Hybrid electro-mechanical tuner
View Patent ↗A hybrid electro-mechanical tuner uses a modified version of the forward injection technique, also called Gamma Boosting Unit (GBU), integrated with a passive slide screw impedance tuner in the same slabline and housing. The modified GBU samples a phase-and-amplitude adjustable portion of the forward travelling signal at the fundamental frequency, amplifies it and injects it back, in reverse direction, into the main signal path through a circulator connected at the idle port of the tuner, after the mechanical tuning probe. The horizontal and vertical control of the forward coupler (wave-probe) of the modified GBU which is attached to the vertical axis in a mobile carriage, is manual or remote and eliminates the need for a dedicated phase shifter and attenuator, making the solution better, simpler and more effective.
1. A hybrid (active/passive) impedance tuner comprising
(a) a passive, electro-mechanical tuner and
(b) an active feedback injection loop,
whereby
(a) the passive tuner comprises
a low loss parallel plate airline (slabline) having an input (test) port and an output (idle) port and a center conductor joining the ports,
and at least one mobile carriage #1 sliding along the axis of the slabline and having a vertically movable axis,
whereby a reflective probe is mounted on the vertical axis, said probe being insertable into the slot of the slabline and capacitively coupled with the center conductor;
and
(b) the active feedback injection loop comprises
(b1) a bidirectional coupler (wave-probe) mounted on the vertical axis of a mobile carriage #2 sliding along the axis of the slabline, whereby the vertical axis controls the penetration of the wave-probe into the slot of the slabline,
wherein carriage #2 is placed between the test port and carriage #1;
(b2) a power amplifier having an input and an output port;
(b3) a circulator having three ports, 1, 2 and 3, signal flow being from port 1 to port 2, from port 2 to port 3 and from port 3 to port 1, whereby port 3 is terminated with characteristic impedance;
wherein
the coupled port of the wave-probe is connected to the input port of the amplifier, the output port of the amplifier is connected to port 1 of the circulator and port 2 of the circulator is connected to the idle port of the slabline.
2. The tuner of claim 1 , whereby the mobile carriages and their vertical axes are attached to stepper motors using appropriate gear and remotely controlled using controller and software.
3. The tuner of claim 1 , whereby the horizontal movement of carriage #2 and vertical movement of the axis of carriage #2 are manually controlled using micrometric screws and gear, and the horizontal movement and vertical axis movement of carriage #1 are automated using stepper motors, appropriate gear, controller and software.