In Japan DFS requirements, the radar waveform parameters are different for the frequency band 5250 ~ 5350 MHz (W53) and 5470 ~ 5725 MHz (W56).
In W53 band, there are two fixed pulse sequences to emulate weather radar.
| Test Signal | Pulse Width (μs) | Pulse Repetition Frequency (Hz) |
Number of Continuous Pulses |
Repetition Cycle (s) |
|---|---|---|---|---|
|
Fixed pulses 1 |
1.0 | 700 | 18 | 15.0 |
| Fixed pulses 2 | 2.5 | 260 | 18 | 15.0 |
In W56 band, there are three fixed pulse radar test waveforms, three variable pulse radar test waveforms, one chirp radar test waveform and one frequency hopping radar test waveform.
Fixed Pulse Radar Test Waveform
Variable Pulse Radar Test Waveform
Frequency Hopping Radar Test Waveform
| Test Signal | Pulse Width (μs) | Pulse Repetition Frequency (Hz) |
Number of Continuous Pulses |
Repetition Cycle (s) |
|---|---|---|---|---|
|
Fixed pulses 1 |
0.5 | 720 | 18 | 15.0 |
| Fixed pulses 2 | 1.0 | 700 | 18 | 15.0 |
| Fixed pulses 3 | 2.0 | 250 | 18 |
15.0 |
| Test Signal | Pulse Width (μs) | Pulse Repetition Frequency (Hz) | Number of Continuous Pulses | Repetition Cycle (s) |
|---|---|---|---|---|
| Variable pulse 4 | 1~5 | 4347~6667 | 23~29 | 15.0 |
| Variable pulse 5 | 6~10 | 2000~5000 | 16~18 | 15.0 |
| Variable pulse 6 | 11~20 | 2000~5000 | 12~16 | 15.0 |
| Test Signal | Pulse Width (μs) | Chirp Width (MHz) | Pulse Repetition Frequency (Hz) | Number of Continuous Pulses | Repetition Cycle (s) | Number of Bursts |
|---|---|---|---|---|---|---|
| Chirp | 50~100 | 5~20 | 500~1000 | 1~3 | 12.0 | 8~20 |
To generate the Chirp radar test waveform, N7607B Signal Studio for DFS Radar Profiles software uses the parameter structure as below. You can see that in each waveform, there are a number of bursts, with the number randomly chosen from 8~20. And in each burst, there are parameters like bust offset, PRI-1, PRI-2, etc. Figure 2 shows the relationship of these parameters. Burst offset is randomly chosen in the range from 1 μs to (Burst Period – (PRI-1) – (PRI-2) – (PRI-3)).
Figure 1. Parameter Structure for Long Pulse Radar Test Waveform Generation
Figure 2. Graphical Representation of Relationship for Parameters in Each Burst
| Test Signal | Pulse Width (μs) | Pulse Repetition Frequency (Hz) | Number of Continuous Pulses | Burst Interval (ms) | Repetition Cycle (s) | Hopping Sequence Length (ms) |
|---|---|---|---|---|---|---|
| Hopping | 1.0 | 3000 | 9 | 3 | 10.0 | 300 |
Refer to Simulated Frequency Hopping Generation for more details of how the frequency hopping radar signals are generated in the signal generator.