Focus recommends TRL Calibration Kits for applications such as load pull & noise parameters. Due to high reflection and low loss, tuner S-parameter measurements represent a challenge for VNA’s, because of error term determination and coupler directivity. Long experience has taught us not to rely on other calibration techniques than TRL (Thru-Reflect-Line). The popular SOLT technique is conditionally useable, but not guaranteed, up to 4GHz. The much convenient ECal method has provided questionable and inconsistent results. Our Customers are advised to be very careful with VNA calibrations, because the whole measured data depends on that.
Accessories
Different Accessories
TRL Calibration Kits
Because of this, and to save our customers time and doubt, Focus has developed and offers a set of precise and reliable TRL calibration kits from 0.03 to 110 GHz with the following connector types: 7/16, N, APC-7, 3.5mm, 2.9mm, 2.4mm, 1.85mm, WR-15, WR-10. Our calibration kits are compatible with all commercial network analyzers.
RF Test Fixtures
Focus’ modular microstrip, high power and ultra low loss coaxial RF Test Fixtures are designed mainly for load pull testing of packaged transistors. All Focus test fixtures come with TRL calibration standards and support most transistor packages sized from less than 0.1″ and up to 1″.
Special designs include:
- Decade wide (Fmax:Fmin ~10:1) Klopfenstein transformers,
- Water and Air cooling and
- On substrate bias networks.
- Microstrip fixtures (PTJ-x*; Packaged Test Jig) are available with 50Ω lines or built-in λ/4 or taper (Klopfenstein) transformers, harmonic traps and DC bias networks
- Minimum Loss coaxial Test Fixtures (MLTF-x*) (insertion loss < 0.03 dB at 2 GHz) are available with 7mm, N and 7/16 connectors in frequency ranges up to 18 GHz. (US patent 6,464,513)
Both RF Test Fixture types can be fitted with water cooling for RF power up to several hundred Watts.
(*) ‘-x’ indicates the frequency range: DC-4GHz, -6GHz, -12GHz and -18GHz.
Noise Modules
Noise measurements allow the determination of the four Noise Parameters of a device (transistor). Focus’ Noise Modules integrate well with various third party noise receivers.
Noise Parameters: These are four numbers that fully describe the noise behaviour of an active or passive device (twoport) at a given frequency. For practical reasons we use the following quantities as Noise Parameters:
Focus’ noise parameter extraction routines leverage the PNA-X’s unique implementation
of the cold-source noise figure measurement technique. This specific technique requires a noise source to determine the kBG (gain-bandwidth constant) of the system and a passive mechanical tuner is used to characterize the noise receiver across both the impedance and frequency space. This step is imperative to obtain fully vector-source-corrected measurements.
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 speed and performance.
Bias Tees
Pulsed Bias tees with a perfect balance of RF performance and DC power handling
Auriga’s Pulsed Bias Tees balance impressive RF performance with heavy-duty power handling across multiple frequency bands ranging from 100 MHz to 26.5 GHz. They are designed for rigorous usage without sacrificing RF performance. Only the highest-quality materials are used to minimize signal loss and enable efficient heat removal.
These highest-power bias tees include a fast-acting fuse to protect DUTs against current spikes. A DC sense port is provided for accurately measuring the incident DC voltage. Bias tees requiring external heat sinking include pre-tapped holes for easy mounting.
Auriga high power bias tees are also often used Wideband modulation applications, where attention is needed to properly terminate the impedances seen at the baseband frequencies.
Typical applications for Auriga bias tees are high power pulsed IV, pulsed load pull, wideband noise parameter extraction and pulsed s-parameter (used in compact modelling)
Focus is now introducing new 50 and 67GHz models for wideband noise and high power pulse applications. Leveraging decades of design work on high power bias-tees these new bias-tees offer great power handling for applications like 5G which also requires broad frequency coverage and very good baseband termination to allow for wideband signals operating at >20GHz.