noise temperature उदाहरण वाक्य

उदाहरण वाक्य

1. For example, a satellite antenna may not receive noise contribution from the earth in its main lobe, but sidelobes will contribute a portion of the 290K earth noise to its overall noise temperature.
2. For this reason, the related figure of " effective noise temperature " is therefore often used instead of the noise figure for characterizing satellite-communication receivers and low-noise amplifiers.
3. This is likewise true for a receiving antenna at very high ( especially microwave ) frequencies, where the point is to receive a signal which is strong compared to the receiver's noise temperature.
4. The noise factor is defined as the ratio of the output noise power of a device to the portion thereof attributable to thermal noise in the input termination at standard noise temperature " T " 0 ( usually 290 K ).
5. The noise temperature of an amplifier refers to the noise that would be added at the amplifier's " input " ( relative to the input impedance of the amplifier ) in order to account for the added noise observed following amplification.
6. In the usual case where the gains of the amplifier's stages are much greater than one, then it can be seen that the noise temperatures of the earlier stages have a much greater influence on the resulting noise temperature than those later in the chain.
7. In the usual case where the gains of the amplifier's stages are much greater than one, then it can be seen that the noise temperatures of the earlier stages have a much greater influence on the resulting noise temperature than those later in the chain.
8. Hence, an isotropic antenna would have a noise temperature that is the average of all temperatures around the antenna; for a perfectly directional antenna ( with a pencil beam ), the antenna temperature will only depend on the temperature in which the antenna is " looking ".
9. If a signal is present, then the decrease in signal to noise ratio incurred using the receiver system with a noise temperature of T _ { sys } is proportional to 1 / T _ { ant }-1 / ( T _ { ant } + T _ { sys } ).
10. Dicke is also credited with the invention of a kind of radio receiver, called a " Dicke Radiometric Receiver " or simply " Dicke Radiometer ", developed by Dicke during WWII . His radiometer was characterized by a noise temperature calibration technique using a switchable resistor, known as " Dicke Resistor ".