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Up to which frequency does the gain of an antenna increase as the frequency increases?
In general, an antenna is "cut" or "built" for one frequency, or for a band of frequencies centering on one particular frequency. This antenna will respond to all frequencies, but will only exhibit "maximum" gain at one frequency. Frequencies higher or lower will not be received quite as well, and the farther from the "tuned" or "center" frequency the signal is, the less gain the antenna will provide on that frequency. As we work with an omnidirectional antenna, we can "tinker" with it a bit in an attempt to get it to work with a broader range of frequencies, but as we broaden the usable spectrum over which it will work, we will see less gain on the "center" frequency. If you're getting the idea that tuning an antenna involves trade-offs, you're getting the right picture. No improvements are possible without "cost" in another part of the operating spectrum. If we move to a directional TV antenna like, say, one of those antennas (not the dish) that still can be seen on some rooftops, we see what is basically a modified log periodic antenna. This antenna will generally be "pointed" or "aimed" in the general direction of the transmission antenna of the station(s) for which reception is desired. Stations with broadcast antennas to the side or the rear of this antenna won't be "seen" as the antenna is highly directional. Having said all that to get you up to speed on some fundamental concepts of the antenna, as we move up the frequency spectrum (starting "low"), the gain of the antenna will increase until we reach the "center" or the "tuned" frequency for that antenna. After that, increasing the frequency will result in signals with increasingly lower gain.
What else can I help you with?
Why gain increases in low frequency region in BJT?
Because Beta (current gain) in a transistor is inversely proportional to frequency. Hence it increases as frequency decreases. Also the ac voltage gain is directly proportional to Beta.
What is the effect on voltage gain in a common emitter amplifier when the decoupling capacitor is removed?
The emitter bypass capacitor, in a typical common emitter configuration, increases gain as a function of frequency, making a high pass filter. Removing the capacitor will remove the gain component due to frequency, and the amplifier will degrade to its DC characteristics.
What is the function of emitter bypass capacitor in common emitter amplifier?
The emitter bypass capacitor in a common emitter amplifier will have less resistance as the frequency increases. Since gain in this configuration is collector resistance divided by emitter resistance (within limits of hFe), the gain will thus increase for higher frequencies, making this into a high pass filter.
If antenna is passive than how can it add gain?
Antennas provide so called passive gain, which means it comes from particular shape of the antennaThe gain of an antenna is a passive phenomenon - power is not added by the antenna, but simply redistributed to provide more radiated power in a certain direction than would be transmitted by an isotropic antenna. If an antenna has a gain greater than one in some directions, it must have a gain less than one in other directions, since energy is conserved by the antenna.SOURCE: wikipedia.com
What is antenna tilt?
Antenna gain of base station for a specific user depends on antenna pattern, antenna orientation (azimuth and tilt) and user's coordinates with respect to base station.
When antenna diameter is doubled what will happen to antenna gain?
increases by 6 dB
The of an antenna depends upon the frequency of the RF signal and the gain?
The size of an antenna depends upon the frequecny of the RF signal and the gain.
Why would there be a gain when you add the emitter capacitor to a circuit board?
A capacitor has lower resistance (impedance) as frequency increases. Adding an emitter capacitor effectively lowers the emitter resistance as frequency increases. Since gain in a typical common emitter amplifier is collector resitance divided by emitter resistance, this decrease in emitter resistance will increase gain as frequency increases.
Why gain increases in low frequency region in BJT?
Because Beta (current gain) in a transistor is inversely proportional to frequency. Hence it increases as frequency decreases. Also the ac voltage gain is directly proportional to Beta.
What are the advantages of high frequency in transmission?
Some advantages are:As the frequency increases, the so does the data transfer speeds.The gain and directivity of the transmission antenna will increase for the the same size.Although signals experience more attenuation at high frequency, this could be advantageous for covert purposes.Ultimately, each band has certain limitations, depending on what the FCC has them dedicated for. So higher frequency could be great, but could be power limited.
If the diameter of an objective mirror is doubled its light-gathering power becomes?
Just like any antenna used to collect electromagnetic energy at any other frequency, the 'gain' is proportional to the antenna's area. Since the area varies as the square of the collector's diameter, doubling the diameter increases the gain by a factor of 22 = 4. The corresponding increase in gain is 6 dB.
The gain of an operational amplifier will be maximum?
A: the gain will be maximum at the open loop configuration and decrease as frequency increases
What is the effect on voltage gain in a common emitter amplifier when the decoupling capacitor is removed?
The emitter bypass capacitor, in a typical common emitter configuration, increases gain as a function of frequency, making a high pass filter. Removing the capacitor will remove the gain component due to frequency, and the amplifier will degrade to its DC characteristics.
What factors determine antenna gain?
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.
What is the effect of low frequency on the voltage?
The frequency would decrease the gain and increase the output voltage
What are four different effects of feedback on the function of an amplifier?
1. Negative feedback can increase linearity at the expense of losing gain. 2. & 3. Positive feedback can result in large increases in gain until the increases becomes so large that oscillation occurs. 4. Positive or negative feedback at one frequency can result in enhanced or decreased response to that frequency.
What is gain roll off?
A: As frequency increases all amplifier exhibits losses due to internal capacity or internal devices frequency limit. At the hi end of the frequency the amplifiers begins to loose gain gradually as a function of higher frequency that is what roll off is.
