Abstract: Toroidal high dielectric ceramic microwave tuning probes are sliding on the central conductor of a high power electro-mechanical microwave dual-probe coaxial load pull tuner and create high reflection factor over a wide frequency range. The probes are positioned horizontally using a remote translation mechanism and allow continuous coverage of the Smith chart over a high frequency and VSWR (reflection factor) range. A remotely adjustable attenuator is inserted adjacent to the test port and mitigates spurious high reflection. A de-embedding calibration allows full tuner characterization in a few minutes instead of several hours.

Abstract: Coaxial load pull tuners use one horizontally-only moving metallic reflective probe inserted in the slabline at fixed penetration and an adjustable RF energy absorbing eccentrically into the slabline rotated disc. The tuner does not use high precision vertical axes. The remotely adjustable attenuator is inserted adjacent to the test port and mitigates spurious high reflection. Calibration procedures using de-embedding or adapter removal techniques allow high resolution full tuner characterization in a few minutes.

Abstract: A load-pull measurement system uses a PC controller, interface, calibration method and at least one new two-probe, waveguide slide screw impedance tuner; the tuner probes share the same waveguide section; they are inserted diametrically at fixed depth into facing each other slots on opposite broad walls of the waveguide. The tuner does not have cumbersome adjustable vertical axes controlling the penetration of the probes and its low profile is optimized for on-wafer operations. The carriages holding the probes are moved along the waveguide using electric stepper motors or linear actuators.

Abstract: A digital high-speed hybrid load pull test system comprises a slide screw automatic passive tuner, a digital active forward injection loop in a closed loop transmission configuration, calibration and tuning algorithms. The forward active injection loop comprises at least one adjustable coupler, a digital electronic tuner and feedback power amplifier; the passive tuner comprises one or more metallic tuning probes, used to create passive reflection factors. Small signal calibration of the passive and active tuners create a global calibration data base, used to pre-tune in the area of the target impedance and final high power (nonlinear) tuning employs a in-situ signal power wave search and measurement for digital impedances around the small signal pattern. The system provides for high speed low injected power tuning with maximum reflection factor at DUT reference plane reaching unity.

Abstract: A base-band (kHz to MHz range) very low frequency active impedance tuner allows controlling the reflection factor at a multitude of frequencies in the base-band for systematic evaluation of the effect of bias networks on nonlinear quantities of a RF transistor, like EVM and ACPR. It comprises an electronically controlled active heterodyne feedback loop, frequency mixing, filtering and a remotely controlled digital electronic tuner. The digital electronic tuning feedback module operates at standard octave band GHz range, which allows controlling impedances over several decades in the base-band frequency range.

Abstract: Low loss high directivity wire couplers use a transmission airline structure and a low diameter coaxial cable ending in a wire loop sensor, which is inserted into an elliptically formed conical opening of the ground wall of the transmission line and protrudes into its cavity leading into a coupled and an isolated port. Lower, capacitively induced, electrical currents, because of the protruding ground edges of the conical or recessed openings, compared with the unperturbed antiphase magnetically induced currents, lead to controlled higher directivity in a frequency range up to at least 170 GHz.

Abstract: A experimental matching network optimization method for two-stage power amplifiers combines existing technologies such as: Impedance tuners for load pull measurements, computers for RF network synthesis and analysis and numerical optimization algorithms, to create a method for in-situ experimentally verifying and optimizing the effect of matching network designs on overall amplifier performance before their manufacturing. The method eliminates guesswork in amplifier design, especially with regards to the interstage matching network of two-stage RF amplifiers. When properly implemented, the method revolutionizes MMIC amplifier design, by augmenting design confidence and bypassing costly hardware iterations.

Abstract: High power impedance tuners suffer from intense heating of the center conductor of the tuner airline (slabline), due to dissipated RF and DC power and, in addition to high electric field between the metallic tuning probe (slug) and the center conductor, also from associated thermal expansion causing sagging of the center conductor and possible electrical short. If the thermal expansion cannot be accommodated by structural means, the center conductor is cooled using forced air created by ventilators or re-circulating low loss dielectric liquid flowing through the slabline. Premature tuner aging through continuous airflow or cooling liquid circulation is avoided using real time monitoring of dissipated (heating) power and regulation of the cooling mechanism.

Abstract: A new load-pull tuner system using two-probe waveguide slide screw tuners of which the probes share the same waveguide section; they are inserted diametrically at fixed depth facing each other into slots on opposite broad walls of the waveguide. An adjustable broadband attenuator made using a resistive septum is inserted between the test port and the tuning probes. The tuner does not have cumbersome adjustable vertical axes controlling the penetration of the probes and its low profile is optimized for on-wafer operations. The carriages holding the probes are moved along the waveguide using electric stepper motors or linear actuators.

Abstract: A digital high-speed hybrid load pull test system comprises a slide screw automatic passive tuner, a digital active forward injection loop in a closed loop transmission configuration, calibration and tuning algorithms. The forward active injection loop comprises at least one adjustable coupler, a digital electronic tuner and feedback power amplifier; the passive tuner comprises one or more metallic tuning probes, used to create passive reflection factors. Small signal calibration of the passive and active tuners create a global calibration data base, used to pre-tune in the area of the target impedance and final high power (nonlinear) tuning employs a in-situ signal power wave search and measurement for digital impedances around the small signal pattern. The system provides for high speed low injected power tuning with maximum reflection factor at DUT reference plane reaching unity.

Abstract: A low radio frequency electro-mechanical load pull impedance tuner uses four rotary, remotely controlled variable shunt capacitors and three fixed series transmission lines to create up to 108 independently controllable impedance states at each frequency covering the entire Smith chart in the frequency range between 1 and 10 MHz; the capacitors and control motors and gear are immersed in high epsilon dielectric fluid inside individual sealed containers. Appropriate Error Function-based optimization algorithms, allow fast impedance tuning at the fundamental frequency at the output of DUT's operated in high gain compression. Stepper motors, drivers and control software are used to remotely control the variable shunt capacitors of the tuner and allow it to be automated, pre-calibrated and used in an automated load pull measuring setup.

Abstract: A low-profile impedance tuner uses a cam-driven piston-like vertical movement of a metallic tuning probe inside a low loss slabline, controlled by an eccentrically centered disc (cam), which is attached to the axis of a stepper motor and rotates parallel to the slabline walls. The structure combines the benefits of low profile rotating tuning probe control with the benign reflection factor phase trajectory of block tuning probes; this is critical for accurate interpolation and impedance synthesis (tuning) strategies using a limited number of calibration points, especially at high microwave and millimeter-wave frequencies.

Abstract: A wafer probe-to-waveguide adapter is transformed to a load pull device by integrating in the straight section of the waveguide a two-slug tuner with fixed penetration into diametral slots in the waveguide controlled by linear stepper actuators crossing over and sharing the same section of the waveguide.

Abstract: Combination tuning probes for slide screw load pull tuners allow larger frequency coverage Fmax/Fmin and higher GAMMA beyond the capacity of existing tuning probes. This is done by combining two or more equally or unequally long tuning slugs into a combination probe, the slugs being mounted in the same mobile tuner carriage using two or more independent vertical axes. To avoid spurious resonance phenomena the tuning slugs are driven parallel vertically in close proximity or sliding on each-other, are linked to each-other and guided appropriately allowing smooth, un-inhibited and continuous vertical movement of the metallic bodies.

Abstract: A new two-probe waveguide slide screw load-pull tuner of which the probes share the same waveguide section; they are inserted diametrically at fixed depth into facing each other slots on opposite broad walls of the waveguide. The tuner does not have cumbersome adjustable vertical axes controlling the penetration of the probes and its low profile is optimized for on-wafer operations. The carriages holding the probes are moved along the waveguide using electric stepper motors or linear actuators.

Abstract: A fast calibration method for slide-screw impedance tuners employs a new tuner control board and routine with independent direct triggering and data sampling by the VNA; a new vertical scaling algorithm bypasses the traditional iterative approach and uses numerical curve-fitting and ISO circle definition. Full tuner calibration executes without motor stopping, yielding time reduction typically by a factor of 8.

Abstract: A hermetically RF-EMI shielded 3-axis and planarity adjustable combo link assembly for low loss connection between the coaxial RF connector of external instruments (impedance tuners) with 30- or 45-degrees wafer probes allows continuous, micro-positioner controlled independent horizontal and vertical probe movement. Flexible sealing O-rings and RF absorbing sheets and gaskets ensure airtight and RF-EMI shielded operation.

Abstract: A low-profile slide screw impedance tuner with rotating disc-shaped tuning probes uses a mechanical arrangement for correcting the skewing of the reflection factor response of the rotating tuning probes. As the axis of the control motor turns, a protruding pin pushes against a fixed limit stop block and shifts the motor and its axis, and by that the tuning probe, in the opposite direction of the rotation shift. This corrects for the skewing phase rotation.

Abstract: A new method for calibrating slide screw tuners, both using hexahedron vertically moving and disc-shaped eccentrically rotating reflective tuning probes, allows straightening the reflection factor phase response (anti-skewing); it uses a new scaling method and a new coordinate system of tuning probe control. The method is agnostic and self-regulating, it treats the tuner as a black box and depends on the test frequency. The result is improved mathematical interpolation and tuning results using reduced number of calibration points and allowing higher calibration speed.

Abstract: A balanced on-wafer load pull tuner system includes an intelligent, independent and universal mechanical balancing and contact controlling device, supporting automatic microwave single or multi-probe slide screw tuners. It allows contacting and stable on-wafer testing of sub-micrometric devices. Ultra-low loss rigid airlines (bend-lines) used to connect the tuner with the semiconductor chips, in order to improve the tuning range at the DUT reference plane, transfer mechanical movements of the wafer probes attached to the rigid bend-lines, when the tuner mobile carriages move horizontally. A precisely controlled counter-weight allows contacting the DUT and balanced load pull operation by controlling the center of gravity of the assembly.