Anritsu MG3690A manual If Up-Conversion Option, User-Defined Modulation Waveform Software Option

IF Up-Conversion (Option 7)

Option 7 adds an internal mixer that can be used for the generic up-conversion of an IF signal. The mixer’s RF, LO, and IF ports are made available at the rear panel of the MG3690A, via three female K-Connectors. The typical application will feed the MG3690A microwave output, which can be moved to the rear panel via option 9K, to the mixer’s LO port. An external IF signal will be fed to the mixer’s IF port. The new up-converted signal will be available at the mixer’s RF port.

Mixer Type	Double Balanced
RF, LO Range	1 to 40 GHz
IF Range	DC to 700 MHz
Conversion Loss	10 dB Typical
Max Power into any Port	30 dBm
Isolation, RF to LO	23 dB
LO Drive Level (recommended)	+10 to +13 dBm
Input P1dB	+3 dBm Typical

The IF Up-Conversion option is particularly useful to create a microwave frequency IQ-modulated signal. Lower frequency IQ-modulated RF sources are readily available, such as the Anritsu MG3681A. Option 7’s IF input can be used to feed in an IQ- modulated signal from an MG3681A, up-converting it to as high as 40 GHz with an MG3694A. A typical setup is shown below.

User-Defined Modulation Waveform Software (Option 10)

An external software package provides the ability to download user-defined waveforms into the internal LF Generator’s (Option

23)memory. The MG3690A provides as standard with the LF Generator sinusoidal, square-wave, triangle, positive ramp, Gaussian noise, and uniform noise waveforms.

MG3681A

IF RF

MG3690A

IF Up-Conversion Application and Setup

Two look-up tables of 65,536 points can be used to generate two pseudo-random waveforms, one for amplitude modulation and the other for frequency or phase modulation. The download files are simple space-delimited text files containing integer numbers between 0 and 4095, where 0 corresponds to the minimum modulation level and 4095 the maximum.

In addition to the capability of downloading custom waveforms, the software offers a virtual instrument modulation panel. Custom modulation setups with user waveforms can be stored for future use. For IFF signal simulation, the internal generators can be synchronized. They can also be disconnected from the internal modulators, making the low frequency waveforms available at the rear panel for external purposes.

One application of this feature is storing an antenna pattern wave form in memory and using it to feed the external input to the scan modulator, Option 20.

Scan Modulation (Option 20)

Option 20 adds a microwave linearly controlled alternator to provide deep AM capability. This modulator is inserted outside the leveling loop but before the optional step alternator. It is switched in and out of the RF path. Scan modulation is driven externally only.

Frequency Range	2 to 18 GHz
Attenuation Range	0 to 60 dB
Flatness	±2 dB, 0 to 40 dB
	±2 dB, 40 to 60 dB
Step Response	< 1 ms
Sensitivity	-10 dB/V
Insertion Loss	< 6 dB (when engaged)
Input	Rear Panel BNC connector
	High Impedance

TRACE A: Ch1 8PSK Meas Time

1.5

I - Q

300 M /div

-1.5

-1.9607643757 1.96078437567

Carrier Frequency = 38.000 GHz

10