Questions tagged [modulation]
Generic term for coding information onto a carrier signal.
528 questions
3 votes
1 answer
238 views
IR optical receiver system circuit
I'm trying to build a device to measure the obscuration of an IR signal in a free air chamber that will be a few meters accross, between 10 - 50m aprox. This will be used to determine if there are ...
- 105
0 votes
2 answers
96 views
Dual Channel RF Synthesizer with Frequency Sync Capability
I have an application involving modulation/demodulation with a 20-40 MHz frequency that I need to apply in two places with controlled phase offset. I usually do this with something like the Rigol ...
- 9
0 votes
2 answers
302 views
Help Explaining Single Sideband (SSB) vs. Double Sideband (DSB) Diagrams
I am really struggling to understand intuitively what is happening in single vs double sideband. My textbook has provided some diagrams but extremely lackluster explanations, and was hoping someone ...
- 461
3 votes
4 answers
438 views
What is the easiest way to make frequency modulation between two sine waves?
I'm trying to get hands-on some circuits that I studied mathematically. First by making them on SPICE, then on a breadboard. I'm struggling finding the circuit, or even maybe the component, that can ...
- 163
1 vote
1 answer
98 views
Modulation on SPI interface
I recently have faced an interesting phenomenon on the SPI lines. The SPI clock freq is 25MHz and it's modulated on a ~13Hz waveform similar to a saw tooth and looks like an exponential capacitor ...
- 11
0 votes
1 answer
136 views
What really happens inside ADC chip? [closed]
I know analog signal is input and output of ADC is 0100100001... Wikipedia and other sites shows me a graph of Digital out vs. analog in. I am mature enough to ...
-1 votes
2 answers
139 views
I don't understand how QPSK modulation is involved with or assists in carrier suppression
https://www.allaboutcircuits.com/technical-articles/quadrature-phase-shift-keying-qpsk-modulation/ https://www.allaboutcircuits.com/textbook/radio-frequency-analysis-design/radio-frequency-...
0 votes
1 answer
132 views
Why frequency deviation in BLE 1Msym is different than BLE 2Msym?
From Bluetooth Core spec: The modulation is Gaussian Frequency Shift Keying (GFSK) with a bandwidthbit period product BT=0.5. The modulation index shall be between 0.45 and 0.55. A binary one shall ...
- 137