Hybrid harmonic impedance tuner

Patent metadata

Field	Value
Publication number	US-10177429-B1
Application number	US-201715628770-A
Country	US
Kind code	B1
Filing date	Jun 21, 2017
Priority date	Jun 22, 2016
Publication date	Jan 8, 2019
Grant date	Jan 8, 2019

Abstract

A hybrid harmonic slide screw tuner uses the forward injection technique, also called Gamma Boosting Unit (GBU) cascaded with two independent tuning probes in the same slabline and housing. The wave-probes used in the GBU sample a portion of the forward travelling signal, adjusts its phase, amplifies it, adjusts its amplitude (attenuation) and couples it back, in reverse direction into the main signal path. In the present active tuner technique as is herein implemented, the passive tuners and the signal couplers are mounted on the same double carriages which move each carriage horizontally and the wave- and tuning probes vertically, independently. Appropriate calibration and tuning algorithms ensure independent hybrid (active and passive) harmonic tuning.

First claim

What I claim as my invention is:

1. A hybrid harmonic impedance tuner comprising,
two ports, an input (test) port and an output (idle) port, and a slotted airline (slabline) between the ports,
at least two mobile carriages sliding independently along the axis of the slabline and having two independent vertically movable axes each,
an external amplifier having an input and an output port,
and characteristic impedance (Zo) terminations;
whereby each carriage carries one signal coupler (wave-probe) on one axis and one reflective (tuning) probe on the other axis,
and whereby carriage #1 carries wave-probe #1 and tuning probe #1 and carriage #2 carries wave-probe #2 and tuning probe #2;
whereby carriage #1 and carriage #2 are travelling on cascaded sections of the slabline;
and whereby the wave-probes and the tuning probes are insertable to adjustable depth into the slot of the slabline;
and whereby a coupled port of one wave-probe is connected to the input port of the amplifier and the output port of the amplifier is connected to a coupled port of the other wave-probe and whereby an isolated port of the wave-probes is terminated with Zo.

2. A compact hybrid harmonic slide screw impedance tuner comprising,
two ports, an input (test) port and an output (idle) port, and a slotted airline (slabline) between the ports, said slabline comprising two parallel vertical conductive walls and a center conductor between the ports;
and at least two mobile carriages sliding independently along the axis of the slabline and having two independent vertically movable axes each,
an external amplifier having an input and an output port,
and characteristic impedance (Zo) terminations;
whereby each carriage carries one signal coupler (wave-probe) on one axis and one reflective tuning probe on the other axis,
and whereby carriage #1 carries wave-probe #1 and tuning probe #1 and carriage #2 carries wave-probe #2 and tuning probe #2;
and whereby the carriages are mounted diametric on top and bottom of the slabline sharing the same section of the slabline,
and whereby the wave-probes and the tuning probes are insertable to adjustable depth into the slot of the slabline from opposite directions;
and whereby a coupled port of one wave-probe is connected to the input port of the amplifier and the output port of the amplifier is connected to a coupled port of the other wave-probe and whereby an isolated port of the wave-probes is terminated with Zo.

3. The tuner of claim 1 or 2 , whereby the horizontal position of the carriages along the slabline and their vertical axes are remotely controlled using appropriate gear, electrical stepper motors, control electronics, processor and control software.

4. A calibration method, wherein the tuner of claim 3 is connected to a pre-calibrated vector network analyzer (VNA) using RF cables and to a control computer using digital cable; and scattering (s−) parameters are measured by the VNA between the input (test) port and the output (idle) port of the tuner at the fundamental frequency (Fo) and at least one harmonic frequency (2Fo, 3Fo, . . . ), for various settings of the wave-probes (horizontal position WX and vertical position WY) and the tuning probes (horizontal position TX and vertical position TY), the settings being controlled by the computer, which is in operative communication with the VNA, in following steps:
a) all wave-probes and tuning probes are withdrawn from the slabline and s-parameters of the tuner (slabline) are measured at all selected frequencies and saved in an initialization matrix [S00];
b) wave-probe #1 is inserted into the slabline in a number of vertical steps WY1.j and for each WY1.j it is moved horizontally in a number of steps WX1.i;
c) s-parameters [S1(WX1.i,WY1.j)] are measured between the input and output ports and saved;
d) wave-probe #1 is withdrawn and steps b) and c) are applied to wave-probe #2 resulting in a matrix [S2(WX2.i,WY2.j)];
e) both wave-probes are withdrawn;
f) tuning probe #1 is inserted into the slabline in a number of vertical steps TY1.j and for each TY1.j it is moved horizontally in a number of steps TX1.i;
g) s-parameters [S3(TX1.i,TY1.j)] are measured between the input and output ports and saved;
h) tuning probe #1 is withdrawn and steps f) and g) are applied to tuning probe #2 resulting in a matrix [S4(TX2.i,TY2.j)];
i) s-parameters of all probes (wave-probes and tuning probes) at all horizontal and vertical settings, except of the probe whose horizontal position (X) is closest to the test port, are de-embedded using matrix [S00] −1 ;
j) cascaded permutations of all s-parameter matrices, [S1] to [S4], are created in computer memory and saved in calibration files for all selected frequencies for later use.

5. A tuning method for the tuner uses calibration data generated in claim 4 as follows:
a) s-parameters are loaded in memory for selected frequencies Fo, 2Fo, 3Fo . . . ;
b) error function EF is generated comprising the sum of vector differences between target reflection factor S11.T(F) and calibrated reflection factor S11.C(F) for all selected frequencies F=Fo, 2Fo, 3Fo . . . ;
c) a search algorithm through the s-parameter space selects the carriage positions TX1, TX2 (or WX1, WX2) and vertical axis (probe) positions WY1, WY2, TY1, TY2 corresponding to minimum error function EF in step b);
d) carriages and vertical axes are positioned as in step c).

6. Interpolated reflection factors S11(F) at each frequency (F) are used in claim 5 , instead of calibrated ones.

Assignees

• Tsironis Christos

Inventors

• Tsironis Christos

Classifications

• H03J1/14

  Special arrangements for fine and coarse tuning · CPC title

• H01P5/04 Primary

  with variable factor of coupling · CPC title

• G01R27/32

  in circuits having distributed constants {, e.g. having very long conductors or involving high frequencies} · CPC title

• H03H7/38

  Impedance-matching networks · CPC title

• H03H7/40

  Automatic matching of load impedance to source impedance · CPC title