else but the used as an actual gain ( say amplifiers ) , P(dBm)=10*LOG(1000*Power in milliwatts,10), an amp with an output of 30dBm puts out 1 Watt. It is not in refernce to two power level but directly correlating the gain of a device. Now when you talk about a dB it is a relative measure of two different power levels. 10log (p1/p2, 10).
If it has antenna that stick up it is a boy and if it has antenna that stick out it is a girl.