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A Π-pad attenuator formed from two symmetrical L sections. Because of the symmetry, R 1 = R 3 in this case. For an attenuator, Z and Y are simple resistors and γ becomes the image parameter attenuation (that is, the attenuation when terminated with the image impedances) in nepers. A Π pad can be viewed as being two L sections back-to-back as ...
Fixed attenuators in circuits are used to lower voltage, dissipate power, and to improve impedance matching. In measuring signals, attenuator pads or adapters are used to lower the amplitude of the signal a known amount to enable measurements, or to protect the measuring device from signal levels that might damage it. Attenuators are also used ...
In telecommunications, the free-space path loss (FSPL) (also known as free-space loss, FSL) is the attenuation of radio energy between the feedpoints of two antennas that results from the combination of the receiving antenna's capture area plus the obstacle-free, line-of-sight (LoS) path through free space (usually air). [1]
To match the impedances, both cables must be connected to a matching transformer with a turns ratio of 2:1. In this example, the 300-ohm line is connected to the transformer side with more turns; the 75-ohm cable is connected to the transformer side with fewer turns. The formula for calculating the transformer turns ratio for this example is:
An asymmetrical attenuator in Pi formation with resistor values 20, 12 and 8 Ω left to right. Injecting 6 amperes into port 1 of this network produces 24 volts at port 2. The previous attenuator showing port 1 current splitting to 3 A in each branch. Injecting 6 amperes into port 2 produces 24 volts at port 1.
Attenuation constant can be defined by the amplitude ratio | A 0 A x | = e α x {\displaystyle \left|{\frac {A_{0}}{A_{x}}}\right|=e^{\alpha x}} The propagation constant per unit length is defined as the natural logarithm of the ratio of the sending end current or voltage to the receiving end current or voltage, divided by the distance x involved:
Any component of the transmission line that has an input and output will contribute to the overall mismatch loss of the system. For example, in mixers mismatch loss occurs when there is an impedance mismatch between the RF port and IF port of the mixer [dubious – discuss]. [4]
A T-pad attenuator formed from two symmetrical L sections. Because of the symmetry, R 1 = R 3 in this case. For an attenuator, Z and Y are simple resistors and γ becomes the image parameter attenuation (that is, the attenuation when terminated with the image impedances) in nepers. A T pad can be viewed as being two L sections back-to-back as ...