External Mixer

Other topics about Measurement Using E5053A and External Mixer

This section describes settings and limitations when using the external mixer.

Overview

The E5053A Microwave Downconverter with the external mixer connected enables measurement up to 110 GHz.

Setting the E5052B when used with the E5053A Microwave Downconverter and the external mixer is based on the frequency of the RF signal ( IF signal of the downconverter) supplied to the E5052B.

Setup Parameters

The settings of the external mixer are common to all measurement modes (phase-noise measurement, spectrum monitor measurement, frequency/power measurement, and transient measurement).

The settings are applied to the hardware immediately when the device configuration is C in Device configuration using E5052B and E5053A and the external mixer is on.

Other than the phase-noise measurement mode, use the identical LO frequency for each channel (channel 1 and channel 2), while the LO frequency of channel 1 and channel2 can be set differently.

In the phase-noise measurement mode, the carrier frequency is measured using the channel2 path. In the frequency/power/DC current measurement, the carrier frequency is measured using the channel1 path.

Both channel paths are required to complete the measurement other than spectrum monitor mode, which uses channel2 path only.

In the transient measurement mode, the channel1 path is used for the wideband transient measurement, and the channel2 path is used for the narrowband transient measurement.

The settings when using the downconverter and the external mixer include:

Setting of LO

Set the external signal source (LO).

(Channel 1 side)

System > Instrument Setup > Downconverter Manual Setup > LO1 Frequency

System > Instrument Setup > Downconverter Manual Setup > LO1 Level

(Channel 2 side)

System > Instrument Setup > Downconverter Manual Setup > LO2 Frequency

System > Instrument Setup > Downconverter Manual Setup > LO2 Level

Allowable range of the LO frequency setting is 2.975 G - 10.025 GHz, and setting resolution setting is 50 MHz.

Allowable range of the LO level setting is 10 - 16 dBm when the setting frequency is 2.975 G - 6 GHz; it is fixed to 10 dBm when the setting frequency is 6 G - 10.025 GHz.

Setting of DC Bias Current

Set a bias current supplied to the external mixer.

(Channel 1 side)

System > Instrument Setup > Downconverter Manual Setup > Mixer 1 Bias

System > Instrument Setup > Downconverter Manual Setup > Current

(Channel 2 side)

System > Instrument Setup > Downconverter Manual Setup > Mixer 2 Bias

System > Instrument Setup > Downconverter Manual Setup > Current

Valid input range of the bias current is -10 mA to 10 mA both for Channel 1 and Channel 2.

Setting of downconverter IF Gain

Set IF gain inside the downconverter.

(Channel 1 side)

System > Instrument Setup > Downconverter Manual Setup > IF Gain 1

(Channel 2 side)

System > Instrument Setup > Downconverter Manual Setup > IF Gain 2

Valid input range of the downconverter IF gain is 0 dB to 35 dB both for Channel 1 and Channel 2.

Setting of downconverter  ΔIF Frequency

Set frequency difference when the IF frequency (RF frequency of the E5052B) of the downconverter differs between Channel 1 and Channel 2.

System > Instrument Setup > Downconverter Manual Setup > ΔIF = IF2 - IF1

Set the value ΔIF obtained by the following equation.

ΔIF = IF (Channel 2) - IF (Channel 1)

 

Limitations

Using the external mixer has following limitations:

When the external mixer is enabled, the auto frequency control function (AFC) is not available. Also not available is the carrier search function.

When using the external mixer, values are not changed automatically so the settings should be done manually

For example, when you make measurement in analyzer mode for frequency/power measurement, if the measurement frequency exceeds a valid measurement range during a sweep, LO frequency of the downconverter is not changed automatically. (The frequency is not changed automatically to follow the excess of frequency.)