Annex-A-1
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
Alternative equipment may be used providing it complies with the stated minimum performance.
Description Minimum specification Example
Power meter
±0.1 dB from 9 kHz to 2.4 GHz
IFR 6960B and
6912
Spectrum
analyzer
Frequency coverage 100 kHz to 2.4 GHz AnritsuMS2602A
50 Ω load
(termination)
1 W, 50 Ω nominal impedance, DC to 2.4 GHz
Lucas Weinschel
M1404N
Oscilloscope 100 MHz bandwidth Tektronix
TDS 220
Function
generator
DC to 10 kHz square wave HP 3325B
RF detector 100 kHz to 2 GHz HP 8471D
