Questions tagged [mixer]
A mixer or frequency mixer is a nonlinear electrical circuit that creates new frequencies from two signals applied to it.
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Resistor choice for passively mixing line level and speaker level
There are a lot of great resources here for people who want to mix together multiple outputs of the same or similar load impedance. However, in my case, I want to mix a mono, amplified, ground-...
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Why does this Gilbert cell configuration not have good local oscillator suppression?
I'm doing some simulations in ADS of a Gilbert mixer based on BJTs:
If I connect the base of transistor X6 directly to GND for the AC signal like in the picture above, the mixer has a very strange LO ...
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Schematic review for ultrasonic heterodyne mixer
I'm building a heterodyne ultrasonic bat detector with a mems mic (Knowles SPU0410LR5H-QB) and the SA612 mixer. I have built it in a breadboard and it works, still with some hum and noise but I have ...
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LM386 Amplifier Mix Dual Audio Signals
I am trying to build an audio amplifier which will get input from an electret microphone and music signals from mobile using aux cable. I found a schematic diagram in the Circuit Digest website which ...
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Radar received RF signal phase-shifted by 90 to obtain I/Q signals
I am trying to get idea how marine radar works before start any repairing process. And this part confused me, most articles that i saw explain that in mixing stage we obtain I/Q signals using LO ...
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Passively mixing two (or perhaps more) speaker-level audio signals, without additional downstream amplification
I have several voice-radios with amplified mono outputs. The radios are designed to connect directly to a 4Ω speaker. I would like to connect two (or more) of them to the same speaker.
The radio ...
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Audio Mixer Circuit with Individual Volume
I'm trying to make an audio mixer circuit based on the amplifier circuit published by Scott Campbell.
I have no knowledge of opamps so I'm taking it mostly as-is but the input signal I am going to ...
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Bats ultrasounds detector with LM324
I have some questions about this small project, a device to detect bat ultrasounds and reproduce in a speaker. It's based in a post of the Element14 community, Episode 578. I have adapted it and I'm ...
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Do we require matching circuit and stability in Gilbert cell active mixer design? If yes then what is the procedure?
I'm trying to simulate a Gilbert cell active mixer using a PHEMT transistor model in ADS. I've referred some articles of Gilbert cell active mixer design but I haven't found any matching circuit or ...
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Audio mixer, one output to multiple inputs
I'm trying to create a device that will take one stereo input and send it to 4 or more audio Bluetooth transmitters. This way, I can connect my prjoector to it and everyone watching can listen in on ...
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Volume gets lower when left and right audio channels are combined
I noticed that the volume of a speaker gets slightly lower when combining the left and right channels versus having ONLY one of the 2 channels connected to the speaker. I know that combining the left ...
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Why would a mixer output a signal when only LO is present and RF input is terminated?
I have a mixer with a liner frequency sweep going into the LO port, and a terminator on the RF port. I've noticed that this produces a significant signal at the output. It resembles what we would get ...
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What should be connected to pins 3 and 4 of this 1/4 inch mono jack?
What should be connected to pins 3 and 4 of this 1/4 inch mono jack?
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Simulating mixer phase detector in ADS using harmonic balance problem
There is a basic property of a mixer in which it could used as a phase detector as shown in the theory below.
A circuit was built where there two sources with same frequency but difference phase as ...
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How to set the output impedance of this circuit?
Assuming no biasing, would setting the Re to 300 Ω be the proper method of impedance matching?
simulate this circuit – Schematic created using CircuitLab
I figure that at some point, a ...
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RF mixer output
I have three questions with respect to an RF mixer. Let us consider this component - ADE-35MH+ from mini-circuits. The component has three pins - LO, RF, and IF.
What is the output on IF? Is it LO + ...
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Mixers and LO Harmonics
Say we have an RF signal with components at \$F_{LO}+\Delta\$ and \$3F_{LO}+\Delta\$ and we want to down-convert so that \$F_{LO}+\Delta\$ becomes \$\Delta\$. We will mix this RF signal with our local ...
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Master pitch control for oscillators
I’m doing a project of four oscillators where each one allows switching between a sawtooth or square waveform. The diagram that I attach is the corresponding one for a single oscillator, each one has ...
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Can I use the local oscillator and intermediate frequency pins as inputs on an HMC220B RF mixer?
My goal is to take an FM signal centered at 5.8 GHz and up-convert it to 6.5 GHz, amplify and transmit the signal, then down convert the received signal from 6.5 GHz to 5.8 GHz on the receiver side.
I ...
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In an audio mixer, when is it necessary to match the input impedance of other devices?
I found an audio mixer design that introduces a 47k resistor on each input.
Credit: Graham Lambert
According to the designer:
We want the input impedance presented to each input to be constant and ...
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Mixing a microphone and a amplified speaker to a vlog set up
I have a BT motorbike head set and I want to take both the microphone and the audio from the ear price to the GoPro microphone jack..
Reason is we use this for recoding our vlogs and it’s good to get ...
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Bias tee in Vector Network Analyzer
Can I use a bias tee in the back of a VNA (E5080B) as a port 1 and 2, or do I need a mixer for it? I want to measure the network parameters of a device that requires bias.
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Instrument level to line level and mixing
I would like to convert an instrument level (guitar) to a line level in order to feed the isd1820 sampler chip. What are my option in order of doing so?
In addition - I would like to mix the four ...
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Can I compress the dynamic range of ns pulses to better fit ADC range using log amp or mixer?
I have an experiment in which the signal I want to measure is a 1 ns pulse that occurs somewhere around 0-100 ns after a trigger. I want to digitize the pulses to extract the time they occurred and ...
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Frequency upconversion from 1 to 100 MHz for FM transmitter
I'm trying to build an FM transmitter like pifm but using the ESP32. I can generate an FM signal at the DAC output of the ESP32 with a carrier frequency of 1 MHz and a deviation of 25 kHz, but in ...
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Dangers of local oscillator signal being stronger than radio frequency signal in mixer
Recently as an interview question for an RF engineer job, I was asked the following question.
What are the dangers of having a local oscillator power level much higher than that of the RF power level ...
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Self-biasing diode in mixer applications
I am working to understand this application's mixer design note. An image of the mixer is shown below. It uses two transistors and a hybrid ring coupler (rat-race coupler).
What I am having trouble ...
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Why does this passive mixer have such a high noise figure?
Here is the circuit:
And here is the noise figure as a function of frequency:
It is a big value. Why?
You can see the passive mixer here:
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Push to talk mic over music
I have an amplified mic and I want to mix it with an mp3 player output. I tried something like this without a relay (just a button with 2 pairs of contacts), but I hear a pop when I press the button (...
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Sizing a mixer circuit
Here's the question:
Here's my attempt:
The table where i got the transistors values:
And here's the circuit i implemented in LTSpice:
The simulation results was a failure.... The output voltage ...
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What does \$\small-X(f+f_{LO})\$ mean in this passive downconversion mixer?
In the images below I circled one expression in red. There's supposed to be a frequency shift, but what does -X(f+fLO)/j·π mean here, and how is Y1(f) equal to the output spectra in figure 2.22(b)?
...
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Generating DC signal using a phase detector
I can generate a DC signal using a splitter and a phase detector. I do this by splitting a signal to two and then mixing them in a phase detector (I can also use a mixer as well for this purpose). By ...
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Audio mixer comments/concerns
I'm trying to design an audio mixer for my friend, and he only needs three stereo channels with volume for each channel as well as a master volume.
Additionally, he'd like as high an audio quality as ...
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Determining LO drive voltage for 13dBm mini-circuits mixer
I am interested in using the following mixer by mini-circuits: RMS25-MH+. In the datasheet it is specified that the required LO drive power is 13dBm.
As i understand it double balanced mixers use ...
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Mixer noise calculation
It is not clear for me how a mixer generates noise. Lets say that we take an up-converting mixer there is certain white noise level at LO input - \$N_{LO}\$ and a certain level of a white noise at RF ...
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What's the purpose of the band-pass filter in an RF transmitter?
What is the purpose of the marked band-pass filter?
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Relation between signal mixer and filters
Mixer output shown as red wave:
Can a band-pass filter be used to remove the low frequency shown as a blue sine wave and leave the rest high frequency just like the frequency shown as a green sine ...
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Clarification on I/Q Mixer output
I'm working on RF Receiver, it is required to use I/Q Mixer for IF downconversion. Specification as follows below
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FM transmitter won’t work. I need help with more gain, and current at the output
I am trying to make an FM transmitter circuit using cascaded transistors. My two input signals are from a microphone and from an 80 MHz crystal.
I’ve calculated a gain of 22 from the first stage and ...
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Mixer design : IF is +/- DC volts, local oscillator is cosine 9.6 kHz
I am working on a mixer which will be used for 4QAM, QPSK. The local oscillator is 9.6 kHz and the IF would be + or - 1 volt DC in order to have the RF port output either cosine or -cosine. Which ...
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Cost-efficient mixers and/or demodulators for low frequencies
I am working on a circuit project where I need an in-phase/quadrature mixer for acoustic signals in the range of 200 kHz. I have seen that there are a lot of ICs for radio frequencies that implement a ...
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Why does the IF of an RF mixer not go down to DC?
Consider this mixer:
“SMA Triple Balance Mixer RF/LO Freq. 6-18 GHz IF Freq. 2-8 GHz”
If my RF is 18 GHz and my LO is 17 GHz then the IF should be 1 GHz. But the product somehow has a minimum of 2 GHz....
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Help in smoothing signal output from a frequency mixer
I have a circuit with a TFM-3MH+frequency mixer. I need to output a low frequency signal of 10-100Hz.
The signals that I'm sending to the input ports from a signal generator are:
Sine wave of ...
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Where to add equalization in active audio mixer?
I want a 2-input summing amplifier where I can adjust the amount of signal from each source with a single potentiometer. I intend to hook up two microphones (Shure SM57 and Audio Technica ATR 1500, ...
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Need to mix an audio signal from a low power device, into a high power speaker
Basically, I want to take a cable going from the car audio amplifier to a speaker which is sending around 50W of power, that cable, and put a mixer in there, where I will inject an audio signal that I ...
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Overall Gain for Mixer Circuit
I am working on an audio mixer circuit for balanced studio gear. The circuit consists of two unity gain balanced line receivers (THAT1200), going into a pair of voltage dividers controlled by a shared ...
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Impedance transformer, how to measure
I am preparing to do some RF mixer experiments with the SA612 Gilbert cell mixer. I started out with the impedance matching as I understand that the input and output need to be matched. From what I ...
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Separate "voltage dividers" for multiple AC sources
Say we have two AC sources in a circuit. Is it possible to create separately control the output coming from each source using voltage dividers? (No op-amps)
E.g. So that you have $$V_{out}=aV_1+bV_2$$
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Is there a simple fix for summing 2 AC signals?
I have seen many mixer schematics. They are pretty much always the same - a stack of resistors.
Even some DJ mixers using the SSM2164 simply joined outputs followed by an opamp. The same thing always ...
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Measuring the amplitude of a nV signal of known frequency and phase using AD633
I am wondering if there is a circuit to measure the amplitude of a sinusoidal signal of known frequency and phase that is induced in a pickup coil. The amplitude would be in the range of 0nV to ...
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