Programmable harmonic amplitude and phase controller

Patent metadata

Field	Value
Publication number	US-10276910-B1
Application number	US-201715610018-A
Country	US
Kind code	B1
Filing date	May 31, 2017
Priority date	May 31, 2016
Publication date	Apr 30, 2019
Grant date	Apr 30, 2019

Abstract

A continuously adjustable programmable harmonic microwave attenuator and linear phase controller (HAPC) uses mobile signal couplers (wave-probes) in a slabline structure which is terminated with 50 Ohms. The coupled ports of the wave-probes are connected with the output port of the unit via a power combiner using flexible RF cables. The wave-probes are attached to the vertical axes of mobile carriages, which are placed at variable distances from the input port, corresponding to the expected transmission phases, whereas the depth, at which the wave-probes are inserted into the slabline, determines the coupling factors and thus the value of the attenuation. The unit can be calibrated at a number of harmonic frequencies typically equal to the number of the wave-probes used.

First claim

What I claim is:

1. An adjustable harmonic RF attenuation and transmission phase controller (HAPC) having an input and an output port and transmission media between the ports;
whereby the transmission media comprises a cascade of slotted airline (slabline), at least two adjustable signal couplers (wave-probes #1, #2, . . . ) mounted on the slabline, a multi-port signal combiner having at least two input ports and one output combination port, and flexible RF cables;
and whereby the signal, comprising fundamental and harmonic components, enters the input port, traverses part of the slabline and is coupled into each wave-probe;
and whereby the signal coupled into each wave-probe is injected into an associated input port of the signal combiner and the combined signal exiting from the combination port of the signal combiner is extracted from the output port;
whereby the coupling factors between the wave-probes and the transmission airline control the amplitude and the physical distances of the wave-probes from the input port control the phase of the transmission factor of the HAPC between input and output ports at the fundamental and harmonic frequencies.

2. A HAPC as in claim 1 , whereby the slotted airline (slabline) comprises two ports, two sidewalls and a center conductor;
and whereby one port of the slabline serves as the input port of the HAPC,
and the other port of the slabline is terminated with characteristic impedance (Zo).

3. A HAPC, as in claim 2 having at least two mobile carriages sliding independently horizontally along the slabline, each said carriage having a vertical axis.

4. A HAPC as in claim 3 , whereby the wave-probes are attached to the vertical axis of the associated carriages, move horizontally with the carriages and can be inserted independently into the slot of the slabline.

5. A HAPC as in claim 4 , whereby the vertical axes are remotely controlled allowing independent adjustment of the coupling factors between the center conductor of the slabline and the wave-probes.

6. A HAPC as in claim 5 , whereby the carriages are remotely controlled.

7. A HAPC as in claim 2 , whereby the coupled ports of the signal couplers are connected to the input ports of the signal combiner using flexible RF cables and whereby the output port of the signal combiner is connected to the output port of the HAPC and whereby the isolated ports of the couplers are terminated with characteristic impedance (Zo).

8. A HAPC as in claim 2 or 7 , whereby Zo is 50 Ohms.

9. A calibration method for HAPC as in claim 8 , wherein the HAPC is connected to a pre-calibrated vector network analyzer (VNA) using RF cables and to a control computer using digital cables;
and scattering (s−) parameters are measured by the VNA between the input port and the output port of the HAPC at the fundamental frequency (Fo) and at least one harmonic frequency (N*Fo), for various settings of the coupling factors and the distances between the couplers and the input port, the settings being controlled by the computer, which is in operative communication with the VNA, whereby N=2, 3 . . . , in following steps:
a) all wave-probes are initialized (withdrawn from slabline) and s-parameters of the HAPC are measured and saved in a matrix [S00];
b) wave-probe #1 is inserted into the slabline in a number of steps Y 1 .j and for each Y 1 .j it is moved horizontally in a number of steps X 1 .i;
c) s-parameters [S1(X 1 .i,Y 1 .j)] are measured between the input and output ports and saved;
d) wave-probe #1 is initialized and step b) is applied to wave-probe #2 resulting in a matrix [S2(X 2 .i,Y 2 .j)];
e) steps c) and d) are applied to all other wave-probes, whereby all wave-probes remain initialized except for the wave-probe being controlled and measured;
f) s-parameters of all wave-probes, except wave-probe #1, are de-embedded (cascaded with [S00] −1 );
g) permutations of all s-parameter matrices are created in computer memory and saved in calibration files for all selected frequencies for later use.

10. A tuning (transmission factor synthesis) method for HAPC between input port ( 1 ) and output port ( 3 ), uses calibration data generated in claim 9 as follows:
h) s-parameters are loaded in memory for selected frequencies F=Fo, 2Fo, . . . NFo;
i) error function EF is generated comprising the sum of vector differences between target transmission factor S31.T(F) and calibrated transmission factor S31.C(F) for all selected frequencies F=Fo, 2Fo, . . . NFo;
j) a search algorithm through the s-parameter space selects the carriage positions X 1 , X 2 , . . . XN and vertical axis positions Y 1 , Y 2 , . . . YN corresponding to minimum error function EF in step b);
k) carriages and vertical axes are positioned as in step c).

11. Interpolated transmission factors S31(F).I at each frequency (F) are used in claim 10 , instead of calibrated ones.

Assignees

• Tsironis Christos

Inventors

• Tsironis Christos

Classifications

• H01P1/222

  Waveguide attenuators (H01P1/23 takes precedence) · CPC title

• H01P5/183 Primary

  at least one of the guides being a coaxial line · CPC title

• H01P1/182

  Waveguide phase-shifters (H01P1/181, H01P1/185, H01P1/19 take precedence) · CPC title

• H03H7/40

  Automatic matching of load impedance to source impedance · CPC title

• H01P1/225

  Coaxial attenuators (H01P1/23 takes precedence) · CPC title