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The mixer circuit can be used not only to shift the frequency of an input signal as in a receiver, but also as a product detector, modulator, phase detector or frequency multiplier. [6] For example, a communications receiver might contain two mixer stages for conversion of the input signal to an intermediate frequency and another mixer employed ...
It is possible to generate an AM signal by taking the output from the balanced modulator and reinserting the carrier. [3] In the Armstrong method, the audio signal and the radio frequency carrier signal are applied to the balanced modulator to generate a double sideband suppressed carrier signal. The phase of this output signal is then shifted ...
A balanced circuit will normally show a symmetry of its components about a horizontal line midway between the two conductors (example in figure 3). This is different from what is normally meant by a symmetrical circuit, which is a circuit showing symmetry of its components about a vertical line at its midpoint. An example of a symmetrical ...
The equations simplify if one chooses R 2 = R x and C 2 = C x; the result is R 4 = 2R 3. In practice, the values of R and C will never be exactly equal, but the equations above show that for fixed values in the 2 and x arms, the bridge will balance at some ω and some ratio of R 4 / R 3 .
Root locus plot of Wien bridge oscillator pole positions for R 1 = R 2 = 1 and C 1 = C 2 =1 versus K = (R b + R f)/R b. The numerical values of K are shown in a purple font. The trajectory of the poles for K=3 is perpendicular to the imaginary (β) axis. For K >> 5, one pole approaches the origin and the other approaches K. [34]
DSB-SC is basically an amplitude modulation wave without the carrier, therefore reducing power waste, giving it a 50% efficiency. This is an increase compared to normal AM transmission (DSB) that has a maximum efficiency of 33.333%, since 2/3 of the power is in the carrier which conveys no useful information and both sidebands containing identical copies of the same information.
As a mixer, its balanced operation cancels out many unwanted mixing products, resulting in a "cleaner" output. It is a generalized case of an early circuit first used by Howard Jones in 1963, [ 2 ] invented independently and greatly augmented by Barrie Gilbert in 1967. [ 3 ]
No loss occurs when the signals at ports 2 and 3 are in phase and have equal magnitude. In case of noise input to ports 2 and 3, the noise level at port 1 does not increase, half of the noise power is dissipated in the resistor. By cascading, the input power might be divided to any -number of outputs.