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Patent Analysis of

Transistor test fixture with integrated couplers and method

Updated Time 12 June 2019

Patent Registration Data

Publication Number

US10001521

Application Number

US14/541622

Application Date

14 November 2014

Publication Date

19 June 2018

Current Assignee

TSIRONIS, CHRISTOS

Original Assignee (Applicant)

TSIRONIS, CHRISTOS

International Classification

G01R31/302,G01R31/26,G01R35/00,G01N22/00

Cooperative Classification

G01R31/2607,G01N22/00,G01R35/00,G01R1/045,G01R31/2601

Inventor

TSIRONIS, CHRISTOS

Patent Images

This patent contains figures and images illustrating the invention and its embodiment.

US10001521 Transistor test fixture integrated 1 US10001521 Transistor test fixture integrated 2 US10001521 Transistor test fixture integrated 3
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Abstract

Microwave transistor test fixtures, both micro-strip and coaxial, include integrated wideband directional signal sensors/couplers and allow the detection of the main signal and its harmonic components, injected into and delivered by a transistor in high power operation mode, by using a phase-calibrated network or signal analyzer and allows this way the reproduction of real time signal waveforms. The fixtures are best calibrated using equivalent TRL calibrated fixtures allowing overcoming the incompatibility of the internal ports connecting to the transistor terminals with coaxial cables attached to VNA.

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Claims

1. A radio frequency (RF) transistor (device under test, DUT) test fixture comprising test ports and coupled ports in a single housing as follows: an input test port and an output test port, a main signal transmission line segment connecting said input test port with the input terminal of said DUT and a main signal transmission line segment connecting the output terminal of said DUT with said output test port of said fixture, and signal bi-directional coupling section(s), inserted between the terminal(s) of said DUT and the associated test port(s), whereby said bi-directional coupling sections comprise a forward coupling port and a reverse coupling port, said coupled ports being operationally connectable with a signal analyzer, which detects the phase and amplitude of the signal waves propagating on said signal transmission lines towards and away from said DUT.

2. The test fixture as in claim 1, in which said main signal transmission lines are microstrip lines and each said signal coupling section comprises a wire bridge between two secondary microstrip lines, each said secondary line leading to an external coaxial connector attached to said fixture, said external coaxial connectors being operationally connectable with the said signal analyzer, and whereby said wire bridge is placed, in a non-contacting relation, in the immediate proximity of the said signal transmission line.

3. The test fixture as in claim 1, in which said main signal transmission line is a microstrip line and each said signal coupler comprises a wire bridge between the center conductors of two coaxial cables, each said coaxial cable leading to an external coaxial connector attached to said fixture, said external coaxial connectors being operationally connectable with the said signal analyzer, said wire bridge being placed, in a non-contacting relation, in the immediate proximity of the main signal transmission line.

4. The fixture as in claim 2 or 3, whereby said wire bridge overlaps, in a non-contacting manner, with the signal transmission line.

5. The test fixture as in claim 1, in which said main signal transmission line is a microstrip line and each said signal coupling section comprises a conductive microstrip section between two secondary microstrip lines leading to coaxial connectors attached to said fixture, said connectors being operationally connectable with the said signal analyzer; and whereby said conductive microstrip section is placed in a non-contacting relation in the immediate proximity, approximately parallel, to the said main signal transmission line.

6. A radio frequency (RF) test fixture comprising two test ports, an input test port and an output test port, a main signal transmission line segment connecting said input test port with the input terminal of the device under test (DUT) and a main signal transmission line segment connecting the output terminal of said DUT with said output test port of said fixture and at least one signal bi-directional coupling section inserted between said DUT terminals and said fixture test ports in the same housing, whereby said input and output segments are slablines comprising two parallel conductive plates and a center conductor, and whereby said bi-directional signal coupling section(s) comprise electric and magnetic field sensors allowing measuring amplitude and phase of the signal waves, said sensors being placed between the DUT terminals and the test ports, said sensors being operationally connectable to a signal analyzer.

7. The test fixture as in claim 6, whereby said signal coupling sections are wave-probes, said wave-probes comprising a short section of exposed center conductor forming a bridge between the center conductors of two joined coaxial cables, said exposed center conductor section being placed, in a non-contacting manner, close to the center conductor of said input and output slabline sections parallel to said center conductor, said coaxial cables being operationally connected to a signal analyzer.

8. The test fixture as in claim 6, in which said electric and magnetic field sensors are placed next to each other and perpendicular to the center conductor.

9. The test fixture as in claim 6, in which said electric and magnetic field sensors are placed perpendicular to each-other, the magnetic field sensor being placed parallel to the sidewall and perpendicular to the center conductor and the electric field sensor being inserted through a hole in the sidewall perpendicular to and in the proximity of the center conductor of said slabline.

10. The test fixture as in claim 2 or 3 or 5 or 6 or 7 or 8 or 9, in which the characteristic impedance Zo of said transmission lines is 50 Ohm.

11. The test fixture as in claim 2 or 3 or 5 or 6 or 7 or 8 or 9, in which the characteristic impedance Zo of any said transmission line, is different than 50 Ohm.

12. A calibration method for radio frequency (RF) transistor test fixtures (TTF), whereby said fixtures comprise distinct input and output sections and directional coupling sections associated with both input and output sections, said fixtures having input port A and output port B; and input coupled ports C and D and output coupled ports E and F; and internal ports G and H connecting to the DUT, whereby port G connects to the input DUT terminal and port H to the output DUT terminal, said calibration method comprising the following steps: a) an equivalent RF test fixture (ETF) having an input port I and output port J, and two distinct sections, an input and an output section, said input section having a coaxial port I and an internal port K and said output section having an internal port L and a coaxial port J, said ports being connected to each-other using transmission lines; and using coaxial connectors at ports I and J, said fixture ETF is calibrated using standard TRL method on a pre-calibrated vector network analyzer, hereby extracting s-parameter matrices for said input and output sections of said ETF; b) s-parameters of said input and output sections of said ETF are saved as matrices [SA] and [SB] correspondingly; c) the input and output sections of TTF and ETF are separated; d) the input section of TTF is connected at internal port G with internal port L of the output section of said ETF and s-parameters are measured between ports A and J as well between ports J and C and J and D and saved; e) s-parameters measured in step d) are de-embedded (cascaded using the inverse matrix [SB]) and saved; f) the output section of TTF is connected at internal port H with internal port K of the input section of said ETF and s-parameters are measured between ports I and B as well between ports I and E and I and F and saved; g) s-parameters measured in step f) are de-embedded (cascaded using the inverse matrix [SA]) and saved.

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Claim Tree

  • 1
    1. A radio frequency (RF) transistor (device under test, DUT) test fixture comprising
    • test ports and coupled ports in a single housing as follows: an input test port and an output test port, a main signal transmission line segment connecting said input test port with the input terminal of said DUT and a main signal transmission line segment connecting the output terminal of said DUT with said output test port of said fixture, and signal bi-directional coupling section(s), inserted between the terminal(s) of said DUT and the associated test port(s), whereby said bi-directional coupling sections comprise a forward coupling port and a reverse coupling port, said coupled ports being operationally connectable with a signal analyzer, which detects the phase and amplitude of the signal waves propagating on said signal transmission lines towards and away from said DUT.
    • 2. The test fixture as in claim 1, in which
      • said main signal transmission lines are microstrip lines and each said signal coupling section comprises
    • 3. The test fixture as in claim 1, in which
      • said main signal transmission line is a microstrip line and each said signal coupler comprises
    • 5. The test fixture as in claim 1, in which
      • said main signal transmission line is a microstrip line and each said signal coupling section comprises
  • 6
    6. A radio frequency (RF) test fixture comprising
    • two test ports, an input test port and an output test port, a main signal transmission line segment connecting said input test port with the input terminal of the device under test (DUT) and a main signal transmission line segment connecting the output terminal of said DUT with said output test port of said fixture and at least one signal bi-directional coupling section inserted between said DUT terminals and said fixture test ports in the same housing, whereby said input and output segments are slablines comprising two parallel conductive plates and a center conductor, and whereby said bi-directional signal coupling section(s) comprise electric and magnetic field sensors allowing measuring amplitude and phase of the signal waves, said sensors being placed between the DUT terminals and the test ports, said sensors being operationally connectable to a signal analyzer.
    • 7. The test fixture as in claim 6, whereby said signal coupling sections are wave-probes, said wave-probes comprising
      • a short section of exposed center conductor forming a bridge between the center conductors of two joined coaxial cables, said exposed center conductor section being placed, in a non-contacting manner, close to the center conductor of said input and output slabline sections parallel to said center conductor, said coaxial cables being operationally connected to a signal analyzer.
    • 8. The test fixture as in claim 6, in which
      • said electric and magnetic field sensors are placed next to each other and perpendicular to the center conductor.
    • 9. The test fixture as in claim 6, in which
      • said electric and magnetic field sensors are placed perpendicular to each-other, the magnetic field sensor being placed parallel to the sidewall and perpendicular to the center conductor and the electric field sensor being inserted through a hole in the sidewall perpendicular to and in the proximity of the center conductor of said slabline.
  • 12
    12. A calibration method for radio frequency (RF) transistor test fixtures (TTF), whereby said fixtures comprise distinct input and output sections and directional coupling sections associated with both input and output sections, said fixtures having input port A and output port B; and input coupled ports C and D and output coupled ports E and F; and internal ports G and H connecting to the DUT, whereby port G connects to the input DUT terminal and port H to the output DUT terminal, said calibration method comprising the following steps:
    • a) an equivalent RF test fixture (ETF) having an input port I and output port J, and two distinct sections, an input and an output section, said input section having a coaxial port I and an internal port K and said output section having an internal port L and a coaxial port J, said ports being connected to each-other using transmission lines; and using coaxial connectors at ports I and J, said fixture ETF is calibrated using standard TRL method on a pre-calibrated vector network analyzer, hereby extracting s-parameter matrices for said input and output sections of said ETF;
    • b) s-parameters of said input and output sections of said ETF are saved as matrices [SA] and [SB] correspondingly;
    • c) the input and output sections of TTF and ETF are separated;