Radar signals can broadly be classified as

• Pulse signal
• Chirp signal
• Frequency-hopping signal

The FCC/ETSI/JP and other regulatory bodies define their own version of the above signals. Below is given an overview of FCC signals and their widths and also provide minimum percentage number of successful detection of the radar signal for the FCC to approve the device under test.

For a more comprehensive list – refer the link below

http://linuxwireless.org/en/developers/DFS/index.html

Pulse Signals

The Pulse signals are provided below for reference

PRI stands for pulse repetition interval

Radar Type	Pulse Width (μsec) in 0.1 μsec steps	PRI (μsec) in 1 μsec steps	Number of  pulses	Minimum Percentage of Successful Detection	Minimum Number of Trials	Unique waveforms required
1	1	1428	18	60%	30	No
2	1-5	150-230	23-29	60%	30	Yes
3	6-10	200-500	16-18	60%	30	Yes
4	11-20	200-500	12-16	60%	30	Yes
Aggregate (Radar Types 1-4)				80%	120

Chirp Signals:

NOTE: To understand about chirp signals – refer wikipedia link –

https://en.wikipedia.org/wiki/Chirp

The Chirp signals are 12 second long. The 12 second long interval can have 8-20 radar bursts. Based on the number of bursts, the 12 second interval is further subdivided into equal intervals and each interval contains 1-3 pulses.

The starting time of a pulse within an interval and the PRI between pulses are chosen randomly such that each burst is confined to its respective interval. The pulse width of a pulse in a particular burst will have the same pulse width. The pulses in different bursts can have different pulse widths.

Each pulse has linearly-modulated, symmetrically centered chirp signal. All pulses in a burst have the same chirp width. Pulses in different bursts can have different chirp-widths.

Radar Type	Pulse Width (μsec) in 0.1 μsec steps	Chirp Width (MHz) In 1 MHz Step	PRI (μsec) in 1 μsec steps	Number of Pulses per Burst	Number of Bursts	Minimum Percentage of Successful Detection	Minimum Number of Trials
5	50-100	5-20	1000-2000	1-3	8-20	80%	30

Frequency-hopping signal:

Frequency hopping signal consists of a periodic sequence of non-repeated hopping frequencies (in step of 1 MHz) hopping of a frequency band of 475 MHz.

274 sets of unique hopping patterns are used for a 300ms transmission.  Such a 300ms transmission contains 100 hops and it is possible that none of these hops fall in the frequency band where a WLAN node is active.

Radar Type	Pulse Width (μsec)	PRI (μsec)	Pulses per Hop	Hopping Rate (kHz)	Hopping Sequence Length (msec)	Minimum Percentage of Successful Detection	Minimum Number of Trials
6	1	333	9	0.333	300	70%	30

Radar Signal detection in driver