Chirp Timing and Frequency

A chirp signal is characterized by three fundamental parameters: time, frequency, and slope.

 

 

 

 

1. Timing Parameters

The Total Duration of a chirp, also known as the Chirp Cycle, represents the complete time required for one waveform cycle.

It is the sum of four timing parameters: Start time, Ramp-up time, Ramp-down time, and Stop time.

 

 

 

Chirp Cycle/Period	Remark
	ex) T_chirp=1000 us, T_START=20 us, T_UP=420 us, T_DOWN=150 us, T_STOP=410 us

 

 

 

 

2. Frequency Parameters

The Total bandwidth of a chirp, also known as the chirp bandwidth, represents the complete spectral range covered by the waveform.

It is primarily determined by two frequency parameters: Start frequency and Stop frequency.

 

 

 

 

Chirp(RF) Bandwidth	Remark
	Chirp bandwidth is directly related to the range resolution of a radar system. ex) B_RF = 24.25 – 24.05 = 0.20 GHz = 200  MHz

 

 

 

 

 

3. Chirp Slope

The Chirp Slope represents the rate of frequency change over time.

While a steeper slope allows for finer range distinction, it also influences the maximum distance the system can effectively measure.

 

 

 

 

Chirp Slope	Remark
	With a fixed baseband bandwidth, the slope determines the maximum measurable range inversely. ex) S = 0.476 MHz/μs   , B_RF=200MHz, T_UP =420 us