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For communication signals, a Root Raised Cosine (RRC) filter is often used as the pulse shaping filter. What kind pulse shaping filters (prototypes or window functions or tapers) are used in radar waveform design to reduce range sidelobes?

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On transmit, big amplitude tapers are very rarely used on larger radar systems. This mostly just boils down to the electronics: for the sake of power efficiency, transmit amplifiers are typically kept in compression, and as such they need constant envelope waveforms. There’s usually some slight shaping done on transmit to reduce spurs, but not really for range sidelobes. Now for smaller systems that can operate in the linear region of the amplifiers, sure you could do some shaping there if you’d like at the cost of some transmit power.

Sidelobe weighting is going to come in during pulse compression and Doppler processing. Taylor windows are typically the most popular for range compression due to the control they give, and most systems I’ve worked on do a Chebyshev or similar weighting for Doppler. Chebyshevs ar popular since you can just floor the sidelobes down to your phase noise specification nice and flat, which is your limit on your weighting function anyway.

Ultimately it’s going to come down to hardware specs and performance requirements though!

Source: radar design engineer

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That depends on what you want to achieve!

Windows and pulse shapes are always trade-offs between bandwidth, time-limitedness, energy in the first sidelobe, overall energy in all sidelobes, speed of sidelobe decay...

And all these might or might not be relevant in your application.

For example, I remember a Chebybyshev shape being very desirable for resolving multiple separate close targets, because it makes guarantees about the maximum side lobe height; in a different application, you might not care about the maximum side lobe, as that will be close to your main lobe, anyway, but about quickly decaying side lobes so that you can detect targets that are further away, but share the same Doppler. Slepian, then, maybe, or simply a Kaiser window.

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  • $\begingroup$ I'm guessing that you'd want a filter shape that you can specify the 3dB cutoff frequency as an input to calculating the taps? $\endgroup$ Nov 9, 2021 at 17:23
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    $\begingroup$ so far, 3dB bandwidth specifically has been irrelevant to any radar system I've touched; other measures of bandwidth were. As explained above, the parameters you'll choose depend on your radar system's needs. $\endgroup$ Nov 9, 2021 at 17:33

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