A21 Source Multiplier/Amplifier 50 (Soma 50) (E8363A And E8364A Only) - Agilent Technologies E8362A Service Manual

Theory of Operation
Source Group Operation
In bands 1–3, the 3.845 to 6.8 GHz output of the YTO and the 3.8 GHz output of the PMYO
are mixed to produce the 45 MHz to 3.0 GHz output frequency that is sent to the
multiplier/amplifier 20 (MA 20). In bands 4–25, the 3 to 10 GHz output of the YTO is
filtered and sent directly to the MA 20.
Multiplier/Amplifier 20 (MA 20)
The MA 20 filters, amplifies, and passes through, the 45 MHz to 10 GHz output
frequencies in bands 1–10. The signals for bands 11–25 are doubled, filtered, and
amplified. Together, these two paths produce an output frequency range of 45 MHz to
20 GHz.
For the E8362A analyzer, this signal is sent directly to the A22 switch splitter in the signal
separation group.
For the E8363A and E8364A analyzers, this signal is sent to the A21 source
multiplier/amplifier 50 (SOMA 50).
A portion of this output signal is split off and combined with other inputs in the ALC
circuitry to control the output power level.
ALC Circuitry
The following inputs are combined in the ALC circuitry to produce a signal that is sent to
the MA20 to control its output power level:
• output of the MA 20
• temperature compensation
• slope compensation
• power level DAC
• 1V/GHz signal from the A11 phase lock board
A21 Source Multiplier/Amplifier 50 (SOMA 50) (E8363A and E8364A
Only)
The A21 SOMA 50 consists of three signal paths:
• In the first path, the 45 MHz to 20 GHz source signals for bands 1–15 are amplified,
leveled, and passed through to the A22 switch splitter.
• In the second path, the 10 to 20 GHz signals for bands 16–22 are doubled, filtered, and
amplified to produce the 20 to 40 GHz output.
• In the third path, a portion of the second-path signal is doubled to produce the 40 to
50 GHz output.
The source ALC circuitry (located on the A16 test set motherboard) provides feedback to
the SOMA 50 to control the output power level.
5-10
PNA Series Microwave Network Analyzers
E8362A, E8363A, E8364A
Service Guide E8364-90001