A56 Test Port 1 Option 029 Switch; A64 Test Port 1 Option 029 Tuner; A57 Test Port 2 Option 029 Switch; A59 Noise Receiver (Downconverter) - Keysight Technologies N5244/5B Service Manual

Theory of Operations
Noise Measurement Group Operation (Option S93029A)
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A64 Test Port 1 Option 029 Tuner

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A57 Test Port 2 Option 029 Switch

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A59 Noise Receiver (Downconverter)

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A9 Noise Receiver Board

A56 Test Port 1 Option 029 Switch

The A56 bypass switch is placed in the Port 1 source path, allowing the source
signal to be switched between normal test mode configuration and internal
noise tuner configuration.
A64 Test Port 1 Option 029 Tuner
The A64 internal tuner is placed in the Port 1 source path together with the
Port 1 switch. The internal tuner is used to vary the Port 1 transmission line
impedance during a noise figure calibration. This enables the source port to be
fully vector corrected during subsequent noise figure measurements.
A57 Test Port 2 Option 029 Switch
The A57 bypass switch is placed in the Port 2 source path, allowing switching
between normal test mode configuration and noise figure measurement mode.
When the PNA-X is switched into noise figure measurement mode, the switch
allows both the source incident signal and the noise incident signal from the
DUT to simultaneously pass through to the A59 noise receiver
(downconverter).
A59 Noise Receiver (Downconverter)
The A59 noise receiver (downconverter) contains an input Low Noise Amplifier
(LNA), an RF Filter Bank, an LO Filter Bank, and a mixer. For 6 – 50 GHz
signals, the LNA provides the necessary gain to enable measurements on low
noise and low gain devices. The signals are routed through the RF Filter Bank
where the noise signal is filtered for third harmonic conversion rejection. The
noise signals are mixed with the LO synthesized signal to produce IF noise
signals before being sent to the A9 Noise Receiver board. For frequencies
between 10 MHz – 6 GHz, the noise signals bypass the A59 noise receiver
(downconverter), going to the A9 noise receiver board, where the signals are
amplified, filtered, and mixed with the LO synthesized signal to produce the IF
noise signals.
A9 Noise Receiver Board
In the A9 noise receiver board, the IF noise signals from the A59 noise receiver
(downconverter) are further amplified and filtered before being sent to ADC for
sampling. The 10 MHz – 6 GHz noise signals that passed through the A59
noise receiver (downconverter) are amplified, filtered, and mixed with the LO
Keysight N5244B/45B Service Guide 5-63