Some RF receivers accept square wave clock reference (10MHz, 1pps, etc) and others accept sine wave. Most of the GPS do devices are outputting 10MHz sine wave timing signals. Are there practical or theoretical differences in the way these timing signals will contribute to the accuracy of time-stamped output samples? Which one is better?

2021年11月4日 · Complex multiplication of a (complex; I and Q components) input signal with Sine/Cosine as shift frequency results in a complex output signal. The problem is the generation of a square wave as complex signal: limited spectrum. Wait for a better explanation. $\endgroup$ –

2020年8月5日 · $\begingroup$ Thanks Phil, the main points i get from your answer is that a square wave is composed of many sine waves at every odd harmonic and that you can turn a square wave into a sine wave by using a low pass filter, and that using a BFO with harmonics will result in undesired frequencies appearing in the output of the mixer.

2013年10月23日 · Thus, we multiply the RMS voltage by twice the square root of two - a factor of about 2.828 or so: \begin{equation} 2\sqrt{2} = 2.8284271247.... \end{equation} Of course, the process also works in reverse - if you can measure the peak-to-peak voltage, dividing that by the same factor will give you the RMS voltage assuming a perfect sine wave.

For example, a square wave consists of some fundamental frequency, plus all its odd harmonics. A sawtooth wave has even and odd harmonics. Each of these harmonics will generate mixing products, just as if you fed in a sine wave at that harmonic frequency.

2018年1月26日 · I'm not really too technical when it comes to radio, but I understand that in AM, a shortwave radio generates the carrier frequency so that it can mixed with the received station and then removed, leaving the signal which was modulated with the carrier wave during broadcast. What's keeping the two carrier waves (broadcaster and receiver) in sync?

2021年1月6日 · For example PSK31 uses a cosine envelope, meaning in the case of alternating between phases it multiplies the carrier not by a square wave, but rather by a cosine. Since a cosine consists of just one frequency component, this generates not an infinite series of frequency components in the output of the mixer, but just two: the carrier frequency ...

2015年9月23日 · This would only apply to the extent that the transmitted waveform has an RMS average equivalent to a sine wave. For example consider that a square wave has a higher RMS average, and thus a higher power, than a sine wave of equal amplitude. In practice the difference will be small or nonexistent for most modulations.

A half-wave dipole doesn't maximize that parameter, even among dipoles; it increases until roughly 1.25 wavelengths, then decreases, then generally increases again, in an oscillating way. There are nice things about half-wave dipoles (a convenient, easily-matched impedance and a simple pattern without lobes), but it doesn't maximize gain or ...

2015年7月8日 · Voice doesn't have a "carrier wave". It simply contains the up and down level of the voice. Where the sound wave is 0 is effectively the carrier. Typical AM signals take this signal, and modulate it with the carrier wave. Thus, the signal has a large peak at the peak of the carrier wave, and a relatively small part of the signal is everything else.