Model 350S1G6A
28
Rev C
3.2.2
A2, A8-A15 Driver Amps (Schematics 10035763, 10039088,
10035766)
The Driver Amp RF section is assembled on thin film substrates and the bias control and fault circuitry is
assembled on a multi-layer printed circuit board. It has two (2) GaN amplifier sections. Each section is input
and output DC isolated by coupling capacitors. A 90
˚
quad coupler combines the RF outputs. 50Ω
termination resistors absorb any difference signals and help to improve the input and output VSWR of the
module. The module has a gain of approximately 10dB and delivers 10-15 watts of RF power. Active bias
circuitry regulates the DC current through RF devices. The nominal DC current for this amplifier is
approximately 3.0A from a 25.7V supply. Logic low voltage on the fault pin indicates a low or high current
condition exists on GaN FET 1 (bottom) or FET 2 (top).
3.2.3
A2 through A55 Output Power Amplifiers (Schematics
10035763, 10039088, 10035766)
The output power amplifiers are identical in construction and performance to the driver amplifiers described
in Section 3.2.2.
3.2.4
A3 Two-Way Splitter
The Two-Way Splitter is a multi-section, broadband, Wilkinson splitter. The input signal is split into two
equal-amplitude, equal-phase signals. The amplitude of each signal is 3-3.5dB below the input signal when
both outputs are terminated into 50
Ω
loads.
3.2.5
A6, A7, A16, A18, A19, A20, A21, A23 Four-Way Splitter
The Four-Way splitter is a multi-section, broadband, Wilkinson splitter. The input signal is split into four
equal-amplitude, equal-phase signals. The amplitude of each signal is 6–6.5dB below the input signal when
both outputs are terminated into 50Ω loads.
3.2.6
A56, A57 Twelve-Way Combiner
A56 & A57 are Twelve-Way radial combiners with impedance-matching. When the outputs of the 24 quad
amplifiers are fed to each 12-way combiner, the combined output will be approximately 10.8dB above the
output of a single quad amplifier.
3.2.7
A58 Two Way Combiner
A58 is a Two-Way radial combiner with impedance matching. When the outputs of the two 12-Way
combiners are fed to the Two-Way combiner, the combined output will be approximately 3 dB above the
output of a single quad amplifier.
