Pico VNA 108 - 8.5 GHz vector network analyzer

The PicoVNA 108 delivers an exceptional dynamic range of 124 dB at 10 Hz (118 dB for the PicoVNA 106) and less than 0.006 dB RMS trace noise at its maximum operating bandwidth of 140 kHz. The instruments can also gather all four S-parameters at each frequency point in just 182 µs (PicoVNA 106) or 189 µs (PicoVNA 108) or or S11 + S21 in less than 100 µs. In other words, a 201 point 2-port .s2p Touchstone file in less than 38 ms or up to two .s1p files in less than 20 ms. Their low price makes them cost-effective as deep dynamic range scalar network analyzers or single-port vector reflectometers as well as full-function dual-port, dual-path vector network analyzers. They are affordable in the classroom, in small businesses and even in amateur workshops, yet capable of meeting the needs of all users up to the laboratory or production test technician or the metrology expert.
 

Vector network analysis for the many

Once the domain of an elite few, microwave measurement has encroached into the lives of scientists, educators, surveyors, inspectors, engineers and technicians alike. Today’s microwave measurements need to be straightforward, portable, accurate, cost-effective and easy to learn.

PicoVNAs are all-new, UK-designed, professional USB-controlled, laboratory grade vector network instruments of unprecedented performance, portability and value for money. Despite their simple outline, small footprint and low cost, the instruments boast a four-receiver architecture to minimize the uncorrectable errors, delays and unreliability of internal transfer switches.

Vector network analysis everywhere

The PicoVNAs' small size, light weight and low cost suit them to field service, installation test, OEM embedded and classroom applications. With their remote automation capability, they are also attractive in applications such as:

8.5 GHz Network Metrology Training and Metrology Kits

In the classroom, Pico supports Network Metrology education through a low-cost, potentially one-per-student classroom kit. The Network Metrology Training Kit comprises PCB based passive and active circuit and transmission line examples, calibration standards and test leads, and for Microwave Office users, the project files used in its design. Just add the PicoVNA to start making and learning about network measurements and their critical role within the Design-Simulate-Implement-Measure design cycle.

Support for 8 and 12-term calibration and the unknown thru

Almost all vector network analyzers are calibrated for twelve error sources (six for each signal direction). This is the so-called 12-term calibration, which experienced VNA users are used to performing fairly regularly. In a four-receiver design some error sources are so reduced that 8-term calibration becomes possible, along with an important and efficient calibration technique known as the unknown thru. This gives the ability to use any thru interconnect (including the DUT) during the calibration process, vastly simplifying the procedure and reducing the number of calibration standards that need to be maintained. Advanced vector network analyzer users will be pleased to know that internal a-wave and b-wave data can be exported for diagnostic use.

Bias-Ts

Bias-Ts are often not provided, or available as costly extras, on other VNAs. Use the Pico VNA 106’s built-in bias-Ts to provide a DC bias or test stimulus to active devices without the complexity and cost of external DC-blocks. The bias is supplied from external power supplies or test sources routed to the SMB connectors adjacent to each VNA port.

Other I/O

Power (12 to 15 V DC @ 22 W) and USB 2.0 control are located on the rear panel. Trigger I/O for sweep synchronization and 10 MHz I/O for reference clock synchronization are available on four BNC sockets.

Test cables, adaptors, calibration standards and measurement check standards

A range of high-integrity RF and Microwave accessories are available from Pico Technology. Test cables and calibration standards strongly influence the overall performance of a VNA, so we recommend that you select your accessories and perform your calibrations carefully.

Cables and standards are often the weakest links in a VNA measurement, generally contributing significantly to measurement uncertainty despite their traditionally high cost. At the lowest levels of uncertainty, costs can be significant and measurements can be compromised by seemingly quite minor damage or wear. For these reasons, many customers hold both premium-grade items for calibration, reference or measurement standards, and standard-grade items as working standards and cables. Pico Technology now offers costeffective solutions in both grades. In general we recommend PC3.5 interfaces for premium or reference use and SMA interfaces for working use.
 

Phase- and amplitude-stable test leads

Two test cable types and grades are recommended and provided by Pico Technology. Both of high quality, with robust and flexible construction and stainless steel connectors, the main differences between them are the provision of PC3.5 or SMA test ports and the stability of their propagation velocity and loss characteristic when flexed; that is, the degree to which a measurement could change when the cables are moved or formed to a new position. Cables are specified in terms of flatness and phase variation at up to 8.5 GHz when a straight cable is formed as one 360° turn around a 10 cm mandrel.

PicoVNA 2 and PicoVNA 3 software

PicoVNA 2 and 3 present standard VNA measurement and calibration simply, intuitively and with efficient usage at its heart. The software offers a comprehensive range of measurements and plot formats in their one, two or four user-configurable measurement channels. All the standard vector network analyzer functions and tabulated measurements can be seen at a glance.

Save on trigger utility (PicoVNA 108)

Uniquely, benefiting from the fast measurement speed of the PicoVNA, save on trigger provides a fast and convenient method for capture and display of measurement data from multiple or changing device-under-test states. Think, for example, of variable attenuators, digitally configured filters, phase shifters or variable-gain amplifiers. Think also of devices under changing power supply, bias or environmental conditions, or even of a multiplexed measurement of a number of devices in the production environment. The PicoVNA can be set up to store up to 1024 triggered sweep measurements which can then be inspected, reordered and saved to disk in a number of formats. The trigger event can arrive on the external trigger input, or as a remote software trigger or a manual key press.

Captured measurement sweeps can be selected for display which, by default, shows one to four selected S-parameters across a maximum of 64 individually coloured traces, all plotted over the band of operation. The plotted sweeps can be any subset of all the captured sweeps and data can be normalized to one of the captured sweeps, which is useful for examining changes from sweep to sweep.

Mixer measurements utility (PicoVNA 108)

External local oscillator and external power sensor support

A wide range of mixer performance and port isolation measurements can be carried out, including swept RF or IF with a choice of low or high side LO. A PicoSource AS108 or a third-party signal source is used as the external LO source, and this operates under the control of the PicoVNA 3 PC application. The software also supports a third-party USB power sensor in the characterization of port power.

VSWR correction

Mixers can be difficult to measure accurately particularly when mixer port match is relatively poor. The PicoVNA 108 mixer measurement calibration includes the option of VSWR error correction. This reduces the conversion loss measurement uncertainty as typically shown in the diagram.

Mixer compression

Conversion loss change as a function of the input RF level is easily determined. This can be referenced either to the port power uncertainty of the PicoVNA or the user can use a third-party power sensor (above) to pre-characterize the PicoVNA 108 port power for enhanced accuracy. The 0.1 and 1 dB compression points are displayed on completion.