Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [frequency-synthesis]

21 questions
16
votes
3 answers

Why do microwave ovens use magnetrons?

With a lot of advancement in solid state electronics and signal manipulation, isn't it easier to simply take high amplitude signals with frequencies near 1 MHz and multiply the signals using diodes and frequency filters(LC/RLC) than to use a…
Vishwa Mithra Tatta
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12
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4 answers

How do digital function generators generate precise frequencies?

I was designing an electronic circuit that requires precise frequency control when I realized how much I don't know about the frequency synthesis itself. For example, when I take my low-end 2-channel arbitrary waveform generator, I'm able to set one…
user17152
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5
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1 answer

Help to translate jitter design constraint in a frequency synthesizer design with 4046 and 4017 ICs

I'm trying to design a frequency synthesizer with the old-school 4046 and 4017 ICs, with a scaling factor N = 1,5,7,10. The input signal is a square wave with adjustable frequency from 1 kHz to 10 kHz. I want to get a time jitter < 1% of the…
C.Slade
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4
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5 answers

Fast (high) frequency hopping with off-the-shelf components

I am looking for the easiest solution to synthesize 1.6 - 2.4 GHz (qudrature) in steps of 4 MHz settle within 10-50ns precise timing control when to switch frequency (e.g., at rising edge of an external signal, frequency should be updated) total…
divB
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3
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3 answers

Frequency Synthesis from 1MHz to 800MHz

I've been trying to plan out a new project for a while. It's a wideband antenna anaylyzer for radio applications. I've figured out most of the details, but the most important part - the frequency source - has me stumped. I'm trying to figure out the…
Patrick
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2
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4 answers

How to get a high precision sine wave not available from standard crystal?

I am considering for a RFID transmitter, which just send power with no data. However, my frequency is not standard 13.56MHz not 27.12MHz, it is 27.095MHz. Can I use the block diagram shown above? If yes, where can I get the 27.095MHz signal…
iouzzr
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2 answers

Is it feasible to synthesise sound with analog circuitry these days?

A friend of mine who is a layman in terms of electronics asked me to teach him how to synthesise audio with some analog circuit and how to build it. For some reason it has to be analog. Probably because that's so cool these days. I don't really get…
Magic Smoke
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4 answers

Is an MPU capable of equal quality digital synthesis as a dedicated DSP chip?

Is there any factor which would cause a modern microprocessor ( such as an ARM Cortex A/M ) to be inferior at performing digital synthesis compared with a dedicated DSP chip of comparable speed? At a glance, it looks like most digital synthesizers…
ajxs
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1
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RF frequency synthesis - how low power can I reasonably go?

I'm an undergrad working on the analog frontend for a student-developed cube satellite. After looking at the options, I've decided to use the CML Microcircuits CMX994 for the receiver and the CMX998 for the transmitter. I chose the 994 for the RX…
Synchrondyne
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0
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1 answer

N Fractional PLL spectrum

I'm studying the different types of N-fractional PLLs based on switching between two or more frequencies to get the desired frequency. However, I'm facing difficulties to understand how the output spectrum can be basically a predominant tone on the…
Fernando
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Disadvantages of DLL clock generators compared to PLL

I've been learning from many publications that DLLs offer various advantages over PLLs, such as low-jitter performance and fast locking. So, recently, DLLs have been used for local clock generation in various applications too (edge combining DLL or…
Andrea Toffanin
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1 answer

Does imposing an odd initial condition reduce spurs in MASH Delta-Sigma Modulators that has second order stages?

I've been reading about how fractional spurs can be reduced in a Digital MASH Delta Sigma Modulator (especially for application with a fractional-N PLL) by having the initial condition of the first stage be set odd (typically by just setting the LSB…
Jack
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How to choose between different equivalent PLL/divider configurations?

If there are multiple ways to get the required clocks for a given CODEC, how do you choose between them? For example, if a CODEC can accept 64fs, 128fs, 256fs, and has an internal PLL that can generate any of these, why choose one configuration over…
endolith
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What is the difference between a PLL and a frequency-synthesizer？

It seems that a LPF is contained in PLL and not in frequency-synthesizer. Maybe I had made a wrong judgement.
wu yi
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Are there still programmable clock synthesizers with single ended TTL output leves (in 2019)?

I'm looking for a clock synthesizer IC that can drive my vintage 5V NMOS CPU in the range of 5 - 50MHz. The granularity would preferably be in the range of 100kHz or less. All I can find when searching the net are contemporary devices that have…
Eriond
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