Nortel microwave module
Gain or phase control, using many chained sections. Each section has a pair of forward-or-reverse-biased diodes as variable shunt resistances or capacitances to ground, with a branchline coupler to make the reflections from these two diodes cancel, to present a nice 50 ohm impedance at the input and output.
The "F2L" diodes are HP HSMP-3802 microwave PIN diodes, which suggests attenuators. But who knows, maybe some of the sections are for attenuation and some are for phase shift.
More details on attenuators (if the diodes are forward-biased): www.microwaves101.com/encyclopedias/reflection-attenuators
More details on making phase shifters with quadrature couplers (if the diodes are reverse-biased): www.microwaves101.com/encyclopedias/varactor-phase-shifters
Nortel microwave module
Gain or phase control, using many chained sections. Each section has a pair of forward-or-reverse-biased diodes as variable shunt resistances or capacitances to ground, with a branchline coupler to make the reflections from these two diodes cancel, to present a nice 50 ohm impedance at the input and output.
The "F2L" diodes are HP HSMP-3802 microwave PIN diodes, which suggests attenuators. But who knows, maybe some of the sections are for attenuation and some are for phase shift.
More details on attenuators (if the diodes are forward-biased): www.microwaves101.com/encyclopedias/reflection-attenuators
More details on making phase shifters with quadrature couplers (if the diodes are reverse-biased): www.microwaves101.com/encyclopedias/varactor-phase-shifters