Digital load pull tuner
View Patent ↗A digital high-speed load pull tuner comprises a slide screw automatic tuner in a traditional reflection configuration and an active forward injection loop using a digital tuner in a transmission configuration. The forward active injection loop comprises two compact signal couplers of which at least one is adjustable, a digital tuner, circulator, feedback power amplifier; the passive tuner comprises one or more remotely controlled mobile carriages sliding along the slabline and carrying metallic tuning probes, used to create passive reflection factors. The incoming signal is sampled, modulated in amplitude and phase by the digital tuner and fed back into the slabline synchronizing with the passive reflected signal, to create a partially virtual load presented to the DUT.
1. A closed loop hybrid (active & passive) load pull tuner,
comprises:
a digital, high-speed, active tuner and a passive pre-matching tuner as integrated parts of the closed loop,
including:
a slabline having a test port, an idle port, a center conductor, and
two alongside the slabline sliding, remotely controlled, mobile carriages #1 and #2,
an adjustable signal coupler,
a circulator having, in signal flow, ports #1, #2 and #3,
a remotely controlled high-speed digital electronic tuner having a test port and an idle port,
an amplifier having an input port and an output port, and
a fixed signal coupler,
each said signal coupler having an input, an output, a coupled and an isolated port;
wherein
the coupled port of the adjustable coupler is connected with port #1 of the circulator,
port #2 of the circulator is connected with the test port of the digital electronic tuner,
port #3 of the circulator is connected with the input port of the amplifier,
the output port of the amplifier is connected with the coupled port of the fixed coupler;
and wherein
the mobile carriage #1 is inserted between the test port of the slabline and the mobile carriage #2,
the mobile carriage #2 is inserted between the mobile carriage #1 and the fixed coupler.
2. The closed loop hybrid load pull tuner of claim 1 ,
wherein
the adjustable signal coupler is attached to a remotely controlled vertical axis of the mobile carriage #1,
a metallic tuning probe, capacitively coupled with the center conductor of the slabline is attached to a remotely controlled vertical axis of the mobile carriage #2.
3. The closed loop hybrid load pull tuner of claim 2 ,
wherein
the adjustable signal coupler comprises a U-formed sensor, insertable into a slot of the slabline and electro-magnetically coupled with the center conductor,
and wherein
one branch of the U-formed sensor is the coupled port and the other branch is the isolated port of the adjustable signal coupler.
4. The closed loop hybrid load pull tuner of claim 2 ,
wherein
the isolated ports of the signal couplers, the idle port of the slabline and the idle port of the high-speed digital electronic tuner are terminated with a matched load.