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That's the plan!

You are welcome!

You have a very valid point! Indeed, you can consider the denominator of CMRR either as common-mode-to-common mode gain or common-mode-to-differential-gain. This difference is only when the output is differential. You can use both to demonstrate different effects. 1) common-mode-to-common mode gain would be used when we want to show the ability of the stage to suppress common mode disturbances; 2) common-mode-to-differential-gain would be used when we want to show the ability of the stage to prevent common-mode disturbances injected into the signal. The latter point 2) is much more valid (your point), since ultimately we want to preserve the quality of the differential signal. Point 1) can be also valid if the stage is loaded with circuits that are sensitive to common-mode variations. So, the definitions should be either explicitly made or interpreted in the given context. If we consider the problem (as an exercise) it makes only sense if we consider common-mode-to-common-mode gain, since common-mode-to-differential gain is always 0 (if there is no mismatch). Since a learning objective of this exercise is to show that the time-constant at the common-node of the input pair transistors (Vs) is only relevant for common-mode signals and creates a pole only for common mode signals (and not for differential), we use here the definition 1) common-mode-to-common mode gain.

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Ok. Thanks you.

Hi, This should be easy. Just google my name and you will find my email address.

Thanks

The time constant K1=K2 should be changed, which means changing Cp1*R1 and Cp2*R2 (and R9)... You can for example choose for larger resistors and the tunability you can realize either with varactors (voltage controlled capacitance) or with a bank of parallel capacitors, which you can connect/disconnect via switches. However, for an oscillator with more phase shifted outputs, like four or more, I would consider another architecture. For example the phase-shifting or Bubba oscillators can do the job. The amplitude, like 1-2V p-p is not an issue. It can be fixed by changing the limiting circuits or we can have a cascaded stage with variable gain.

Btw, why the range profile looks noisier at 6:34 compared to the same plot but when two PMCW have the same code?

The interference depends on the code. The number of receiver will determine the power of the signal that is received. So, you will suppress the interferers but it is possible that you get cross-correlation and the noise floor rises up. However, this is solvable by using Hadamard code on top of APAS en.wikipedia.org/wiki/Hadamard_code

@@SimmySimmy Due to cross correlation. Check my other reply on how to solve this.

I think yes. This is the principle of digital communication and hence it can be used at any frequency. A carrier frequency of 10GHz can still provide cm range accuracy. The baseband will be limitted, say 100MHz which will limit the accuracy for the simple radar 1Tx-1Rx but you can easily use MIMO principles and get back the accuracy to cm levels. We are actually doing this in the lab. See: ruclips.net/video/wZHYMDzN4P4/видео.html

I think yes. There are many excellent innovations in FMCW radar, which enable MIMO. What we see in this video is the baseline. There are also innovations in PMCW. You may want to check our next step here: ruclips.net/video/wZHYMDzN4P4/видео.html

Excellent question! Thanks. At high frequency the effective number of bits decrease. This chip maintains about 11-12 effective number of bits up to 5MHz. Beyond this frequency the dynamic errors kick in and the effective number of bits drops. So, even if we choose 12bits in resolution, the effective number of bits beyond 5MHz will still drop under 11b. In the book: www.springer.com/gp/book/9789400703469 another test chip is measure with similar calibration and shows 13 effective number of bits at low frequencies.

I agree. Here is a very linear circuit that gives harmonic better than -80dBc: ruclips.net/video/Y9VmcfV_JbU/видео.html

Thanks! I used very standard 0.6V PN-junction diodes. the amplifiers are the standard uA741... in this video, you can see the data sheet ruclips.net/video/FsYbBPjAV2w/видео.html