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Checking the SWR is a standard procedure in a radio station. Although the same information could be obtained by measuring the load's impedance with an impedance analyzer (or "impedance bridge"), the SWR meter is simpler and more robust for this purpose. By measuring the magnitude of the impedance mismatch at the transmitter output it reveals ...
To test for a match, the reference impedance of the bridge is set to the expected load impedance (for example, 50 Ohms), and the transmission line connected as the unknown impedance. RF power is applied to the circuit. The voltage at the line input represents the vector sum of the forward wave, and the wave reflected from the load.
Antenna measurement techniques refers to the testing of antennas in order to ensure that the antenna meets specifications or simply to characterize it. Typical antenna parameters are gain, bandwidth, radiation pattern, beamwidth, polarization, impedance; These are imperative communicative means.
Then it may be said that the coil has lengthened the antenna to achieve an electrical length of 2.5 meters. However, the resulting resistive impedance achieved will be quite a bit lower than that of a true 1 / 4 wave (resonant) monopole, often requiring further impedance matching (a transformer) to the desired transmission line. For ...
The impedance, Z, of the DUT can be calculated from the reflection coefficient by, = + where Z 0 is the characteristic impedance of the line. An alternative method is to plot the VSWR and distance to the node (in wavelengths) on a Smith chart. These quantities are directly measured by the slotted line.
Impedance discontinuities cause attenuation, attenuation distortion, standing waves, ringing and other effects because a portion of a transmitted signal will be reflected back to the transmitting device rather than continuing to the receiver, much like an echo. This effect is compounded if multiple discontinuities cause additional portions of ...
The input impedance is slowly varying over this wide frequency range, allowing low voltage standing wave ratio (VSWR) over the bandwidth. [1] The gain of horn antennas ranges up to 25 dBi, with 10–20 dBi being typical. [1]
Load-pull is the colloquial term applied to the process of systematically varying the impedance presented to a device under test (DUT), most often a transistor, to assess its performance and the associated conditions to deliver that performance in a network. [1]