
Contents
Annex A
OPTION 11 FAST PULSE MODULATION
General description
Option 11 adds the ability for the instrument to internally generate a fast pulse modulated waveform from logic levels applied to the PULSE INPUT socket. The pulse modulator is suitable for generating fast pulses with high isolation for applications in radar and EMI. It may be used in conjunction with other forms of modulation to form composite signals. Familiarity with normal operation of the signal generator is assumed.
Operation
Fast pulse modulation is automatically applied when Option 11 is fitted.
Acceptance testing
The following acceptance tests supersede those given under Pulse modulation in Chapter 5.
Pulse modulation
Specification
Pulse modulation |
|
Carrier frequency range | 100 kHz to 2.4 GHz, usable to 9 kHz. |
RF output range | As standard instrument, with the exception that maximum output level |
| is reduced by 3 dB when pulse modulation is enabled. |
RF level accuracy | Additional ±0.01 dB/°C temperature coefficient when pulse modulation |
| enabled. |
| Adds ±0.25 dB for carrier frequencies below 10 MHz. |
On/off ratio | >80 dBc below 1.2 GHz; |
| >70 dBc up to 2.05 GHz (typically >80 dB); |
| >65 dBc up to 2.4 GHz (typically >70 dB at 2.4 GHz). |
Rise and fall time | <20 ns, typically 15 ns. |
Maximum repetition frequency | 10 MHz. |
Control | 50 Ω input impedance. A logic ‘1’ (2 to 5 V) turns the carrier on, a |
| logic ‘0’ (0 to 0.8 V) turns the carrier off. Maximum input is ±10 V. |
Test equipment |
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Alternative equipment may be used providing it complies with the stated minimum performance.
Description | Minimum specification | Example |
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Power meter | ±0.1 dB from 9 kHz to 2.4 GHz | IFR 6960B and |
|
| 6912 |
Spectrum | Frequency coverage 100 kHz to 2.4 GHz | AnritsuMS2602A |
analyzer |
|
|
50 Ω load | 1 W, 50 Ω nominal impedance, DC to 2.4 GHz | Lucas Weinschel |
(termination) |
| M1404N |
Oscilloscope | 100 MHz bandwidth | Tektronix |
|
| TDS 220 |
Function | DC to 10 kHz square wave | HP 3325B |
generator |
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RF detector | 100 kHz to 2 GHz | HP 8471D |
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