Impedance tuner systems and probes
An impedance tuner may include a shunt stub located at a fixed location along the transmission media, and a phase shifter to control the reflection phase. Another embodiment includes an adjustable length shunt stub connected on the transmission media, a variable phase shifter connected between the DUT port and the adjustable length shunt stub, a probe arranged for movement in a direction transverse to the direction of signal propagation. Another embodiment includes a reflection magnitude control system mounted in a fixed position relative to a direction of signal propagation along the transmission media, and a phase shifter to control a reflection phase.
1. An impedance tuner system, adapted to create a high reflection at at least one frequency within a tuning frequency range, comprising:
a transmission media for propagating RF signals;
a shunt stub located at a fixed location along the transmission media; and
a phase shifter to control the reflection phase.
2. The impedance tuner system of claim 1 , wherein said specified frequency is a harmonic frequency.
3. A load pull measurement system, comprising the tuner system of claim 1 .
4. The impedance tuner system of claim 1 , wherein the shunt stub has a variable length to provide frequency tuning of the high reflection.
5. The impedance tuner system of claim 4 , wherein the shunt stub length and the phase shifter are controlled by an electronic control system.
6. A impedance tuner system, comprising:
a transmission media for propagating RF signals;
an adjustable length shunt stub connected on the transmission media;
a device-under-test (DUT) port for connection to a DUT;
a variable phase shifter connected between the DUT port and said adjustable length shunt stub;
a probe mounted along the transmission media and arranged for movement in a direction transverse to said direction of signal propagation;
the shunt stub, the probe and the phase shifter in combination adapted to provide independent tuning at a fundamental frequency and a harmonic frequency.
7. The tuner system of claim 6 , wherein the probe is fabricated of a single section.
8. The tuner system of claim 6 , wherein the probe is fabricated of a plurality of sections.
9. A method for operating the tuner system of claim 6 , comprising:
adjusting the length of the shunt stub to give maximum reflection at the harmonic frequency and low reflection at the fundamental frequency as seen at the DUT port;
adjusting the phase shifter to give a desired phase at the harmonic frequency as seen at the DUT port;
moving the probe to set an impedance at the fundamental frequency at the DUT port, compensating for the positions of the shunt stub and phase shifter.
10. A load pull measurement system, comprising the tuner system of claim 6 .
11. An impedance tuner, comprising:
a transmission media for propagating RF signals, said transmission media comprising a center conductor and a ground plane;
a reflection magnitude control system mounted in a fixed position relative to a direction of signal propagation along said transmission media; and
a phase shifter to control a reflection phase; and
wherein the reflection magnitude control system includes a means for varying impedance by moving the ground plane relative to the center conductor.
12. The tuner of claim 11 , wherein an impedance of at least one section of the reflection magnitude control system is higher than a characteristic transmission line impedance of the impedance tuner system.
13. The tuner of claim 11 , wherein an impedance of at least one section of the reflection magnitude control system is lower than a characteristic transmission line impedance of the impedance tuner system.
14. The tuner of claim 11 , wherein an impedance of at least one section of the reflection magnitude control system is higher than a characteristic transmission line impedance of the impedance tuner system, and wherein an impedance of at least one section of the reflection magnitude control system is lower than a characteristic transmission line impedance of the impedance tuner system.
15. A load pull measurement system, comprising the tuner of claim 11 .
16. A high reflection impedance tuner system, comprising:
a transmission media for propagating RF signals;
a shunt stub with a tunable length connected on the transmission media at a fixed location relative to a direction of signal propagation along the transmission media to create a high reflection at a reflection frequency, and wherein the tunable length of the shunt stub provides frequency tuning of the high reflection;
a variable phase shifter connected on the transmission media to control a phase of the reflection.
17. The tuner system of claim 16 , wherein the tunable length of the shunt stub and the variable phase shifter are manually controlled.
18. The tuner system of claim 16 , further comprising an automated control system for controlling the tunable length of the shunt stub and the variable phase shifter.
19. A load pull measurement system, comprising the tuner system claim 16 .