FOCUS MICROWAVES GROUP

Non-Linear Measurements using PNA-X

V02/19powered by FOCUS MICROWAVESHybrid Load Pull & Behavior Modeling with PNA-X
Hybrid active Load Pull combines the benefits of bothpassive and active Load Pull techniques in one setup. Active Load Pull is the only method that allows
reaching the low internal impedance of power transistors, especially on wafer and at very high frequencies.
The system relies on the basic concept of using a passive
electromechanical tuner as a prematch to get closer tothe device’s conjugate output impedance, then complementing with active injection, the system can tune impedances anywhere in the Smith chart and beyond ( ≥ 1).
The measurements themselves are “travelling wave” based,
performed using a Keysight PNA-X. With the introductionof prematching tuners, the feedback injection signal pow-Setup

er remains close to the DUT output power not only at thefundamental frequency but at the very important harmonic frequencies, whereas in pure active systems, the power
amplifier has to produce very high power (up to 20 times
the DUT power) to compensate for the strong mismatch
between the impedance of the feedback injection amplifier (50Ω) and the DUT internal impedance (0.5 - 1Ω).
The user can also add optional signal generators todrive the load not only at the fundamental but at
the harmonic frequencies. Keysight’s X-series family of signal generators can be used as well as thehigh end PSG analog or vector signal generator.

MXG

PSG

PNA-X

Optional Outputs

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Wideband Noise Parameter Extraction with PNA-X
Focus’ noise parameter extraction routines leverage thePNA-X’s unique implementation of the cold-source noise
figure measurement technique. This specific techniquerequires a noise source to determine the kBG (gain-bandwidth constant) of the system and a passive mechanicaltuner is used to characterize the noise receiver acrossboth the impedance and frequency space. This step isimperative to obtain fully vector-source-corrected measurements.

Focus’ system architecture supports all of the X-series analyzers. Key- sight’s N9069A/W9069A noise fig- ure measurement application uses the Y-factor method to calculate the noise figure.

Considered as an industry standard for decades theN897XA family of noise figure analyzers is still supported
by Focus’ FDCS measurement suite.

For mmwave applications a RF down conversion stage
might be required if the frequency of noise measured exceeds the receiver’s bandwidth. Focus offers noise modules which support down conversion for optimal speedand performance.

Setup
NFA

ZVA 67

PNA-X

X-Series

Optional Inputs

DC Power Supply

DUT
Bias Tee

CCMT- 50 GHz Tuner
Tuner
CCMT16-45GHz

Bias Tee

ONM

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Pulsed IV and Compact Modeling with PNA-X
The Focus Compact Model (FCM) utility is a streamlined
software package designed to be used with Focus’
AURIGA high-end pulse system,that is used togenerate Compact Models for transistors from their
Pulsed-IV and wideband pulsed s-parameter data.
The FCM utilses Keysigth’s PNA-X platform tomesaurement highly accurate pulsed s-parametersof the device under test. Keysight’s PNA-X support
both wideband and narrow band detections offergin
greater flexibility and performance. These techniques

let the user trade dynamic range for speed, with theresult almost always yielding faster measurements
than those obtained by conventional filtering.
The PNA-X’s four internal pulse generators and pulse
modulators, two internal sources with a combining
network, and active-application options provide fully
integrated pulsed active-device characterization.

PNA-X

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info@focus-microwaves.com+1 514 684 4554

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