0
If you run the antenna under test in the receiving mode, then while it is rotated, you'll monitor signals received by the antenna under test. If you run the antenna under test in the transmit mode, then while you rotate it, you'll monitor signals received by a different antenna on the test range. Either way, the varying signal must be monitored at the receiving end of the link. It's a lot more convenient, and a simpler configuration, to have the signal monitor and the rotation/excitation controls for the antenna under test in the same place, in order to react appropriately to any funny things noted during the test run.
Wiki User
∙ 14y ago
Add your answer:
Earn +20 pts
What is the working principle of wireless power transmission?
The working principle behind wireless power transmission is electromagnetic induction. Let's look at it. We need a power source and a transmitting antenna, and also a receiving antenna to which we can connect the thing to be powered (the electrical load, or just the load). The power source will deliver a high power signal to the antenna. This will create an electrostatic field around the antenna that changes as the signal to it changes. This will create electromagnetic waves that will travel out from the antenna and through the air. The receiving antenna will be in the path of these waves, and the waves will pass by it and "sweep" it with their moving electromagnetic fields. This will induce a signal in the receiving antenna proportional to the energy that the antenna captures. This signal will cause current flow that will power the load. The problem with this system is that it is challenging to "direct" and "confine" the transmitted signal to optimize how much of it gets to the receiving antenna. Additionally, distance causes loss, and there will be a lot of loss over longer distances. The more the distance the signal travels, the much more the loss. But the system works to a limited degree. Links can be found below.
What is positive antibodies?
Receiving a positive blood test for antibodies associated with a particular disease.
What is the difference between an aerial and an antenna?
i think.... and i only think this, it may not be correct, an antenna transmits as well as receives, an aerial only receives there is no difference between antenna and aerial. According to British spelling it is called Aerial and according to American English antenna. So there is no difference just the English In the U.S. sometimes antenna is used for rigid structures used to transmit or receive radio signals, while aerial is used for a simple wire hung between insulators used to transmit or receive radio signals.
Device that can both transmit and receive a radio signal?
Radio receivers are designed to receive radio signals in conjunction with a receiving antenna.
Block diagram of microwave communication link?
Transmitter => Antenna =========> Antenna => Receiver Receiver <=== Antenna <========= Antenna <= Transmitter
Does a signal being transmitted from an antenna to a receiving antenna lose strength exponentially?
Yes.
What is the importance of antenna in a wireless communication system?
For wireless communication systems, the antenna is one of the most critical components. A good design of the antenna can relax system requirements and improve overall system performance. An antenna is the system component that is designed to radiate or receive electromagnetic waves. In other words, the antenna is the electromagnetic transducer which is used to convert, in the transmitting mode, guided waves within a transmission line to radiated free-space waves or to convert, in the receiving mode, free-space waves to guided waves.
Is the receiving antenna radiate radio wave during reception?
A receiving antenna does "re-radiate" some of the power it receives, but not all. Some of the power it receives proceeds into the receiver ... which is the only way we detect the signal being received by the antenna.
What is longwire?
It's a type of radio signal receiving antenna
What is the difference between transmitting and receiving antenna?
There is no difference between the two.
How you can inceares efficiency of antenna?
Height, direction, antenna type and down lead are major factors in receiving a good TV signal to the TV set.
Show that doubling the transmission frequency or doubling the distance between transmitting antenna and receiving antenna attenuates the power received by 6 dB?
english
How wireless computers understands radio waves?
As computers have receiving antenna with resonating sensors.
How does the frequency of an electromagnetic wave compare with that of the electrons it sets into oscillation in a receiving antenna?
The frequency of an electromagnetic wave must be very high to release electrons. The electrons that it releases are set into oscillation in a receiving antenna must by definition have a lesser frequency.
How do you increase the strength to the receiving antenna?
I think the question needs to know how to increase signal strength from Receiving Antenna.1. Use Better and bigger Ground. This will not only increase signal but will also increase S/N ratio.2. Generally increasing the size of antenna helps.3. Use elements that can increase the effective area of the antenna.4. Ensure that the antenna is well matched to the feeder feeding the RF signal.
How is the radiation pattern of a parabolic reflector antenna plotted?
The paraolic antenna has a high degree of "directivity" compared to many other antennas. That gives these puppies big gain. But they need to be pointed in the "right" direction to work well. This antenna design is used in many radar (and other microwave) applications, as well as in satellite communication. And is has a home with radio astronomers, too, but they're usually listening instead of transmitting. It has a parabolic reflector, and some kind of support for the feedhorn, sub-reflector or whatever is at the focus. We're talking about a transmission antenna here, so there will be some kind of feed assembly to put the signal onto the parabolic reflector to "send out" or transmit that signal. How do we test it? It's so simple that you're not gonna believe it. The reflector can be modified a bit to "broaden" the primary lobe of the radiated signal either horizontally or vertically. But let's work with a simple parabolic reflector. Imagine a parabolic antenna that is fixed so it's stationary. Let's look at which way the signal goes. There are two variables to assess when plotting the radiated pattern, and they are usually referenced to the "direction" or "directivity" of the antenna, or the direction of what might be termed the primary lobe or beam of the radiation. Put another way, there is one direction that is the "center of the beam" for this antenna, and once we establish this line, we reference to it. Something is either left or right of the line by "x" number of degrees, or something is above or below the line by "y" degrees. You gonna put this up on a pole and walk around measuring radiated power at different points left or right of, or above or below the beam? Remember I said this was ease? Put the antenna on a stand and make it point horizontally. Make that stand like a heavy duty lazy susan so the whole thing rotates. Hook up a signal generator to it, and put in the desired operating frequency. (The signal generator won't be generating high power, and that's okay. A milliwatt isn't even necessary for the test.) We're now ready to transmit, and that's our test antenna setup. Step off a hundred meters (or whatever) and set up a receiving antenna (pointed at the antenna under test and at the same level). Hook up a receiver to the receiving antenna so that signal strength can be measured. Turn on your equipment and rotate the turntable slowly. As the turntable rotates, it causes the antenna being tested to "sweep" the horizon with its little output signal. As it moves around, the receiver will be getting more and more and more signal, or less and less and less signal, depending on whether the test antenns is sweeping toward or away from the receiver. With a computer hooked up to the receiver (via a handy IEEE bus) and doing some recording, a relative signal strength can be plotted. Presto! You've got a 360o plot of the relative output signal strength. All you have to do is raise you receiving antenna a touch, and then point it down a tiny bit so it's aimed directly at the test antenna. Then turn the test antenna and record for another 360o view at a bit high of beam center. Keep moving up the receiving antenna in steps, realigning it, and testing a circle. Do this for a bunch of vertical levels above beam center. Then come back and do it again for a bunch of levels below beam center. You're done! The trick is to set up the test antenna on a turntable and point it flat out and level with the horizon, and then to begin with a receiving antenna level with and pointed directly at the test antenna. The turntable does most of the work, and it makes it easy. The work is in raising or lowering the receiving antenna in calculated steps and realigning it at each step to point it directly at the test antenna. By the time the test crew get finished, the computer can plot a nice 3D chart (in the form of a thick cylinder with the test antenna at the center that will demonstrate the performance of that test antenna. Piece of cake. The paraolic antenna has a high degree of "direcitivity" compared to many other antennas. That gives these puppies big gain. This antenna design is used in many radar and in satellite communication applications, as well as having a home with radio astronomers. It has a parabolic reflector, and some kind of support for the feedhorn, sub-reflector or whatever is at the focus. We're talking about a transmission antenna here, there will be some kind of feed assembly to put the signal onto the parabolic reflector to "send out" or transmit the signal. How do we test it? It's so simple that you're not gonna believe it. The reflector can be modified a bit to "broaden" the primary lobe of the radiated signal either horizontally or vertically. But let's work with a simple parabolic reflector. Imagine a parabolic antenna that is fixed so it's stationary. Let's look at which way the signal goes. There are two variables to assess when plotting the radiated pattern, and they are usually referenced to the "direction" or "directivity" of the antenna, or the direction of what might be termed the primary lobe of the radiation. Put another way, there is one direction that is the "center of the beam" for this antenna, and once we establish this line, we reference to it. Something is either left or right of the line by "x" number of degrees, or something is above or below the line by "y" degrees. You gonna put this up on a pole and walk around measuring radiated power at different points left or right of, or above or below the beam? Remember I said this was ease? Put the antenna on a stand and make it point horizontally. Make that stand like a heavy duty lazy susan so the whole thing rotates. Hook up a signal generator to it, and put in the desired operating frequency. (The signal generator won't be generating high power, and that's okay. A milliwatt isn't even necessary for the test.) We're now ready to transmit, and that's our test antenna setup. Step off a hundred meters (or whatever) and set up a receiving antenna (pointed at the antenna under test and at the same level). Hook up a receiver to the receiving antenna so that signal strength can be measured. Turn on your equipment and rotate the turntable slowly. As the turntable rotates, it causes the antenna being tested to "sweep" the horizon with its little output signal. As it moves around, the receiver will be getting more and more and more signal, or less and less and less signal, depending on whether the test antenns is sweeping toward or away from the receiver. With a computer hooked up to the receiver (via a handy IEEE bus) and doing some recording, a relative signal strength can be plotted. Presto! You've got a 360o plot of the relative output signal strength. All you have to do is raise you receiving antenna a touch, and then point it down a tiny bit so it's aimed directly at the test antenna. Then turn the test antenna and record for another 360o view at a bit high of beam center. Keep moving up the receiving antenna in steps, realigning it, and testing a circle. Do this for a bunch of vertical levels above beam center. Then come back and do it again for a bunch of levels below beam center. You're done! The trick is to set up the test antenna on a turntable and point it flat out and level with the horizon, and then to begin with a receiving antenna level with and pointed directly at the test antenna. The turntable does most of the work, and it makes it easy. The work is in raising or lowering the receiving antenna in calculated steps and realigning it at each step to point it directly at the test antenna. By the time the test crew get finished, the computer can plot a nice 3D chart (in the form of a thick cylinder with the test antenna at the center that will demonstrate the performance of that test antenna. The output pattern should look like a long, skinny teardrop. Piece of cake.
How do you install a universal antenna?
Remove the old antenna. Attach the universal antenna to the radio and replace the radio after finishing the task. Install the new antenna. Test to ensure the wiring works.
