Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [amplitude]

46 questions
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What does "shift keying" mean in the context of digital modulation?

English is not my native language and I do not understand why the words "shift keying" were used to describe some types of digital modulation. What does "keying" mean in the context of signals and modulation? I know what a key is: something that…
yoyo_fun
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Why is the signal amplitude low on the oscilloscope even though the impedance is matched?

I have a photodetector with differential outputs that are each 50-ohm terminated. When I connect one output to the oscilloscope to look at the signal, I see a higher signal amplitude with higher channel impedance on the oscilloscope. According to my…
Mohamed Tarek
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Peak to Peak vs. Amplitude

For a sine wave, Amplitude is the fluctuation or displacement of the wave from its mean value. Peak-to-peak (pk-pk) is the difference between the maximum positive and the maximum negative amplitudes of the wave. Then why oscilloscopes display…
Yasindu
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The output amplitude of the C class amplifier I designed has a larger amplitude than the voltage source. How did this happen?

I designed a class C amplifier. I used a signal generator for the input signal. For the resonance circuit, I used a 3.3uH coil and a 480pF capacitor. The transistor is BC547-C. The resonance frequency for these values is 3.99 MHz. Due to the…
OzGtZ t
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Is there a single word term for doubled amplitude of square wave?

The IEC60050 (103-07-02) tells that the amplitude is "maximum value of a scalar sinusoidal quantity". So the peak-to-peak voltage is a doubled amplitude. Is there a single word term for a square wave (or a CMOS single-ended signal) which be…
Arseniy
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Amplitude vs Magnitude

Consider the relation between the output and input voltages: $$V_o=\frac{V_i}{2}(j-1)$$ where j is an imaginary number, and $$V_i=5sin(1000t)$$ Now, to find the amplitude of \$ V_o \$, should we look at the real part, i.e.,…
Dom Tesilbirth Shira
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Unit of ultrasound A-scans

I have a basic question concerning ultrasound A-scans. Such an A-scan might typically look as follows (source: https://img.medscapestatic.com/pi/meds/ckb/18/7418tn.jpg): I understand that the x-axis is the time axis but I'm unsure about the y-axis.…
Hagbard
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In this Amplitude Modulation circuit, what is the purpose of the diode load (L2)?

In this circuit i know that the diode mixes the signal. I know that after the diode it is a half-wave. I know that the capacitor reproduces the lost signal. I have a feeling L2 is maybe plays a part in this signal regeneration?
jake
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Testing an IC : IO PAD experiences 2nd-order ramping effect

The IO is a regular PMOS-PULL-up and NMOS-PULL-dn IO with series resistors on pull-up and pull-dn branches. The IO is input an clock signal around 50MHz and it experiences an approximately 2nd-order ramping up to 1.8V and then suddenly being pulled…
JohnLai
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Amplitude detection

Why is second analog multiplier(marked with red color) used to detect the amplitude of the input signal in this circuit instead of diode? The point of this circuit is to maintain the output level of the first multiplier constant all the time.
Sundark12
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How to make a small amplifier, able to amplify a signal 2 × the input

I have a small device expecting a signal in the 8MHz range of 2V peak-to-peak. The output of my signal generator (or rather the device that outputs the modulated signal) is only at 1V peak to peak. My idea is to construct a (very) simple amplifier…
polemon
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Is the amplitude of a sine wave increasing or decreasing in this phase?

I'm new to electrical signal, sorry if my question sounds dumb. Below is a picture from my text book: It says a sine wave with a phase of 0° starts at time 0 with a zero amplitude. The amplitude is increasing. I am little bit confused here,…
secondimage
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Amplitude influence in the output signal in inverting op-amp

I testing an inverting op amp circuit in LTspice. First I observed the graphic for the gain, and calculted the bandwidth of the circuit that is 11995Hz. Then I did a simulation at that frequency, and I was very intrigued with the result. I thought…
Catarina Branco
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Relationship between harmonic's amplitude and square wave's Tr and Pw

I started reading this TI guide on high speed layout guidelines and had some question on the theory of clock signals (pages 2 and 3). From the image below it's clear that the amplitude of the first odd harmonic (3) is inversely proportional to the…
Geo
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Understanding function generator output when units are in dBm

I am using a function generator with output in units of dBm. It has an output impedance of 50 ohms. I am measuring this output on an oscilloscope, and am failing to understand the waveform's amplitude. With the scope input impedance at 50 ohms, a 0…
teddyv
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